NAT'L INST. OF STAND & TECH R.I.C.

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NISI

PUeUCATIONS

NIST TN 1423

Analysis of High Bay Hangar Facilities

FOR Fire Detector Sensitivity

AND Placement

Joseph E. Gott, Naval Facilities Engineering Command

and

Darren L. Lowe, Kathy A. Notarianni and William Davis

National Institute of Standards and Technology

QC

100

.U5753

NO 1423

1997

Nisr

U.S. Department of Commerce

Technology Administration

National Institute of Standards and Technology

Sponsored by:

U.S. Department of the Navy

Naval Facilities Engineering Command

Naval Air Systems Command

NIST TECHNICAL NOTE 1423

Analysis of High Bay Hangar Facilities for

Fire Detector Sensitivity and Placement

Joseph E. Gott

Darren L. Lowe

Kathy A. Notarianni

William Davis

Building and Fire Research Laboratory

National Institute of Standards and Technology

Gaithersburg, MD 20899

February, 1997

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U.S. Department of Commerce Sponsored by:

William M. Daley, Secretary U.S. Department of the Navy

Technology Administration Naval Facilities Engineering Command

Mary L. Good, Under Secretaryfor Technology Naval Air Systems Command

National Institute of Standards and Technology

Arati Prabhakar, Director
National Institute of Standards U.S. Government Printing Office For sale by the Superintendent of

and Technology Washington: 1997 Documents

Technical Note 1423 U.S. Government Printing Office

Natl. Inst. Stand. Technol. Washington, DC 20402

Tech. Note 1423

319 pages (February 1997)

CODEN: NTNOEF
HI

EXECUTIVE SUMMARY

Current guidelines for designing fire protection systems for aircraft hangars were developed with the

primary objective of saving the building, and with less consideration given to minimizing damage to the

hangar's contents. The high cost of modern aircraft justifies reexamining present fire detection and

sprinkler activation methods to determine if new approaches could lead to a quicker response to a smaller

fire, with the benefit of substantially reduced damage to aircraft adjacent to the fire source. The Naval

Facilities Engineering Command (NAVFAC) established a unique Government/industry partnership to evaluate detector and sprinkler activation in aircraft hangars. The results of this comprehensive program

are reported in this document.

Since the establishment of the original guidelines for aircraft fire protection, the use of JP-4 as the

primary aviation jet fuel has been superseded by JP-5 and JP-8, both of which have significantly higher

flash points, and composite materials are now commonly integrated into the structures of military

aircraft. As a result, both the hazard and risk associated with hangar fires have been modified. So too,

fire detection and sprinkler activation methods have continued to evolve. An experimental approach was

chosen to determine how the latest generation of fire detectors and sprinkler heads respond to increasing

sizes of fires. Actual hangars were used to ensure the impact of the ceiling height and geometry were

factored into the behavior of the fire plumes. This was critical because the early studies used to evaluate

sprinkler activation were limited to ceiling heights below 10 m.

Thirty-three full-scale experiments were conducted using JP-5 and JP-8 fuels in two Navy high bay

aircraft hangars located at the Naval Air Stations in Barber's Point, Hawaii and Keflavik, Iceland. The

full-scale test fires produced heat release rates ranging from 100 kW to 33 MW. Over 200 instruments,

sprinklers and detectors were used in each full scale experiment to measure the behavior of heat and

smoke in high bay areas, and their effect on the response time of fire detection and sprinkler systems.

The test matrix also included analyzing the effects of draft curtains, ambient temperature, flat versus curved ceilings, and open versus closed hangar doors.

Analysis of the measurements described in this report yield the following signiflcant findings regarding

fire detection in aircraft hangars:

• Experiments with varied spacing of spot-type heat detectors at the ceiling showed that spacing

could be increased to 12.2 m (40 ft) between detectors without any significant reduction in response time.

• The most effective spot-type heat detectors were found to be rate-compensated detectors with a temperature rating approximately equal to that of the automatic sprinklers (i.e., 79 °C).

• For a line-type heat detector installed horizontally below a nominally flat hangar roof, the

temperatures as indicated by the thermocouples located adjacent to the detector are almost the same as the single temperature indicated by the detector. Thus, line-type detectors could be

reliably used in hangars with flat roofs provided set points can be established to initiate an alarm.

The set points may be established by using the experimental results of this study and applying

computer modeling as necessary to extend the results to conform with the desired geometry.
iv Executive Summary

• Under a curved hangar roof, the use of line-type heat detectors requires additional study and

installation experience to determine spacing and installation requirements.

• Projected beam smoke detectors installed in accordance with their current listing requirements

proved ineffective because the dense smoke obscured the optical path, which resulted in the

initiation of a trouble alarm. However, if the sensitivity of the projected beam detectors is decreased in the proper manner (which is outside current listing requirements), early and reliable

response by these detectors can be obtained. This requires further testing and approval by a

certified testing laboratory, as well as investigating the effects that the modified detector settings

will have on the initiation of trouble alarms.

• Spot-type smoke detectors, which currently are not used in hangars, were able to detect the fires easily even when installed on the 15 m and 22 m high ceilings, indicating their potential in other

high ceiling applications. Smoke detector spacings as far as 12.2 m (40 ft) apart at the tested

heights exhibited no significant reduction in response time. The present practice prescribed in NFPA 72 is to reduce detector spacing for ceilings as high as those examined in this study.

• The response of the combination ultraviolet/infrared detectors when set to the current industry

requirements previously established for JP-4 vC'as satisfactory in tests using JP-5 and JP-8 jet fuel

fires.

• Controller-based optical detectors offer design flexibility that can be exploited to achieve faster response times.

• New test standards need to be developed for optical detectors sensing jet fuel pool fires if damage to aircraft adjacent to the incident aircraft is to be prevented.

The following results apply to sprinkler applications in high bay hangars:

• With proper activation, closed head automatic sprinklers may provide the same level of

structural protection as the deluge systems required by NFPA 409 without the problems

associated with overhead deluge systems in the event of a false alarm.

• The 79 °C (175 °F) quick response heads proved to be the only effective sprinklers in high bay

hangar applications for the fire sizes studied.

• Draft curtains control the flow of heat and smoke, and increase the number of sprinklers

activated as well as decrease the response times. The installation of draft curtains should be

considered a part of the fire protection arsenal for all high bay aircraft hangars.

• A comparison of response times for wet-pipe sprinklers versus dry-pipe (or pre-action) sprinklers

showed no significant difference for these fast growing fires.

• Quick response sprinklers respond faster and are likely to be more effective in a hangar

application.
Executive Summary v

The large data base generated by this project warrants additional analysis. However, the application of

existing fire models to a number of the experimental fires reveals the following:

• The probabilistic fire correlations and zone models that did not account for the presence of a hot

ceiling layer underpredicted the fire centerline temperature. When the model applications were

consistent with the physical situation simulated, however, reasonable accuracy in predicting

plume centerline temperatures was achieved.

• Unconfined ceiling correlations used to predict sprinkler activation proved unsatisfactory due to the importance of the hot layer on the phenomena. When the presence of the layer was included,

the prediction of sprinkler activation improved substantially near the plume centerline, but

within the ceiling jet at substantial distances from the plume centerline, the predictions were

unsatisfactory.

• The data base assembled with these experiments can be used as a baseline to develop fire protection strategies at other heights. These data can also serve as the starting point for the

development, improvement, and validation of fire models and fire correlations in high ceiling

spaces.

Navy and DoD criteria have and will continue to change as a result of this project. The National Fire

Protection Association's "Sta;ndard on Aircraft Hangars," NFPA 409, should be reevaluated based on the

data in this report.

In addition to this printed document, a video record of a number of the test fires conducted during this project is available upon request from NAVFAC and NIST.
VI

Smoke billowing from aircraft hangar following jet fuel fire test at Naval Air Station, Keflavik, Iceland.
Vll TABLE OF CONTENTS

Page

EXECUTIVE SUMMARY iii ACKNOWLEDGMENTS ix

1 INTRODUCTION 1

2 JET FUEL POOL BURNING RATES 5

3 WARM CLIMATE EXPERIMENTS - 15 m HIGH FACILITY 11

3.1 Experimental Set-up 11 3.1.1 Building Specifications of 15 m High Facility 11 3.1.2 Measurements - Fire Protection Devices 12

3.1.3 Measurements - Instrumentation 33

3.2 Test Fires -15 m High Facility 41

3.2.1 Logic Used to Determine Experimental Fire Sizes 43

3.2.2 Computer Modeling of 15 m Facility 43

3.2.3 Experimental Procedures and Test Information 44

3.2.4 Fuel Specifications 48

3.3 Fire Behavior in 1 5 m Hangar 51

3.3.1 Behavior of Detector Fires 51

3.3.2 Behavior of Sprinkler Fires 62

3.4 Response of Detection and Sprinkler Activation Systems to Fires 80

3.4.1 Sprinkler Activation Times 80

3.4.2 Response of Projected Beam Smoke Detectors 89

3.4.3 Response of Photoelectric Smoke Detectors 92

3.4.4 Response of Single Point Heat Detectors 97

3.4.5 Response of Optical Flame Detectors 102

3.4.6 Response of Line-Type Heat Detector 108

4 COLD CLIMATE EXPERIMENTS - 22 m HIGH FACILITY 121

4.1 Experimental Set-up 121

4.1.1 Building Specifications 121

4.1.2 Measurements - Fire Protection Devices 122

4.1.3 Measurements - Instrumentation 137
Vlll

Page

4.2 Test Fires in 22 m High Facility 144

4.2.1 Rationale for Experimental Fire Sizes 144

4.2.2 Computer Modeling of 22 m Facility 145

4.2.3 Experimental Procedures and Test Information 152

4.2.4 Fuel Specifications 156

4.3 Behavior of Fires in 22 m Hangar 157

4.3.1 Detector Fires 157

4.3.2 Sprinkler Fires 163

4.3.3 Open Door Experiments 192

4.4 Response of Detection and Sprinkler Activation Systems to Fires 218

4.4.1 Sprinkler Activation Times 218

4.4.2 Response of Projected Beam Smoke Detectors 225

4.4.3 Response of Photoelectric Smoke Detectors 239

4.4.4 Response of Heat Detectors 248

4.4.5 Response of Optical Flame Detectors 259

4.4.6 Response of Line-Type Heat Detector 274

5 APPLICATION OF FIRE MODELS 285

6 CONCLUSIONS AND RECOMMENDATIONS 293

6.1 Observations on Behavior of Fires 293

6.1.1 Experimental 293

6.1.2 Numerical Models 294

6.2 Summary of Detection System Performance 295

6.2.

1

Detection of Smoke 295

6.2.2 Detection of Heat 296

6.2.3 Detection of Flame Radiation 297

6.3 Summary of Sprinkler Activation Performance 297

6.4 Overall Conclusions and Specific Recommendations 298

7 REFERENCES 301

APPENDIX

Wood Crib Fire Tests, 1 5 m High Facility 305
IX ACKNOWLEDGMENTS

This project was a unique government and industry partnership. The project team consisted of the Naval

Facilities Engineering Command, the Naval Air Systems Command, representatives from the U.S. Air

Force, the U.S. Army and the U.S. Marine Corps, private sponsors representing the United States' fire alarm and sprinkler industry, and the National Institute of Standards and Technology. This project would

not have been possible without the support from each of these organizations.

We gratefully acknowledge the support of Naval Air Systems Command, especially Mr. John Stebbings,

and the following industry sponsors: Simplex Time Recorder Co., The Viking Corporation, Detector

Electronics Corporation, Detection Systems, Inc., and Alison Control, Inc. These private industry

sponsors not only provided financial assistance, but they also supplied equipment, engineering services,

personnel, and technical expertise.

Special thanks go to the Commanding Officer of the Naval Air Station (NAS) at Barbers Point, Hawaii,

Captain E. Waller, USN, and the Commanding Officer of the NAS, Keflavik, Iceland, Captain W.R.

Blake, Jr., USN, who trusted the research team enough to allow us to bum large fires in their aircraft

hangars. We would also like to thank the Public Works Officers and staffs of NAS Barbers Point,

Hawaii, and NAS Keflavik, Iceland, especially Commander J.R. Reddish, USN. Lieutenant Commander

E. Clarkson, USN. We also gratefully acknowledge the support and cooperation of the Federal Fire

Department, Pearl Harbor, Hawaii, and the fire department at the NAS Keflavik, especially Fire Chief H.

Stefansson, Deputy Fire Chief A. Eiriksson, Assistant Fire Chief S. Arason, and their staff without

whose constant support this project would not have been possible.

The completion of this project required a great deal of time, effort, and support from many fire protection

engineers within the Naval Facilities Engineering Command. Special thanks goes to the Atlantic

Division, NAVFAC, especially Vince Donnally, Ralph Luca, Phil Bolton, and Ardith Mock; the Pacific

Division, NAVFAC, especially Joe Condlin, John Chan, Emily Chun, and Jordan Lau; the Engineering

Field Activity, Chesapeake, especially Joe Simone, Diane Pitts, and Tony Militello; the Engineering

Field Activity, Northwest, especially Rita Fisher; and the Public Works Center, Washington DC,

especially Chris Scheer and Suzette Hartman. Special thanks go to the staff at NAVFAC Headquarters,

especially Dave Peterson, Jay Bordwell, and Traci Bangor, whose contributions are too numerous to list. We would like to gratefully acknowledge Dr. Get Moy, Captain K. Gross, USN, Captain E. Rushing,

USN, and Mr. Harry Zimmerman at NAVFAC headquarters for their support and commitment to this project.

Assistance from other fire protection engineers at other military branches was also essential to the

project. Fred Walker, Mike Davis, and Jim Crawford from the U.S. Air Force, Kevin King from the

U.S. Marine Corps, and Bob DiAngelo and Ed Lockwood from the U.S. Army Corps of Engineers were

crucial to the planning, engineering and successful execution of this project.

The National Institute of Standards and Technology provided this project with an extensive support staff

in addition to the authors. We greatly appreciate the work and technical expertise provided by Dr. William Grosshandler, Mr. Michael Glover, Ms. Anabisdally-Boden Irizarry, and Mr. Scott Laramee.

This report required a significant amount of technical investigation, data reduction and analysis, data
X Acknowledgments

processing and writing. In addition to the primary authors, this report is a collaboration of the following

contributing authors: Chris Scheer, Suzette Hartman, Diane Pitits, Tony Militello, Dave Peterson, Jay

Bordwell, Traci Bangor, and Scott Laramee.
1 INTRODUCTION

1.1 Background

The design of fire protection systems for high bay aircraft hangars poses the same challenges and

problems as those encountered in a variety of tall structures including hotel atria and warehouses.

Unfortunately, the model building codes and fire codes in the United States offer little or no guidance

for the design of fire protection systems for high bay spaces. This is because of a lack of scientific data

regarding the behavior of heat and smoke in ceiling heights over 9.1m. Timely detection of a fire is more difficult in tall structures due to the distance heat and other products of combustion must travel to reach sprinklers and detectors. Stratification may also occur, which poses an additional challenge in selecting the optimal location of detectors.

The Navy and all military services within the U.S. Department of Defense (DoD) are responsible for

providing fire protection systems capable of protecting DoD assets around the world. This includes the

protection of high value military aircraft which are maintained and repaired in high bay aircraft

hangars. These aircraft are an essential element of a strategic military force whose mission is unparalleled by commercial aircraft. The Naval Facilities Engineering Command (NAVFAC) is responsible for the design, construction and maintenance of all shore-based facilities at U.S. Navy and

Marine Corps bases worldwide.

For years, NAVFAC has designed fire protection systems for aircraft hangars based on the

requirements developed to protect commercial aircraft hangars [1]. However, the scope of NFPA 409

is limited to the protection of the hangar itself, not the aircraft. Current NFPA 409 requirements for

Type I aircraft hangars include foam-water deluge sprinkler systems and, in some cases, supplementary

underwing foam-water systems as well as hand-held hose systems. These criteria were developed

primarily to protect the hangar building from a large spill fire, and are based on a series of tests conducted for the Navy and the Air Force involving fire sizes approximately 9.1 m x 9.1 m.[l] These

tests were based on JP-4 fuel which has a flash point of approximately -8 °C. The military stopped

using JP-4 as their primary jet fuel circa 1986, and changed to JP-5 and JP-8 whose flash points are approximately 60 °C and 38 °C respectively.

Fire protection design criteria for Navy aircraft hangars have evolved over the years. Many of the

existing hangars were built in the World War II era, and their fire protection consists solely of

overhead deluge sprinkler systems activated by pneumatic rate-of-rise heat detectors. With the

development of aqueous film-forming foam (AFFF), the Navy's design criteria were changed to include

overhead AFFF deluge sprinkler systems, a variety of new detection systems, and in many cases, supplementary underwing foam monitor nozzles. In essence, this reflects the current requirements of

NFPA 409 for commercial aircraft hangars. However, overhead foam-water deluge systems have

caused countless, costly problems in military aircraft hangars.

Both the Navy and Air Force have been plagued with false activations involving foam-water deluge

sprinkler systems over aircraft with open cockpits. These false activations have been caused by

numerous sources including lightning strikes which introduce transient voltage spikes into the fire alarm

system, water hammers in aging underground water distribution systems, accidental releases by

maintenance personnel, deliberate acts of vandalism, accidental activation of manual pull stations,

failure of pressure relief valves at pumping stations, roof water leakage into overhead heat detection

systems, and false activation of fire detection systems. This prompted all branches of DoD to pursue

alternative fire protection designs which would provide an equivalent level of protection.
2 1 Introduction

The first alternative was to utilize closed-head foam-water sprinkler systems at the ceiling, which are now a part of the DoD criteria for hangar protection. The challenge was to design a closed-head

sprinkler system which would respond like a deluge system given a spill fire in the hangar. One of the

goals of this project was to investigate that design approach, and determine what fire sizes would

activate a variety of sprinkler heads and detection systems. Current NFPA requirements for closedhead foam-water sprinkler systems state that the temperature rating of sprinkler heads must be within

the range of 121 °C to 149 °C (250 °F to 300 °F) [2]. The research team believed these temperature

ratings were too high to have the sprinklers activate in a reasonable time frame, and that lower

temperature, quick response heads could function similarly to a deluge system without the false alarm

problem. Consequently, a variety of temperature ratings were investigated to improve the overall

response time of the closed-head sprinklers.

While it is readily accepted that conventional hangar fire protection systems are not designed to extinguish a three-dimensional fire, fire protection engineers within DoD believe that properly designed

AFFF extinguishing systems are capable of controlling a spill fire and limiting the spread of most fires to the adjacent aircraft.

The second significant ahernative was to shift the primary suppression responsibility to the foam-water

monitor nozzles, rather than the ceiling-level systems, and then find the quickest and most reliable means of detecting a spill fire. Optical detectors have neither been approved nor tested for JP-5 and

JP-8. Their present listings are for JP-4 and only evaluate their response to three fire sizes at arbitrarily determined distances.

The Building Fire and Research Laboratory (BFRL) at the National Institute of Standards and

Technology (NIST) has conducted previous experiments and modeling studies of high bay hangars [3]

.

Those experiments utilized isopropyl alcohol, involved a single fire size, and were conducted with the

hangar doors in the closed position. Effective hangar fire protection must consider the possibility of the

hangar doors being in the open position because it presents a more challenging fire scenario for

detection. The current study investigates the effects of open hangar doors and additional fire configurations on hangar fire detection systems.

Computer fire models could be used to assist in designing the fire protection systems for buildings with

high bay ceilings. While the advanced field models may be capable of handling this task, few design

engineers have the equipment, the training or the time required to run such complex models. The

existing zone models (e.g., CFAST) and special purpose deterministic models (e.g., FPETOOL and

DETACT) do not provide reliable predictions for the activation of detectors and automatic sprinklers in

buildings with high ceilings [3] . This is due to the fact that most of the existing models were developed

based on correlations from fire tests conducted with ceiling heights not exceeding 9.1 m [4]. Prior to

this project, only very limited experimental data had been collected regarding the activation of

sprinklers and detectors at ceiling heights over 9.1 m.

1.2 Scope of Investigation

A jet fuel spill fire poses a severe threat to military aircraft within high bay hangars. By the time a pool fire grows to the equivalent size of the 9. 1 m by 9. 1 m JP-4 pool fire originally used to test the

response of sprinkler systems installed in hangars, collateral damage to adjacent aircraft is almost

assured. While it is likely that an aircraft intimate to the ignition source will be lost to a jet fuel fire, the
1 Introduction 3

goal within DoD is to have a fire protection system capable of protecting other aircraft originally not involved in the fire, as well as to protect the hangar structure itself. This investigation was designed to determine how quickly various sprinklers and detectors would respond to the smoke and heat release

rate of fires much smaller than that created by a 9. 1 m by 9. 1 m JP-4 pool.

In addition to fire size, the switch from previously used JP-4 jet fuel to currently used JP-5 and JP-8

reduces the heat release rate, which is likely to extend the time to detection. Higher ceilings also lead

to longer times to system activation. As a result, it was important to capture both the fuel type and

actual hangar geometry effects in the test plan.

This study consisted of 33 full-scale fire experiments in two Navy high bay aircraft hangars. The

movement of smoke and heat as well as the response of detection and suppression devices in high bay

hangars under a variety of conditions were measured and analyzed. These data will be used by fire protection engineers in the Navy as well as the other military services to reevaluate fire protection

criteria for military aircraft hangars.

Experiments were conducted in two distinctly different climates to understand how smoke movement

and detector sensitivity are impacted by ambient temperature. One set of experiments was conducted in a 15 m high aircraft hangar at the U.S. Naval Air Station in Barbers Point, Hawaii. A second set of

experiments was conducted in a 22 m high aircraft hangar at the U.S. Naval Air Station in Keflavik,

Iceland. The 15 m hangar had a nominally flat roof, while the 22 m hangar had a curved roof. In

addition, a number of laboratory-scale burn tests were conducted to determine the burn rates of JP-4,

JP-5 and JP-8 aviation fuels.

The overall objective of these investigations was to provide insight into the behavior of realistic jet fuel

fires in aircraft hangars as that behavior impacts the design and operation of various fire protection

systems. The specific parameters investigated included the following:

Burn rates of JP-4, JP-5 and JP-8

• Heat release rates for a variety of a JP-5 and JP-8 pool fires

• Effectiveness of spot-type and line-type heat detectors for high bay hangars

• Spacing of spot-type detectors in high bay hangars

• Approximate minimum fire size threshold for each detector type

• Effect of fuel type on the response of each type of fire detector

• Response distance thresholds of optical detectors to various fire sizes and fuel types

• Effects of temperature, stratification and wind on detector performance

• Overall performance of heat, smoke and projected beam detectors in high bay hangars

• Approximate minimum fire size for sprinkler activation for various sprinkler heads

• Effects of draft curtains on sprinkler and detector response

• Effects of an open-door fire on detector and sprinkler response

• Effects of ceiling configuration on detector and sprinkler response

1.3 Organization of Report

Extensive field measurements were conducted at two different facilities. The results of the fire tests conducted in the 15 m high hangar in Hawaii are reported in Section 3. Section 4 deals with the fire
4 1 Introduction

tests conducted in the 22 m high facihty in Iceland. Within each of these major sections, the

experimental set-up and instrumentation are described, followed by a description of the fires and

operational procedures. The corresponding experimental results are then presented in each major

section, respectively.

Prior to the field tests, experiments were held in the NIST facility to determine the burning rates of JP4, JP-5 and JP-8. These are presented first, in Section 2. The ability of simple correlations to predict

the measured ceiling temperatures and sprinkler activation times is explored briefly in Section 5 . The

major conclusions and recommendations generated from the project are summarized in Section 6. Additional data on wood crib fires collected during the course of this study but outside the primary

focus of the report are found in the Appendix.
2 JET FUEL POOL BURNING RATES

A series of laboratory scale experiments were performed at NIST to determine heat release rates and

burning rates as a function of fire size for JP-4, JP-5, and JP-8 jet fuels. These laboratory scale

experiments were conducted using a cone calorimeter and the NIST large calorimeter. Results were

used to determine appropriate fire sizes for the large scale tests.

These jet fuels were selected because of their widespread use in military aircraft. The fuels were tested

and shown to meet Military Specifications MIL-T-5624P for JP-4 and JP-5 [5], and MIL-T-83133D for

JP-8 [6]. Table 1 shows these specifications which define heating value, density, and flash point of

each fuel.

Table 1. Military Specifications for aviation fuel used in experiments

Fuel Higher Heating Value

MJ/kg

Density @ 15 °C

kg/L

Flash Point

°C

JP-4 42.8 0.751 -0.802 -8^

JP-5 42.6 0.788 - 0.845 60

JP-8 42.8 0.775 - 0.840 38

^ Flash point as statecI in NRL Report 7549 [10]

2.1 Measurements of Heat Release Rate and Burning Rate

The heat release rates for each fuel type were determined using oxygen consumption calorimetry

techniques. A discussion of the principles of oxygen consumption calorimetry can be found in

reference [7]. To summarize the method, all gaseous combustion products from the fire are directed

through a duct where mass flow and oxygen concentration are measured as a function of time. Using

these measurements, the rate of oxygen consumption is determined. For most fuels, the heat release

rate is proportional to the rate of oxygen consumption. A load cell measured mass loss as a function of

time. Dividing the rate of mass loss by the pan area yielded burning rates (kg/m^-s) for each test.

2.2 Cone Calorimeter Results

The laboratory scale experiments were comprised of nine tests, three repeat tests for each of the three

fuels. A schematic of the Cone Calorimeter apparatus is shown in Figure 1. The ignition source was a small propane torch. As discussed in ASTM E-1354 [8], the heat release rates measured using the

Cone Calorimeter have an uncertainty defined by r = 75.5 H- 0.13 q"„^, where r is the error band for

tests conducted at the same facility and q ",^ is the maximum heat release rate per unit area (kW/m-)

for all of the tests considered in the sample. The maximum heat release rate used in the above

expression was from the test with the highest average heat release rate for each fuel. Table 2 lists the

estimated uncertainty and the range of values measured for each fuel.
2 Jet Fuel Pool Burning Rates

Table 2. Cone calorimeter results for jet fuels burning in 0.085 m diameter pan

Fuel Number of

Tests

Mean Heat Release Rate

(kW/m^)

Burning Rate

(g/mVs)

JP-4 3 395 ± 67 9.26 ± 0.34

JP-5 3 333 ± 58 7.01 ± 0.70

JP-8 3 316 + 55 6.93 + 0.87

Table 3. Large scale hood calorimeter results for jet fuel fire tests

Fuel Tests Pan Dia.

m

Pan Area

m^

Steady State HRR

kW, + 15%

Burning Rate

kg/m^/s

JP-4 3 1.0 0.79 1,900 0.094+0.020

JP-4 1 1.2 1.13 2,500 0.066+0.010

JP-5 2 1.0 0.79 1,400 0.070+0.010

JP-5 2 1.2 1.13 2,000 0.060+0.010

JP-8 3 1.0 0.79 1,500 0.086+0.020

JP-8 2 1.2 1.13 2,200 0.060+0.010
2 Jet Fuel Pool Burning Rates

Laser extinction beam including

temperature measurement

Temperature and differential pressure measurements taken here

-Soot sample tube location

Exhaust

blower

Soot collection filter Cone heater

Exhaust

hood

Spark igniter

Sample

Load cell

Vertical orientation

Figure 1

Diagram of cone calorimeter apparatus used for small-scale heat release

measurements.
8 2 Jet Fuel Pool Burning Rates

2.3 NIST Large Calorimeter Results

Thirteen fire tests were conducted in the NIST large calorimeter for JP-4, JP-5, and JP-8. Heat release

rates as a function of pan size were determined using oxygen consumption calorimetry for a 1.0 m (3.3

ft) diameter and a 1.2 m (3.9 ft) diameter circular pan. The NIST large calorimeter uses the same

principles as for small scale oxygen consumption calorimetry, but the mass flow rate is averaged over

nine points across the duct diameter. Also, the oxygen concentration is measured after being collected

where the combustion products are considered well mixed. Each fire was ignited using a propane torch

with a 6.4 mm (0.25 in) nozzle made of copper tubing.

The uncertainty associated with the NIST large calorimeter is estimated to be 15 %. This estimate is based on a 5 % uncertainty in assuming a constant net heat of combustion for all fuels as discussed in

[9], a 5 % measurement uncertainty in pitot tube pressure, and up to 5 % measurement uncertainty in the remaining equipment.

Table 3 shows the heat release rates and burning rates for tests conducted in the NIST large

calorimeter. For the two 1.0 m diameter pan fires of JP-5, the average heat release rate was 1300 ±

100 kW. The average burning rate for JP-5 for the 1.0 m circular diameter pan was 0.07 + 0.01

kg/m^/s. Figure 2 shows a representative heat release rate curve for each fuel. For a 1 .0 m diameter

pan, JP-5 had the lowest heat release rate of the three fuels, with an average heat release rate during

steady state burning of 1300 kW for the test shown. JP-4 had a higher heat release rate, about 1900

kW during steady state burning for the same pan size. The JP-4 fire also grew to steady state faster than both JP-5 and JP-8, due to its much lower flash point. The JP-8 fuel had an average heat release

rate of 1500 kW during steady state burning, closer to the heat release rate for JP-5. Referring to Table 3, the heat release rates for these two fuels are also similar for the 1.2 m circular diameter pan,

with average heat release rates for JP-5 and JP-8 of 2000 kW and 2200 kW, respectively.

Heat release rate as a function of pan size is an important parameter needed to determine appropriate

fire sizes for the full scale tests. As Figure 3 illustrates, the heat release rate increases with the

increase in pan size, increasing from a steady state average heat release rate of 1300 kW for a 1.0 m

diameter pan to 2000 kW for a 1.2 m diameter pan of JP-5 fuel.
2 Jet Fuel Pool Burning Rates

2500

2000

B 1500

(0 OH

Q)

(0

(0o

I? 1000

(0

0) I

500

100 200 300

Time (s)

400 500

Figure 2. Heat release rate versus time for 1.0 m diameter pool fires of JP-4, JP-5, and

JP-8.
10 2 Jet Fuel Pool Burning Rates

2500

2000

S 1500

a:

(D

(A

(0

_g)

t? 1000

ro

(D I

500

1.0 m Pan

1.2 m Pan

100 200 300

Time (s)

400 500

Figure 3. Heat release rate versus time for 1.0 m and 1.2 m diameter pool fires using

JP-5.
11

WARM CLIMATE EXPERIMENTS - 15 m fflGH FACILITY

The Naval Air Station at Barbers Point, Hawaii, was selected as representative of a warm climate

installation, where high normal operating temperatures might be expected to impact the flow of a fire plume and the choice of sprinkler activation temperature. The nominal height of the aircraft hangar in

which the full-scale fire tests were conducted is 15 m. The layout of the building is described in the

following section. The type of fire protection and suppression devices installed, the instrumentation

used to monitor the fire, and the experimental results are presented. In addition, the methodology used

to design the fire experiments and analyze the results is provided.

3.1 Experimental Set-up

3.1.1 Building Specifications of 15 m High Facility

The first series of full scale fire experiments was conducted in Hangar 11 1 at the Naval Air Station in

Barbers Point, Hawaii. This hangar was built in 1942 and consists of one large hangar maintenance

bay and two adjoining office spaces. A plan view of the hangar bay and fire area are shown in Figure

4. For the purpose of this section, all references to compass direction are made with respect to test north as shown in the Figure 4.

The hangar bay dimensions are approximately 97.8 m (321 ft) in length and 73.8 m (242 ft) in width.

The maximum ceiling height is 14.9 m (49 ft) located directly over the centerline of the hangar bay.

The east and west walls are comprised of concrete masonry construction with numerous unprotected

window and door openings into the hangar bay. These walls are two stories in height and provide a

non-fire rated separation between the office space and the hangar bay. The north and south ends of the

hangar bay consist of metal and glass horizontal sliding hangar doors which are manually operated.

This hangar has no existing heating ventilation and air conditioning system.

The roof consists of built-up tar and gravel over a corrugated metal deck. The roof slopes from a height of 14.9 m (49 ft) at the center of the hangar toward the east and west walls which are 13.4 m

(44 ft) high. The metal deck is directly supported by 0.25 m (10 in) I beams which run the (N-S) width

of the hangar and are spaced 4. 1 m (13.5 ft) on center. The I beams are supported by open steel trusses which run perpendicular to the beams (E-W) and are spaced 6.1m (20 ft) on center. These

trusses span the full length of the hangar. A picture of the roof assembly is shown in Figure 5. The

roof also contains two skylights each of which measures 73.2 m (240 ft) long, 6.1 m (20 ft) wide, and

3.7 m (12 ft) high. The skylights are 36.6 m (120 ft) apart and run parallel to the hangar doors.

Figure 5 shows two elevation views of the hangar and the orientation of the skylights. These skylights

have louvered glass openings which are electrically controlled for ventilation but which were closed for

all of the experiments.

The hangar bay is fully protected by open-head deluge sprinklers on a pipe scheduled system with a protection area per head of 9.3 m^ (100 ft^). The sprinklers are supplied by twelve independent deluge

valves which are activated by pneumatic heat actuated devices (HADs) located at the ceiling. The

pneumatic HADs operate according to a rate-of-rise principle such that when the temperature rise exceeds 7 °C to 8 °C per minute, air in the detector expands faster than it can be vented to the

atmosphere. At that point, a mechanical diaphragm in the pneumatic tubing converts the pressure to a
12 3 Warm Climate- 15 m Facility

mechanical action which activates a set of alarm contacts. The existing sprinklers and heat detectors were shut off during each of the fire tests.

There are no permanent draft curtains in the hangar. A temporary draft curtain made of fire retardant canvas was constructed and installed for six tests to evaluate the effect of the curtain on the activation

times. The space between the top edge of the draft curtain and the metal deck was sealed with

fiberglass insulation to prevent smoke leakage beyond the top of the curtain. The draft curtain was

installed centered over the fire area as shown in Figure 4. However, the fire, itself was not centered

within the hangar. The draft curtain area measured 24.4 m (80 ft) in length, 18.3 m (60 ft) in width,

and 3.7 m (12 ft) deep. The ceiling height at the west edge of the draft curtain was 14.2 m (46.6 ft).

3.1.2 Measurements - Fire Protection Devices

A number of conventional fire detection and suppression devices were installed and monitored to determine their actual response characteristics when subjected to the experimental fires. The fire suppression devices were all standard spray upright sprinklers with a variety of temperature ratings,

actuation mechanisms, and response time indexes.

The fire detection devices consisted of photoelectric smoke detectors, fixed temperature heat detectors,

projected beam smoke detectors, combination ultraviolet/infrared optical flame detectors and line-type

heat detectors.

3.1.2.1 Sprinkler Installations

In the 15 m high facility, nine types of standard spray upright sprinklers with a variety of temperature

ratings, fusible elements, and response time indexes were installed and monitored to measure the

activation time of each sprinkler head when subject to a range of experimental fires. The piping

supplying the sprinkler heads was filled with water to simulate the heat sink associated with a wet-pipe

sprinkler configuration. In addition, several sections of blank piping were used within the individual

sprinkler trees to simulate a dry-pipe or pre-action sprinkler system. This was done in order to compare the activation times of sprinklers on a wet-pipe system versus a dry-pipe or pre-action system.

The fires were designed to determine the threshold fire size for response of each sprinkler type. Each

type of sprinkler head listed in Table 4 was selected because of its existing use or potential use in high

bay applications.

Two parameters are used to rate sprinkler head sensitivity: activation temperature and response time

index (RTI). NFPA 16A [2] and NFPA 409 [17] currently require that the temperature rating of

sprinklers in hangars be within the "high" (79 to 107) °C or "extra high" 163 °C to 191 °C temperamre

range as defined by NFPA 13 [18]. Current Navy criteria require the use of sprinklers with a temperamre rating of 141 °C (286 °F) [19]. Ambient air temperatures at the ceiling level of aircraft

hangars can exceed 38 °C (100 °F). Therefore, the lowest temperature sprinkler that could be

reasonably installed in an aircraft hangar is a 79 °C sprinkler which corresponds to the low end of the

intermediate temperature range. (NFPA 13, Standard for the Installation of Sprinkler Systems, does

not permit the use of ordinary temperature sprinklers (i.e., 57 °C to 77 °C) in buildings where the

maximum ceiling temperature exceeds 38 °C.)

Figure 7(a) shows the location of each of the 15 sprinkler trees. Figure 6(b) shows the combination of
3 Warm Climate -15 m Facility 13

^

Runway Side ^ 73.8m ^

97.8m

Test Site

24.4m X 18.3m

24.4m

-JL

Sky Truss (TYP)

Light

Hangar

Door

Roof

Beams(TYP)

\Upper

Beams

Test North

Street Side

Figure 4. Plan view of hangar bay, 15 m high facility.
14 3 Warm Climate -15 m Facility

Figure 5. Photograph of ceiling structure, 15 m high facility.
3 Warm Climate -15 m Facility 15

^^18.3

3.7mA

m->-K 36.6m ^^^— 18.3m^

Sky Lights

te.1m>-

Cement Plaster

Glass

14.9nn

Steel Sash Windows

Concrete Walls

| < >| <

12.2m ' 73.2m

14.9m

Steel Panels

Glcss

Steel Panels

Five section Hangar

> i < > |

' 12.2m '

Trusses

Door

Figure 6. Elevation view of 15 m high facility.
16 3 Warm Climate -15 m Facility

Table 4. Sprinkler types installed in 15 m high test area

Activation Activation Description Piping Response Time

Temperature

°C

Temperature

°F

Configuration Index, (RTI)^

m-s'''' 79 175 Quick Response Bulb Wet 35

79 175 Quick Response Bulb Dry 35

79

93

175

200

Standard Response Bulb

Quick Response Bulb

Wet

Wet

188

35

141 286 Quick Response Bulb Wet 35

141 286 Quick Response Bulb Dry 35

141 286 Standard Response Bulb Wet 188

141 286 Standard Response Link Wet 95

182 360 Standard Response Bulb Wet 188

^ NFPA 13 defines Response Time Index (RTI) as a measurable expression of the sensitivity, or responsiveness to temperature change, of the thermal sensing element of a sprinkler.

sprinkler types installed at each location. Each location contained a 141 °C quick response bulb and

79 °C quick response bulb. The 141 °C head satisfies current Navy criteria, and the 79 °C head

would provide the first sprinkler response. In addition, the sprinkler stations within 6.1 m of the plume

also contained a 141 °C standard response bulb and a 141 °C standard response link. These provide a point of comparison between standard and quick response sprinklers, and bulb versus link fusible

elements. In addition, sprinkler locations within 3.1 m of the plume also contained a 141 °C quick

response bulb and a 79 °C quick response bulb piped dry. This provides a point of comparison

between similar sprinkler types on a wet-pipe or dry-pipe/pre-action configuration. The sprinkler

station located over the center of the plume also contained a 79 °C standard bulb and 182 °C standard

bulb. The 79 °C standard bulb provided a comparison with the quick response bulb of the same

temperature rating. The 182 °C head was provided because NFPA 409 requires it for some hangars.

The sprinkler deflectors were installed approximately 300 mm to 360 mm below the ceiling deck.

NFPA 13 states that under obstructed construction, the sprinkler deflector shall be located 25.4 mm to 152 mm (1 in. to 6 in.) below the structural members and a maxunum distance of 559 mm (22 in.)

below the ceiling/roof deck. Ball valves were installed on each riser nipple to isolate each sprinkler

tree in order to prevent head pressure effects from sprinkler assemblies at higher elevations, and to make the filling process more efficient.

Individual sprinkler heads were installed on the sprinkler trees using 1 inch tee fittings. Each sprinkler

tree represented the location of a single sprinkler head in a typical hangar installation. Because the

response of various sprinklers was being monitored at each sprinkler tree location, the spacing between

heads on each tree was limited to 203 mm (8 in). This minimum separation between sprinkler heads was needed to eliminate the risk of wetting adjacent heads after activation, thus affecting activation

times. The vent port also allowed any buildup of pressure to escape during the test. Although there was water in the sprinkler supply piping, the control valves were shut off to prevent water from being
3 Warm Climate -15 m Facility 17

discharged during the experiments.

The sprinkler piping was installed in accordance with NFPA 13 by a local sprinkler contractor. Cross

mains, which were hung from support beams parallel to the floor, consisted of 1 Vi inch schedule 40

galvanized pipe with a main drain/fill line attached to a central water supply in the hangar. From these

cross mains, riser nipples were installed to supply water to the individual sprinkler trees. A sprinkler

tree consisting of numerous sprinkler heads was attached to the top of each riser nipple. The riser

nipples were placed at 3 m intervals originating from the center of the test area as shown in Figure 8. Consequently, the spacing between sprinkler trees was roughly 3 m (9.3 ft). The spacing between

sprinkler trees was selected to simulate the spacing between sprinklers in a typical hangar installation.

Figure 9 shows a diagram of the typical valve and wiring connections for a sprinkler tree. A union

fitting was installed above the ball valve on each riser nipple to facilitate installation and removal of the

sprinkler trees. Each sprinkler tree included a vent port to relieve pressure, and purge trapped air from

the line.

The time to activation for each sprinkler head was measured and recorded. Figure 9 shows the method

used in brief detail. A standard paper clip was inserted between the fusible element and the sprinkler arm. Wires were then attached to the clip and to a central grounding point on the sprinkler tree. All

sprinkler heads were monitored on four 16-bit digital I/O cards located inside the data acquisition

system. With the sprinkler's fusible element in place, electrical continuity was established, thus

appearing as a closed switch or logic "0" to the digital I/O board. Upon activation, the fusible element

would shatter or dislodge and the paper clip would pull away from the sprinkler, thus breaking the

circuit. This action was recorded when the logic bit for the sprinkler went to a high or logic "1" state.

It was important to make sure the clip would pull away completely from the sprinkler; therefore, small

weights were used to provide additional load to the clip/wire assembly. The 7 g weights were placed

approximately 150 mm (6 in.) behind the clip and the wire leads were fastened so the clip was allowed

to swing away and clear from any grounded object in the area.

The data collection rate for the sprinkler activation time measurement was approximately

0.25 Hz. Provided the clip/wire assembly activated freely, the time of activation was measured within

4 s to 8 s after actual activation. Each sprinkler head was visually inspected between tests to determine

if any activations occurred that were not recorded by the data acquisition system. All sprinkler heads

that activated were replaced between tests. Any sprinkler head that did not activate during the previous

tests was inspected and cleaned prior to the next test fire.

All sprinkler heads and piping assemblies were supplied and installed by the Viking Corporation on

behalf of the automatic sprinkler industry. NIST was responsible for the data collection and the

installation of the wiring used to monitor the activation of the sprinkler heads. In cases where the

activation of a sprinkler head was not recorded by the data collection system, representatives from

Viking Corporation reported any additional sprinkler activations based on visual inspection at the end

of each experiment.

3.1.2.2 Smoke and Heat Detector Installations

The instrumentation included photoelectric smoke detectors and electronic heat detectors connected to an addressable fire alarm control panel via signaling line circuits wired in the Style 4 configuration as
18 3 Warm Climate -15 m Facility

CO

od

h< 24.4 H

N2 (p8.5

N5CU.I

N10C |3.1

W3 W4 W5 W10 C E15 E10 E4 E3

11.6 9.1 6.1 3.1 S9(

S4C

S3 (

13.1

16.1

D8.5

6.1 —O—9.1 —

O

11.6

Draft Curtain

(a)

A B

AB

ABC

A B

CD

D E F

C D

A-14rC(286°F)QR Bulb B-79°C (175°F)QR Bulb C-14rC (286°F)STD Bulb D-14rC (286°F)STD Link E - 14rC (286°F) QR Bulb (dry) F-79°C(175''F)QR Bulb (dry) G-93°C (200°F)QR Bulb H-79X (175^)510 Bulb 1-182''C (360°F) STD Bulb

All Dimensions In Meters

E F G M

ABC

H I

DE F

A B C D

(b)

Figure 7. Individual sprinkler locations within 15 m high test area.
3 Warm Climate -15 m Facility 19

Roof Line, slope = .042 mm/m

Riser Nipples

Sprinkler Stations

11.6 9.1 6.1 3.0

24.4 (80 ft.)

6.1 9.1 11.6

Draft Curtain

JSl Union

Ball Valve

All dimensions are in meters

South

Perpindicular Pipe Section (see below)

Draft Curtain Northgg HjO Fill/Drain

Draft Curtain on 1 8.3 m side is 0.6 m beyond last sprinkler

Figure 8. Sprinkler locations within 15 m facility test area.
20 3 Warm Climate -15 m Facility

Detail of Wiring

for Activation Time

Measurement

Vent Port

Sprinl^ler Head

/ 203 mm >

Schedule 40, 25.4 mm (1 in.) Black Steel Pipe

Union

.4^-- Bail Valve

Figure 9. Diagram of typical sprinkler tree with activation time measurement.
3 Warm Climate -15 m Facility 21

defined in NFPA 72, National Fire Alarm Code [20]. The rate compensation heat detectors were

installed because they satisfy the Navy's existing criteria for hangar detection systems at the time these

experiments were conducted. Although photoelectric smoke detectors are typically not installed in aircraft hangars, they were installed in these tests to document their response time with respect to heat

detectors and projected beam detectors, and to aid in the analysis of possible stratification effects.

The photoelectric smoke detectors were analog addressable spot type detectors which operate according

to the light scattering principle. These detectors contain a pulsed LED and silicone photodiode receiver

arranged so that light does not fall on the receiver. When smoke particles enter the light path, light

strikes the particles and is scattered onto the photosensitive receiver, causing the detector to respond.

The detector sends an analog value representative of smoke concentration to the fire alarm control

panel. Alarm conditions correspond to a predetermined threshold in the software algorithms. The

panel recognizes this threshold value and responds by going into alarm status. The sensitivity setting

selected for each smoke detector was 8.2 % per meter (2.5% per foot) of smoke obscuration.

The electronic heat detectors were analog addressable spot type detectors which were programmed to operate as fixed temperature heat detectors with an alarm threshold of 57.2 °C (135 °F). Although this type of detector is also capable of operating as a combination rate-of-rise/fixed temperature detector,

each was programmed to operate only as a fixed temperature device. Because this type of detector

employs a non-metallic thermistor, it experiences little thermal lag and satisfies the UL 268

requirements for listing as a rate compensation heat detector [21]. A rate compensation detector is a device that responds when the temperature of the surrounding air reaches a predetermined level,

regardless of the rate of temperature rise. The sensor sends an analog value (in a digital

communications format) to the fire alarm control panel where the software algorithms are applied.

When the analog value received from a particular detector corresponds to a predetermined alarm

threshold, the fire alarm panel responds by going into alarm status.

There were 18 detector stations each consisting of a smoke detector and a heat detector mounted to a plywood board. The plywood board was suspended from conduit which was clamped to the underside

of the I beams supporting the metal roof deck. Given that the ratio of the beam depth to ceiling height was less than 0. 1, and that the ratio of the beam spacing to the ceiling height was less than 0.4, the

detectors were installed at the same elevation as the bottom of the beams which was 0.25 m (10 in)

below the ceiling deck. The location of the detector stations with respect to the fire plume is shown in Figure 10. The heat and smoke detectors at detector station number 14 did not respond during any of

the experiments because they could not be mounted at the ceiling level due to the configuration of the

skylight. NFPA 72 [20] offers little guidance on the spacing of spot type detection devices in buildings

of this height. However, NFPA 72, Table 5-2.7.1.2 indicates that the spacing of heat detectors for

ceiling heights up to 9. 14 m (30 ft) should be reduced to 34% of their listed spacing. Using that as a general guideline, the spacing of detector stations was reduced to 3.0 m (10 ft). The detectors were

only installed along the north/south and east/west axes with respect to the center line of the fire plume.

Where a proposed detector location occurred directly at the intersection of the draft curtain and the

ceiling, that detector station was installed 0.6 m (2 ft) within the draft curtain boundary. In addition,

for each compass direction, one detector station was located 1.5 m (5 ft) outside of the draft curtain.

Installation, calibration and test data from the smoke and heat detectors were provided by Simplex

Time Recorder Co., on behalf of the detector industry. Data were collected at the addressable fire alarm control panel at a scan rate of approximately 1 Hz.
22 3 Warm Climate -15 m Facility

(Not

Installed)

H14

P14

10.7 m

Test North -<

H13

P13

8.5 m

H10

P10

13.7 m

H9

P9

11.6m

H8

PS

9.1 m

H7

P7

6.1 m

H6

P6

3.0 m

H16

P16

6.1 m

H17

P17

8.5 m

(28 ft) Source

H12

P12

6.1 m

H11

P11

3.0 m HI

P1

3.0 m

H15

P15

3.0 m

(10 ft)

H2

P2

6.1 m (20 ft)

H3

P3

9.1 m (30 ft) H4

P4

11.6m (38 ft)

H18

P18

10.7 m

(35 ft)

Draft Curtain

H5

P5

13.7m (45 ft) H = Heat Detector

P =|Photoelectric Detector

All distances are from center (Source)

Figure 10. Heat and smoke detector locations, plan view, 15m high facility.
3 Warm Climate -15 m Facility 23

3.1.2.3 Projected Beam Smoke Detector Installations

Projected beam smoke detection systems are photoelectric smoke detectors that consist of separate

transmitters and receivers. The transmitter and receiver may be separated by up to 91 m (300 ft.), as long as they retain linear alignment. The light source in the transmitter produces an invisible infrared

beam that is measured by the receiver to determine obscuration caused by smoke. If the beam intensity

falls below an alarm threshold and remains there for preset length of time, a fire alarm is initiated. If complete beam blockage occurs, a trouble output is generated rather than a fire alarm. The receiver

will wait a preset length of time after the beam is blocked before signaling a trouble. This prevents

moving objects (i.e., cranes, lifts, etc.) from causing trouble signals. Gradual loss of signal due to dust/dirt build-up and other long-term effects is automatically compensated for by the receiver up to a point where the signal has been reduced by 50 %. When 50 % of the signal is lost, the receiver will

indicate a trouble [22]

.

The sensitivity is set at the receiver. The setting choices are between 2 and 7 representing a 20 % to 70 % decrease in signal strength. As distance increases, less dense smoke is required to obscure the same percentage of signal. UL268 Standard for Safety, "Smoke Detectors For Fire Protective

Signaling Systems," specifies that a projected beam smoke detector shall not activate with less than

0.65 % per meter (0.2 % per foot) obscuration of its light beam [21]. This represents the maximum

sensitivity setting (the least amount of smoke that will activate the detector). UL268 also specifies

minhnum sensitivities as a function of distance (the most amount of smoke that can be present before

the detector activates). UL268 states the detector shall activate when the light it transmits through clear

air is obscured by smoke by the following amounts:

a. equal to 6.5 % per meter (2 % per foot) of length of its light beam for lengths of 6.7 m (22

ft) or less; b. not more than 36 % total obscuration of its light beam for lengths of 6.7 m to 13.4 m (22 ft to 44 ft); or

c. equal to 3.3 % per meter (1 % per foot) of its light beam for lengths of more than 13.4 m

(44 ft).

The relationship between the percent obscuration per meter (OJ, the attenuation of the light beam due

to obscuration (Tj/T;.), and the distance between the transmitter and the receiver can be calculated using

the following formula:

0„ = [1 - ( —)'] X 100

where: T^ — transmission in smoke (signal strength in volts)

Tj = transmission in clean air (signal strength in volts)

d = distance between transmitter and receiver (m)

Adapted from UL268, Figure 11 compares the distance between transmitter and receiver and smoke

densities per unit length. The family of curves is generated by solving for O^ for a range of detector

sensitivities from 20 % to 70 % and separation distances from 10 m to 100 m. The horizontal lines

shown in this figure are the U.L. specified maximum and minimum allowable sensitivity thresholds for

this type of detector. For example, at a 40 % sensitivity setting, T^/T, = 0.6. Given a separation
24 3 Warm Climate -15 m Facility

12

10

P 8

^ 6 w

c

0) Q^ 4

E

UL Minimum Sensitivity

Q _ UL Maximum Sensitivity T T T T

10 20 30 40 50 60 70 80

Distance Between Transmitter and Receiver (m)

90 100

Figure 11. Smoke density as it relates to detector/transmitter separation distance.

distance of 40 m, the resulting smoke density needed to produce an alarm condition is 1.3 % per meter.

One logic feature of the projected beam detectors is a "window." The window is the time the signal

must remain below the preset sensitivity level before an alarm is generated. At present the U.L.

approved window is 30 seconds (this is based on ordinary combustible fire loads and not jet fuels).

This setting requires the detector signal to drop below the preset threshold for 30 seconds without

exceeding 90 % signal loss before an alarm can be generated. The window for a trouble alarm is 20

seconds. If the signal loss is greater than 90 % for more than 20 seconds, a trouble condition will be

generated. For some of the experiments conducted in the 15 m facility, the fire alarm window setting was decreased to 5 seconds. This setting was used to determine the difference in response of the

optical beam detectors with a shorter window time. However, this window setting is not currently

U.L. approved. Sensitivity and window settings for each experiment are specified in Table 5.

Because the slope of the 15 m high ceiling was not greater than 0. 125, the ceiling was treated as a flat ceiling [20]. The projected beam detectors ran perpendicular to the 0.25 m (10 in) deep I-beams

supporting the roof. These detectors have a listed spacing of 18.3 m (60 ft). In addition, the
3 Warm Climate -15 m Facility 25

manufacturer's guidelines recommend a minimum separation distance between transmitter and receiver

of9.1m(30ft).

A total of nine projected beam smoke detectors were installed in the 15 m facility as shown in Figure

12. Detectors were installed at three elevations, 0.3 m (1 ft), 2.7 m (9 ft), and 5.8 m (19 ft) below the

ceiling with their beams directed parallel to the ceiling. The 0.3 m and 2.7 m elevations were above the

bottom of the draft curtain. The 5.8 m elevation was below the level of the draft curtain which had a depth of 3.7 m (12 ft). Three detectors were installed at each elevation, and were spaced 7.0 m (23 ft) apart, with 2.1 m (7 ft) clearance from the north and south draft curtain boundaries. Figure 13 shows

the detector locations within the overall plan view of the hangar. For tests 1 through 8, the projected

beam detectors spanned the length of the draft curtain which was 24.4 m (80 ft). Because the light

beam widens as the distance between the transmitter and receiver is increased, the transmitters and

receivers were staggered on adjacent levels so the signals would not interfere with each other. This

installation was in accordance with NFPA 72 [20] and the manufacturer's installation requirements

[23]. All detectors were wired in a style A configuration as defined in NFPA 72.

For tests 9 through 13, the lower row of beam detectors were relocated. These tests were all conducted without the draft curtain in place. A transmitter (T7) was installed on the far east wall of the

aircraft hangar. The three receivers (R7, R8, R9) were relocated to the center of the far west wall of

the hangar. The distance between the transmitter and receivers was 97.8 m (321 ft). The transmitter's

signal (T7) was wide enough at this distance to be received by all three receivers which were mounted

adjacent to each other. The transmitter and associated receivers were installed 1.8 m (6 ft) below the

ceiling. The receivers were all set at a sensitivity of 50 %; however, the window settings for R7, R8

and R9 were 30 s, 10 s and 5 s respectively.

Installation, calibration, and test data were provided to NIST by Detection Systems Inc., on behalf of

the smoke detector industry. The detectors were hard-wired to the direct zones on the Simplex fire alarm control panel, and wired in the Class B, Style B format as defined by NFPA 72. Data were

collected through the Simplex fire alarm panel at a scan rate of less than 1 Hz. Also, the analog data

from each detector were recorded on a data logging system provided by Detection Systems Inc. The

scan rate in this case was approximately 1.25 Hz. The lenses of all the detectors were cleaned after test number six. In all other cases, the beam detectors reset themselves [24].

3.1.2.4 Combination UV/IR Optical Flame Detectors

Optical flame detectors are used in aircraft hangars to provide prompt detection of a jet fuel fire which

may be located beneath the wing of an aircraft. UV/IR detectors are generally mounted just below the

wing height of the smallest aircraft in the hangar. This height usually corresponds to 1.8 m to 3.7 m

above the floor. Combination UV/IR detectors are the most prominent optical detectors used in aircraft

hangars because of their ability to quickly respond to a flaming fire. The ability to avert false alarms

give the combination UV/IR detectors an advantage over individual UV and IR optical detectors. For

example, individual UV detectors are subject to false alarms from arc welding and lightning.

Individual IR detectors are subject to false alarms from hot body radiation such as a hot engine. In this type of combination detector, both the UV and IR detector heads must independently go into alarm

before a fire alarm signal is initiated. However, combination detectors can be blinded. Oil and dirt will

blind UV detectors, while ice, water films, and certain vapors blind IR detectors.
26 3 Warm Climate -15 m Facility

Table 5. Sensitivity and window settings for projected beam smoke detectors

Test No. Projected Receiver/ Sensitivity Window Settings (s) Beam # Transmitter Pair (% signal loss)

1-4 Bl Rl/Tl 30 30

B3

KZ/ 1 Z

R3/T3 30 30

B4

,.,-,...... .,...,,.:...,....^^^^^ 30 30

B5 R5/T5 30 30

B6 R6/T6 30

30

30

B7 R7/T7 30

RSDO R8/T8 30 -^:^-^^::^''l:^il 30

B9 R9/T9 30 30

5-8 Bl Rl/Tl 30 30

B2 R2/T2 30 30

B3.^ ._,.^ B4|||||||;R3/T3

R4/T4 20

30

5

B5 R5/T5 ,.;.,..^,2o':-f-ilfi 5 B6 R6/T6 20 5

:.:.::...:.:.:.:.:-:.:.:.:.:.:.p,:.:.:.:.:.:.: :.:.:.:,-:.:.:-: ''"""""""" R7/T7

""^^"^""^'^^ .,:.:,:.:,:,..::^^:,:.:.:.,.:.:,:.:.:.:.:.:.:.,.:,:.:.:...: 30

B8 R8/T8 30 30

B9 R9/T9 30 'm^v^m :;v;::|:ll|:i|;;Ksi-:

9-13 Bl Rl/Tl 30 30

B2 R2/T2 . :mm::mMmmi,m::: 30 .,,:, B3 R3/T3 30 30

B4 R4/T4 WSKKSiim

,,.•„ ^

B5 R5/T5 20 5

B6 R6/T6 20 5

B7 R7/T7 50 30

B8 R8/T7 50,^^^ 10

B9 R9/T7 50 5
3 Warm Climate -15 m Facility 27

Configuration for tests 1-8 Test North

0.3m

Figure 12. Locations of projected beam smoke detectors, 15 m high facility.
28 3 Warm Climate -15 m Facility

hRunway Side ^ 73.8nn

~tr

97.8m

T7

30.5m

Draft

Curtain

Main Support

Column

Hangar

Door

R7 R8 R9

48.8m

Test

Center

Point

Test North

Street Side

Figure 13. Plan view of projected beam smoke detectors, 15 m high facility.
3 Warm Climate- 15 m Facility 29

The UV portion of the combination detector utiUzes an ultraviolet (Geiger-Muller) flame detector tube.

The UV sensor responds to high energy radiation with wavelengths from 0.185 to 0.245 fim.

Ultraviolet radiation from the flame strikes the cathode of the gas-filled sensor tube, and a discharge of

electrons is initiated towards the anode. The flow of current induced by the radiation creates a charge/discharge action through a series RC circuit, thus producing electrical pulses at the output. The more intense the incoming radiation, the higher the pulse rate. The tube discharge or pulse rate is measured in counts per second (CPS). The CPS output is compared to a preset alarm threshold, and if exceeded, a UV fire alarm output is initiated.

The IR portion of the detector utilizes a single frequency infrared flame detector. Infrared radiation

from the fire is transmitted through optical filters that allow only 4.4 jum energy to pass. The filtered infrared radiation is detected by a pyroelectric infrared sensor. The sensor converts the filtered infrared energy to a DC millivolt signal. Modulation or flicker of the DC signal is required in order

for further signal processing to occur [25]. Like the UV portion of the detector, the pulse rate is measured in CPS which will produce an IR fire alarm at the controller once the CPS exceeds a preset

alarm threshold. To compensate for the quiescent output level of the IR detector, the controller

subtracts 1 count from the IR input every 62.5 ms (i.e., 16 counts per second). The counts are never

allowed to be fall to a negative value.

The controller receives the electrical pulses (i.e., counts) from the UV and IR sensors and compares

those signals to the preset sensitivity to determine if a fire exists. The controller allows the user to set the thresholds for gate length, counts per gate, and number of consecutive gates required to initiate an

alarm. The "gate length" is the increment of time the controller looks at the detector signal to determine if the "counts per gate" requirement is fulfilled. The "counts per gate" are the actual

number of electrical pulses received from both the UV and IR sensors within the established gate

length. The "number of consecutive gates" is the number of gates which the controller must see the

actual counts per gate requirement fulfilled consecutively in order to recognize an alarm threshold.

These combination UV/IR detectors are also available in a unitized configuration. The unitized UV/IR

detectors only allow the user to change the response time of the detector between 0.5 seconds and 3

seconds. The choice of settings on the unitized detectors translates to either 0.125 s gate length, 2

counts per gate and 3 consecutive gates (i.e., roughly 0.5 s response time); or 0.125 s gate length, 2

counts per gate and 24 consecutive gates (i.e., 3 s response time). Controller-based detectors were

selected because they allow the user a greater degree of flexibility when setting the sensitivity of the

detectors.

Two settings chosen for the experimental fires: 0.25 s gate length, 2 counts per gate and 3 consecutive

gates; and 0.25 s gate length, 4 counts per gate and 4 consecutive gates. Table 6 shows the controller

settings for each experiment. Each UV/IR detector was scanned at a rate of 10 Hz. Although

combination detectors were used, the analog CPS data were collected for each UV and IR detector

head independently. Consequently, an analysis of the CPS data will show when each UV or IR head

individually reached its alarm threshold. These data can also be analyzed to predict the response of

unitized-based detectors, or controller-based detectors with different settings.

For these experiments, each UV/IR detector was installed at a mounting height of 2.4 m (8 ft) above

the floor which is a typical mounting height for hangars which house fighter aircraft. The ten UV/IR

detectors were mounted on portable stands which were located radially out from the fire. Each
30 3 Warm Climate -15 m Facility

Table 6. Controller settings of combination UV/IR detectors with respect to test number

Test Number Description

(Pan Size)

Controller Settings

Gate Length

(s)

Counts per

Gate

Consecutive

Gates

1

2

3

4

5

6b

7

8

11

12

13

0.3 m X 0.3 m

0.6 mx 0.6 m

0.9 mx 0.9 m

1.5 m Diameter

2.0 m Diameter

2.5m Diameter

2.0m Diameter

2.5m Diameter

0.3 m x 0.3 m

0.6 mx 0.6 m

2.0 m Diameter

0.25

0.25

0.25

0.25

0.25

0.25

0.25

0.25

0.25

0.25

0.25

2

2

2

2

2

2

4

4

2

2

4

3

3

3

3

3

3

4

4

3

3

4

detector was placed to provide a direct line of sight to the fire. Distances from the detectors to the fire were measured along this line of sight as shown in Figure 14 which is an example of the detector layout

for the sprinkler fires. The detectors were aimed at the center of the pan using a visible HeNe laser.

Detector locations varied with the fire pan size; however, for all experiments conducted there were

detectors placed at distances of 21.3 m, 30.5 m, and 48.8 m from the fire. All distances were measured

along the floor from the detector to the center of the pan. Detector locations for all experiments are given in Table 7. For the sprinkler fires, (i.e., the 1.5 m, 2.0 m, and 2.5 m diameter pans), additional

detectors were placed at 6. 1 m intervals from 36.6 m through 67. 1 m and also at 64.0 m and 70. 1 m.

For the detector fires, (i.e., the 0.3 m x 0.3 m, 0.6 m x 0.6 m, and 0.9 m x 0.9 m square pans), the

distance the detectors were placed from the fire varied with fire pan size. In all three cases, the

maximum distance a detector was placed from the fire was 48.8 m. For the first 0.3 m x 0.3 m square

pan fire (i.e., test 1), additional detectors were placed at 1.52 m intervals from 9.1 m through 18.3 m

from the fire. For the first 0.6 m x 0.6 m and the 0.9 m x 0.9 m square pan fires (i.e., tests 2 and 3),

additional detectors were placed at 1.52 m intervals from 21.3 m through 27.4 m, and at 3.0 m

intervals from 30.5 m through 39.6 m. For the second 0.3 m x 0.3 m and 0.6 m x 0.6 m square pan

fires (i.e., tests 11 and 12) additional detectors were placed at 3.0 m intervals from 12.2 m to 30.5 m

and at 6.1 m intervals from 30.5 m to 48.8 m.

Ten controller-based combination ultraviolet/infrared (UV/IR) optical flame detectors were installed
3 Warm Climate -15 m Facility 31

Test and Fire Pan Center Point

048.8 m

©54.9 m. ©61.0 m

©64.0 m

©67.1 m

©70.1 m

21.3m© —

30.5 m©

36.6 m©

42.7 m ©

© UV/ IR Detector

Figure 14. UV/IR detector locations within test area, 15 m high facility
32 3 Warm Climate -15 m Facility

Table 7. Distances of UV/IR detectors (m) from test fires with respect to test number

Test# Pan Size Detector Number : :'xS:;: (m) 1

Detector Fires 1 2 3 4 5

• 6 7 8 9 10

1 0.3x0.3 9.1 10.7 12.2 13.7 15.2 16.8 18.3 21.3 30.5 48.8

2,3 0.6x0.6,

0.9x0.9

21.3 22.9 24.4 25.9 27.4 30.5 33.5 36.6 39.6 48.8

11 0.3x0.3 12.2 15.2 18.3 21.3 24.4 27.4 30.5 36.6 42.7 48 8

12 0.6x0.6 21.3 30.5 36.6 42.7 48.8 24.4 12.2 27.4 15.2 18.3

Sprimkler Fires 1 2 3 4 5 6 7 8 9 10

4,5,6b 1.5,2.0, 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

7,8,13 2.5 dia.

Ceramic Thermistor Core

/

Inconel Sheath

Center Conductor

Figure 15. Alison 9090-13 thermal sensor.

and monitored during each experiment. Installation, calibration and test data from the UV/IR detectors were provided by Detector Electronics Corporation on behalf of the optical detector industry.

3.1.2.5 Line-Type Heat Detector Installation

A line type heat detector provided by Alison Control Inc. was used to monitor the perimeter of the

draft curtain area in the 15 m high facility. The Alison 9090-13 continuous linear thermal sensor is small diameter coaxial wire capable of sensing temperature changes along its entire length. The sensor

is constructed with a center conductor and an outer Inconel 625 sheath. The center conductor is insulated from the outer sheath by a ceramic thermistor material as shown in Figure 15. The sensor

has a diameter of approximately 2.16 mm (0.085 in.) and therefore has a small mass which allows it rapidly to sense changes in temperature. Its response time index (RTI) is 58 [26] and its operating

temperature range extends from -46 °C to 1093 °C. Fire detection utilizing this sensor is accomplished
3 Warm Climate -15 m Facility 33

by measuring the resistance between the center conductor and the outer Inconel sheath. Since the

thermistor has a negative coefficient of resistance, electrical resistance between the center wire and the outer sheath decreases exponentially as the surrounding temperature increases. The resistance

characteristic of this sensor is equivalent to a parallel resistor network with an infinite number of

points.

Alison Sensor

Sensor Terminator

Terminal Box

Draft Curtain

^^^^X

1

I

1 6.1

^ 1

I ^ ^ ^ ^ ^ -J^-J' 1

1 6.1

J

24.4

18.3

3.1

Figure 16. Location of thermal sensor within 15 m test area.

Based on the fact that NFPA 72 does not specify placement of line type electrical conductivity detectors

in spaces greater than 9.1m (30 ft.) [20], the manufacturer was consulted to determine proper

placement. The Alison 9090-13 thermal sensor was installed in a "U" shaped configuration within the

test area. The sensor was located 6.1 m (20 ft.) from the north and south draft curtains as shown in

Figure 16. The sensor consisted of four 15.2 m (50 ft.) sections. Using beam mounted hangers

provided by the manufacturer, the sensor was hung approximately 0.3 m (12 in.) below the strucmral

steel beams.

In order to interface the sensor wire to NIST's data system, the junction box at one end of the sensor

cable was connected via instrumentation wire to a control module. The control module provided an

output voltage signal relating the temperature of the sensor at any given moment. The control module

output voltage was collected at approximately 0.25 Hz. Temperature of the sensor was obtained by

applying the manufacturer's response curve similar to Figure 17.

3.1.3 Measurements - Instrumentation

NIST installed and monitored 144 transducers during these fire tests. Sixty four measurements were of

sprinkler activation time as described above. Other transducers and instrumentation included

thermocouples, mass loss of burning fuel, mass flow of the ceiling jet structure, internal and external

wind speed and direction, and heat flux radiometers. In addition, video footage was recorded at several locations for visualization and analysis purposes.
34 3 Warm Climate -15 m Facility

• Temp, vs Signal 300 -

3'" Order Regression

250 - \

200 - \.

150 - \.

100 - \_^

50 -

-0.01 0.1 1 Output Signal (Volts)

10

Figure 17. Typical response curve for Alison 9090-13 thermal sensor.

Thermocouples

Temperatures were measured of the fire plume, air and fuel at 64 locations as shown in Figure 18. Bead-welded, exposed 0.3 mm diameter wire, type K thermocouples were used to measure these

temperatures.

To measure plume centerline temperatures and plume symmetry, sixteen temperature

measurements were taken over the fire plume. An array of five thermocouples was placed at 0.31 m

below the ceiling, one in the center over the fire pan, and one 1.5 m radially out from the center in

each of the four directions. Nine thermocouples were installed 3.0 m below the ceiling in a cross

pattern, one along the centerline, and two radially out from the center in each direction, at 0.91 m, and

2.1 m. These aided in determining which direction the plume was leaning. Two additional

thermocouples were installed at 1.5 m and 6.1 m below the ceiling along the centerline.

To measure ceiling jet temperature, thermocouples were placed in all four directions, 0.31 m below

the ceiling at 1.5 m, 3.0 m, 6.1 m, 9.1 m, and 11.6 m radially out from the center to the east and west,

and at 3. Om, 6.1m, 8.5m radially out from the center to the north and south. Also, in each of the

four directions, at 6.1 m radially out from the center, additional thermocouples were placed vertically

down from the ceiling to measure the temperature of the ceiling jet as a function of depth below the

ceiling. These were placed at 0. 15 m, 0.46 m, 0.61 m, and 0.76 m below the ceiling. This information
3 Warm Climate -15 m Facility 35

O Sprinkler Tree Location w\TC

X Thermocouple Only

Water Cooled Radiometer ^ Mass Flow Device

Skylight/Monitor

R3@1.22m off floor

All Dimensions in Meters

Figure 18. Instrumentation locations in 15 m high facility.
36 3 Warm Climate- 15 m Facility

is useful for fire model verification and for refinement of detector placement strategies.

To track the build-up of fire products within the draft curtained area, thermocouples were placed

at 8.5 m north, and 9. 1 m east of the centerhne. Thermocouples were installed from 0. 15 m to 3.0 m

below the ceiling. Assuming that the smoke and heat flow together, the thermocouple readings can

indicate the initial arrival of smoke to the thermocouple location.

To track the flow of fire products into the adjacent draft curtained areas, thermocouples were

installed outside of the draft curtained area in all four directions. Thermocouples were installed to the

north 11.6 m from the centerline (inside the skylight), to the south 11.6 m and 14.6 m from centerline,

and to the east and west 14.6 m and 17.7 m from the centerline.

To measure the temperature at time of activation of smoke and heat detectors, a thermocouple was

placed at each sprinkler tree/smoke detector station. These data provides information useful in model

verification and prediction of activation of fire protection devices.

To provide critical safety temperatures, a thermocouple was placed on the main structural steel beam

directly over the fire. Two thermocouples were placed within the fire pan (to monitor fuel depth and

pan temperature).

Mass Loss of Burning Fuel

Measurement of the mass loss rate of the burning fuel was essential for determining heat release values

for each test fire. This measurement also provided information on the time required for the fire to reach steady state condition. Heat release rates were estimated for all experimental fires for which

mass loss data were collected. The heat release rate (kW) was calculated by multiplying the mass loss

rate by the known heat of combustion for each fuel.

Since a load measuring platform had to accommodate pan sizes from 0.3 m square to 2.5 m diameter

round, it was necessary to build two separate platforms for this test series. Figure 18 describes the load

platforms. The smaller load platform used one 227 kg (500 lb.) strain gauge type precision load cell,

produced by GSE Inc. Measurements and Controls*. Coupled with a strain gauge power supply/

indicator, a voltage output directly proportional to total mass (kg) was produced. For the three point

load platform, three 454 kg (1000 lb.) strain gauges were connected in parallel to the power supply/

indicator. This configuration provided a 1361 kg (3000 lb.), in terms of total mass, capacity for the

load platform. The power supply/indicator device supplied a stable 10 VDC (0.005 %/°C stability)

excitation voltage to the 350 Q strain gauges. Depending on the gain factor programmed into the

indicator circuitry, standard units were displayed continuously and an analog output ranging from ±10

VDC was measured and logged through the data acquisition system. In addition the power supply/

indicator unit contained circuitry for calibration span adjustment and zero.

* Certain trade names and company products are mentioned in the text or identified in an illustration in order to specify adequately the experimental procedure and equipment used. In no case does such

identification imply recommendation or endorsement by the National Institute of Standards and

Technology, nor does it imply that the products are necessarily the best available for the purpose.
3 Warm Climate -15 m Facility 37

50.8 X 50.8 mm Aluminum Tube

Welded Supports

12.7 mm x .38 m dia. Aluminum Plate

12.7 mm x 0.203 m dia. Aluminum Plate

Welded Supports

Model 5353 454 kg

(1000 lb.) Strain Gauge

12.7 mm Calcium Silicate Board

12.7 mm bolts thru

Three Point Load Platform

12.7 mm Calcium Silicate Board Model 5353, 227 kg

(500 lb.) Strain Gauge

12.7 mm thick Aluminum Plate

Single Point Load Platform

Figure 19. Single and three point load platform schematic.
38 3 Warm Climate -15 m Facility

Calibrations were performed on both load platforms prior to fire testing. The single strain gauge load

platform was calibrated using a 18 000 kg (40 000 lb.) hydraulic testing machine. Approximately ten

points from (0 to 227) kg were recorded, along with the corresponding voltage output. For the three

point load platform a 1.5 m round pan, of a known volume, was filled with water to several depths and

the corresponding voltage was recorded. By calculating the mass of water for each volume, a

calibration constant was obtained for several points. In addition, an experiment was performed using a small electric pump to discharge the water, thus simulating the mass loss characteristics of a pan of

V)

(0o

V)TO

^

Test 1 Mass.^., = 297.3 i Test 2 Mass.^.^= 303.21.513 Volts

1.542 Volts

J I

I I _J I ,

I I I L_ _J II I I I ,I I I L. 200 400 600 800 1000 1200 1400

Time (sec)

Figure 20. Results from sample mass loss simulation experiment.

burning fuel. Two similar runs are shown in Figure 20. Each strain gauge was thermally protected

using a ceramic blanket wrapped loosely around the gauge and the load platform frame was protected

using 12.7 mm (0.5 in.) calcium silicate board. The uncertainty of the mass measurement for the load

platforms is a function of the uncertainty of the strain gauges, power supply indicator, and the data

collection system. The manufacturers of the strain gauges indicate a non-repeatability of ^0.01 % with

a temperature effect rating on output of +0.002%/°C and a stability of excitation voltage of

0.005 %/°C. For the power supply/indicator, the manufacturer reports an accuracy with respect to temperature of 0.005 %/°C. Overall, excluding the uncertainty of the data collection system (discussed

in following section), the uncertainty of this measurement depends on the temperature stability of the

individual components, primarily. With this in mind, a conservative estimate of ±0.5 kg variation can
3 Warm Climate -15 m Facility 39

be assumed.

Ceiling Jet Velocity Transducers

Ceiling jet velocity measurements were made using two Sierra Steel-Trak Industrial Insertion Mass

Flow Meters (series 640). Locations of these mass flow meters are indicated in Figure 18. V, in the

figure is located 6.1m (20 ft.) in the east direction and is positioned at nearly the same elevation (0.3

m below ceiling deck) as the thermal element of the sprinkler at station ElO. V2 is located at 6. 1 m in

the north direction and at a similar elevation. The rationale for choosing these locations was to investigate the mass flow of the ceiling jet in the vicinity of a sprinkler. From this measurement,

information about the convective cooling of the sprinkler's thermal element could be realized.

The transducer contains two sensors; a velocity sensor and a temperature sensor that automatically

correct for temperature changes. Both sensors are reference-grade platinum RTD's wound on a ceramic mandrels. Internal circuitry heats the velocity sensor above ambient with respect to the

temperature sensor and measures the cooling effect of the gas flow. Since the heat is carried away by

the gas, the heated sensor directly measures gas mass velocity, pV, referenced to standard conditions of

21.1 °C (70 °F) and atmospheric pressure. Electronically, an output voltage signal (0 to 5)VDC is produced which is proportional to the total gas mass velocity. The usable range for these transducers is up to 0.5 m/s (100 ft/min) at standard conditions.

Wind Speed and Direction Meters

Wind speed and direction were measured inside and outside the hangar during the experiments. The

objective of this measurement was primarily to observe the effects of wind currents occurring during an open door experiment. Four wind speed/direction meters were used. One meter was mounted on the

roof of the hangar to observe ambient wind conditions. This measurement was augmented by the

weather station at NAS Barbers Point which provided updated weather data collected at various points near the hangar. The other three meters were placed in a straight line, approximately 3.0 m (10 ft.) above the floor, generally upwind from the fuel pan (open door case). The distance from the center of

the fuel pan to the wind speed/direction meters varied. Table 8 lists the distances with respect to test number.

Table 8. Distance from wind speed meters to center of fuel pan. „ „ „ . _ . . . Distance From Center ot J^uei Fan to wmd Meter (m)

Test Number 1 2 3

1 25.9 (85 ft.) 15.2 (50 ft.) 6.1 (20 ft.)

4 25.9 (85 ft.) 18.3 (60 ft.) 11.3 (37 ft.)

9 25.9 (85 ft.) 18.3 (60 ft.) 10.7 (35 ft.)

The wind speed meters use a 3-cup anemometer to produce a time varying pulse where the frequency

of the pulse is proportional to the wind velocity. For example, 1 pps equals 0.45 m/s (1 mph). Since
40 3 Warm Climate -15 m Facility

the data system could not capture signals of this frequency, a frequency to voltage converter was

constructed which produced a voltage proportional to wind speed. Using the manufacturer's calibration constant for the meter, a calibration curve was established by using a constant speed fan and a calibrated strobe light configuration. The wind direction was indicated by the change of resistance

measured across a center tapped, single-turn potentiometer located inside the turret of the wind

direction vane. With a constant voltage applied to the potentiometer, the potential at the center tap

varied with change in direction. The "north" direction was established by orienting the meter so that the voltage output was near zero. Typically, the DC voltage range for a complete 360° turn of the vane was from V to 9 V which corresponds to a change of 26 mV/degree. Ten angular degrees were

subtracted during each revolution due to account for the "dead band" of the potentiometer.

The primary degree of uncertainty for the wind speed/direction meters originates in the conversion of

frequency to voltage for wind speed. Since the conversion is accomplished by utilizing an RC charge

pump method, there is considerable ripple effects at the lower frequencies. Ripple, caused by the

charge/discharge action of a capacitor in the circuit, yields a variance of nearly 10% in the 0.95 m/s to 6.7 m/s wind speed range. According to the manufacturer, wind speed, using a pulse counting

measurement, can be measured to within +0.15 m/s. Wind direction can accurately be measured to within ±2°. Mechanical wear and friction can also cause measurement errors. For example, the cup

anemometer must overcome a friction force associated with the internal bushing. Therefore, a threshold

velocity [typically 0.95 m/s (2.1 mph)] prevents the meter from reading small air currents that may

develop during a test.

Heat Flux Radiometers

Three water cooled, Gardon type heat flux transducers were used to measure total heat flux from the

test fires. Figure 18 indicates the location of the gauges. Two transducers (Rl and R2) were mounted

at 6. 1 m east and 0.15 m below the ceiling and 9.8 m off the floor, respectively. The third transducer

(R3) was placed 1.22 m off the floor but at several different distances away from the fire.

The Gardon type transducer absorbs heat flux in a thin metallic circular foil at the surface and then

heat is transferred radially out to an integral heat sink which remains at a temperature below that of the sensor surface. The difference in temperature is taken between the center and edge of the foil. This

temperature difference between the points along the path of the heat flow from the sensor to the heat

sink is proportional to the heat being transferred, and, therefore proportional to the heat being

absorbed. The transducer uses a thermocouple which generates a thermoelectric circuit providing a

self-generated EMF between the two output leads directly proportional to the heat transfer rate.

The nominal measurement range of the transducers was to 50 kW/m^ with a maximum operating

temperature of 204 °C (400 °F). The output voltage provided by the sensor was up to 10 mV with

over-range capability of 150% ( + 15 kW/m^). Other characteristics include maximum nonlinearity of

±2% full range, less than 0.05 s response time, measurement uncertainty of +3 % (0.3 mV), and

sensor absorptance of 0.92 from 0.6 /nm to 15.0 ycm.

Cooling water for these transducers was provided by the water main used for filling the sprinkler trees. Plastic hose (9.5 mm O.D.) was used to supply the transducers and provide a drain line which was

piped to a central drain in the hangar.
3 Warm Climate -15 m Facility 41

Data Acquisition System

The data acquisition system used to collect fire test data in the 15 m high facility was the Hewlett

Packard 75000 series B Data Acquisition/Control Unit (HP 1301 A Mainframe). This unit uses an

industry standard IEEE-488.2 command structure; complimented by the HPVEE graphical user

interface. The programming, logging, and analysis was done on an IBM compatible computer

operating under a 486-dx2 microprocessor, at a speed of 66 MHZ.

Analog and digital input signals were captured via various interface cards mounted within the

instrument rack of the 75000B. The entire system was protected with a 450 kV uninterruptable power

supply (UPS) and surge protector. In the event of a power failure, the system would remain on battery

power for 5 min to 7 min. Figure 21 describes the general components incorporated into the data

acquisition system The HP 1301 A contains an internal 5V2- digit multi meter (HP E1326B) which

measures the input voltage signals and then provides ASCII type data to the computer for storage and

manipulation. The multi-meter is capable of resolving 120 nV in the 0. 125 V range, and as stated by

Hewlett Packard, the accuracy over 90 days is 0.01 % . The input modules consisted of four 16-channel

type K thermocouple modules, two 32-bit digital input modules, and one 16-channel analog voltage

module.

Programming each component of the data acquisition system was accomplished using the HPVEE

graphical user interface (GUI). Real-time displays, channel conversions, and analysis functions were

all part of the GUI. These features were quite useful in observing temperatures at various locations, mass loss with respect to time, and important safety factors during the fire tests.

Other Measurements and Information

In addition to measurements described above, video footage of each test fire was taken. In all cases, High resolution 8 mm video cameras were located in three specific areas with respect to the test fire. Camera 1 was approximately 13.4 m (44 ft.) from the center of the test fire, looking in the direction of

the north wall. This angle provided a view of the fire pan, hangar door, windows, and other large

objects from which visible flame height could be estimated. Cameras 2 and 3 were located in the eastern and north western sector of the hangar bay, respectively. The locations of cameras 1 and 2

complimented one another by supplying information on time to full pan involvement, flame propagation

across fuel pan, flame structure, and symmetry of the plume. Camera 3 focused on the top of the

hangar to observe smoke filling rates and relative obscuration.

Weather data, measured at several locations in the vicinity of the hangar, was provided by the weather

station at NAS Barbers Point. Temperature, relative humidity, wind speed/direction, dew-point,

barometric pressure, and precipitation amounts, were reported hourly.

3.2 Test Fires, 15 m High Facility

Thirteen fire experiments were conducted in the 15 m high facility. Eleven of these were pool fires burning JP-5 jet fuel. The jet fuel fires ranged in size from 0.09 m^ (1 ft^) to 4.9 m^ (52.8 ft^). The

following sections include the rationale for each fire size, computer modeling of the facility based on
42 3 Warm Climate -15 m Facility

486-dx2 66 MHz Computer

w/ HPIB Interface Card

z

jrik

Uninterruptable Power

Supply

(UPS)

HP 1301A Data Acq. Unit

w/ HP E1326 Multimeter

TT ITT

II II II I TCI TC16 TC17 TC32 TC33 TC48 TC49 TC64 VI V16

16 CH. Thermocouple Input Module (x4)

Dl

D32

D33

D64

16 CH.Voltage Input Module

32-bit Digital Input Module (x2)

Figure 21 . Diagram of data acquisition system components.
3 Warm Climate- 15 m Facility 43

anticipated heat sources, test procedures, summary of all experiments, and fuel specifications.

Two wood crib fire tests, 0.6 m x 0.6 m x 0.6 m and 0.6 m x 0.6 m x 1,2 m, were also conducted.

These were to simulate an ordinary combustibles fire in a high bay space. The wood crib fires are discussed in the Appendix.

3.2.1 Logic Used to Determine Experimental Fire Sizes

A combination of plume theory, three-dimensional computational fluid dynamic modeling, and

engineering judgement were used to determine the heat release rates and associated pan sizes to meet

the experimental objectives. Each of the experiments can be grouped into one of two categories,

referred to as "detector fires" and "sprinkler fires." Detector fires were designed to determine an

approximate minimum fire size for detection ability for the various types of heat, smoke, and flame

detectors. Detector fires were small square pan fires of three different sizes; 0.3 m x 0.3 m (1 ft x 1

ft), 0.6 m X 0.6 m (2 ft X 2 ft), and 0.9 m x 0.9 m (3 ft x 3 ft). Square pan fires were chosen since the

0.3 m X 0.3 m and the 0.6 m x 0.6 m fires are industry standards for testing of the UV/IR detectors.

The sprinkler fires were larger round pan fires designed to determine the approximate fire size for

activation of the various types of automatic sprinklers. Sprinkler fires were designed to meet three

objectives:

• To demonstrate a large fire that would come close to but not activate any of the installed test sprinklers. The first sprinkler fire was a 1.5 m diameter circular pan fire with an estimated

heat release rate of 4.5 MW

• To demonstrate a fire large enough to activate the 79 °C (175 °F) sprinklers within the fire plume) The second sprinkler fire was a 2.0 m diameter pan fire with an estimated heat release

rate of 8.6 MW.

• To demonstrate a fire that would activate the 79 °C (175 °F) sprinklers inside and outside the

fire plume and possibly the 141 °C (286 °F) within the fire plume. The third sprinkler test was

a 2.5 m diameter pan fire with an estimated heat release rate of 12.6 MW.

Draft curtains were fabricated and installed in the 15 m facility to enclose an area 24.4 m x 18.3 m (80

ft X 60 ft). The draft curtain was 3.7 m (12 ft) deep. Most of the experiments were repeated without

the draft curtain to determine the effects of the draft curtain.

3.2.2 Computer Modeling of 15 m Facility

Computer modeling was used extensively as a design tool to predict the effects of fire size on ceiling

temperature, smoke movement, and sprinkler activation. Use of computer models to aid in the design

of the hangar experiments was based on some successful results obtained modeling test fires in a 30 m

(100 ft) hangar. [3] The initial modeling effort was directed toward the establishment of fire sizes that would just activate the 79 °C and 141 °C sprinklers based on the expected ambient temperatures at the

hangar site. Draft curtains were assumed to be absent for this analysis.

Initially, the zone fire models LAVENT [27] and DETACT-QS [28] were used to establish target fire
44 3 Warm Climate -15 m Facility

sizes. The computational fluid dynamics model, HARWELL-FLOWSD [29], was then used to refme

the target fire sizes and investigate the impact of the ceiling geometry on sprinkler activation. The

CFD model allowed for the calculation of temperatures and sprinkler activation times within the plume

region. Neither zone model contained physical models which are valid for sprinkler activation inside

the plume.

Modeling parameters for the CFD model used here are reported in reference [3]. Three target fire sizes were selected to test sprinkler activation. The first fire size was 4.5 MW which was not expected

to activate any sprinklers. The second fire size of 8.1 MW was expected to produce ceiling

temperatures sufficient to activate the 79 °C heads within 2.5 m of plume center but none of the

120 °C heads. The final fire size of 12.6 MW was expected to activate a 141 °C head at plume center but none of the other 141 °C heads. The 79 °C heads were predicted to activate out to about 5.5 m

from plume center for this fire.

The impact of the 5 degree ceiling slope on smoke movement (assumed to travel with the heat) was

investigated using the CFD model. The effect of the 5 degree slope was found to exhibit only a small

enhancement of smoke flow down slope. Figure 22 shows the predicted temperature distribution at 30 s after ignition. The long rectangular slice extending out to the left in the figure represents a

horizontal plane at the bottom of the monitor window. Since the ceiling slopes five degrees down

toward the left of the figure, the plane showing the location of the hot gas stops when the ceiling slope

intersects the height of the plane. The ceiling is flat in the up-down direction in the figure. The fire is located at the upper left hand corner of the figure with the contours representing different temperatures.

As can be seen from the figure, there is substantially more flow of heat in the flat direction then in the

sloped direction.

Simulations using the 8.6 MW fire size and draft curtains for a 18 m x 24 m area were done using

LAVENT and the CFD model in order to predict the temperature structure of the ceiling jet. The fire was assumed to grow quadratically in time and to reach full involvement in 10 s. The two model

calculations were compared 90 s after the start of the fire. The calculated ceiling jet temperature

profile, using the CFD model, predicted a nearly flat temperature profile 6 m from plume center while

the temperature profile derived from LAVENT predicted a substantial fall-off in temperature with

distance beneath the ceiling. Based on the calculations, thermocouple trees were designed to monitor

temperatures with a 0. 15 m resolution covering a distance of 0.76 m beneath the roof in order to measure the temperature profile of the ceiling jet.

Modeling the impact of draft curtains versus no draft curtains was also done using the CFD model.

Initially draft curtains 5.5 m deep were investigated for spaces with areas of 18 m x 24 m and 24 m x 24 m. Only small differences in ceiling temperatures were obtained with the different draft curtain

configurations. It was found that the presence of draft curtains slightly increased the temperature within

the curtained region and produced a more uniform temperature distribution within the curtained region.

Based on the modeling results, it was decided to use the 18 m x 24 m draft curtain configuration. The

curtain depth used for the experiment was decreased to 3.6 m based on present fire code regulations.

3.2.3 Experimental Procedures and Test Information

A test procedure was developed to coordinate the many tasks required to conduct each full scale

experiment. These tasks were supervised by the project leader according to the following procedures.
3 Warm Climate -15 m Facility 45

Hawaii Hangar

Temperature 30s

8.1 MW Fire

•

M> 1 27

^ 56.5

33

< 33

Figure 22. Top view of 15 m high facihty as viewed in horizontal plane near ceiling. The fire is located in upper right corner. Temperature representation stops when horizontal plane

intersects ceiling. The monitor window located on roof is represented by rectangle

which extends beyond the intersection of plane and roof.
46 3 Warm Climate- 15 m Facility

Equipment Check

Instrumentation and fire protection devices were inspected before each experiment. Thermocouple and

sprinkler connections were electronically checked to ensure no open circuits. Initially, thermocouples were tested with a small heat source to ensure temperature response and switch-like sprinkler

connections were inspected to verify operation. Each data channel was checked for proper

measurement and response. Channels or measurement points with incorrect or intermittent operations were repaired. The data system was readied for the upcoming experiment. Power supplies and

controllers for wind speed transducers, the linear heat sensor, the load platform, and mass flow

transducers were examined for proper operation. Water supplies for the three water-cooled

radiometers were inspected for proper flow. Video cameras used to record the test were positioned.

The camera designed to aid in flame height measurements was placed at a known distance from the fuel

pan with a backdrop of elevation markings at 0.6 m intervals from the floor.

Projected beam detectors were inspected for proper ahgnment and operation. A nominal output voltage

of four volts from each detector confirmed operation. A lower output meant the detector's lens was

dirty or the unit was defective. Lenses were manually cleaned after nearly all experiments. Smoke and

heat detectt)rs were inspected to confirm acceptable operation and the central fire alarm panel provided

a measure of percent-of-alarm for each detector. Generally, a value greater than 1 % to 2 % suggested

that the detector needed to be cleaned or replaced. To speed these changes, detectors were installed

onto mounting plates so they could be easily removed. Upon completion of the larger fire tests, most

detectors were replaced. UV/IR detectors were located at pre-determined distances from the fire pan.

A small hand held source, used as a calibration, was directed at each detector and necessary

adjustments were made. The temperature of the water contained in the sprinkler piping was measured.

If the temperature of the water was higher than ambient, the water was drained and the piping refilled. At this point a portable motor generator system was started to provide backup power for all data

systems, power supplies and controllers.

Set Fuel Pan

The next major step in the procedure was to position the load platform and appropriate fuel pan. It was

critical that these elements were centered so that measurements concerning plume symmetry,

temperature and smoke movement could be referenced to a consistent central location. The pan was

then leveled on the load platform and the weight of the empty pan was measured using the load cell controller. An LED indicator on the controller provided a continuous display of the weight in appropriate engineering units. Depending on the pan size (i.e., 1.5 m, 2.0m, and 2.5 m round pans),

a larger load platform was used. For the later experiments conducted without the load platform which was destroyed during test 6, fuel pans were placed on a circular arrangement of concrete blocks 0.3 m

(1 ft) high. For the wood crib experiments a separate platform configuration and ignition sequence was

used. All information on wood crib fires is documented in the Appendix.

The fuel (JP-5) was transported into the hangar via a small fuel truck. All activities concerning fuel transport were supervised by fire fighting personnel to safeguard the operation. Fuel was pumped from

the fuel truck into calibrated buckets to measure the volume. Once measured, the fuel was carefully

poured from the buckets into the pan. This method of volume measurement has an estimated

uncertainty of +0.47 f (0.5 quarts), based on the error in reading the fuel volume from the buckets,

and any spillage occurring during fuel transfer. Another weight measurement was recorded for initial
3 Warm Climate -15 m Facility 47

weight of fuel in the pan. Once again, a check on the stabiUty and center position of the pan was made.

At this point a final check of all instrumentation was made. The floor based radiometer was positioned

at a predetermined distance from the pan. Each UV/IR detector was positioned and aimed at the fire pan using a small visible laser mounted on the side of the detector.

Building Check

The positions of main hangar and side maintenance doors throughout the hangar were confirmed. One

experiment conducted required hangar doors to be partially open. However, for the other tests all doors were closed. Other openings such as skylights and ventilation fan louvers were closed and

secured. The base fire personnel were notified to stand ready. For the larger fire tests, a charged hose

line containing AFFF was brought into the hangar in case an emergency shutdown was necessary. Fire

fighting personnel were provided protective suits and breathing gear.

Countdown Sequence

Once all instrumentation, fuel pan, and building checks were completed a countdown sequence was

initiated. The project leader notified all participants to enable their data systems and record necessary

ambient conditions. Personnel who operated hangar doors for post-test smoke evacuation were told to stand ready. Video cameras began recording. The data system used to measure temperatures,

sprinkler activation, and other fire parameters began recording background information.

The fuel in the pan was ignited using either a propane or acetylene torch. Ignition time was defined by

sustained burning of the fuel when the torch flame was removed. A member of the test crew signaled

ignition. At this point, the ignition time was noted and the remaining data recording systems were

begun. A stopwatch was started at the time of ignition.

During Tests

Visual observations of plume symmetry, smoke filling, smoke movement throughout hangar, and

burning characteristics, including flame spread rate across the pan, were noted along with the elapsed

time. Photographs of important events which occurred during the experiment were taken. Throughout

the experiment, safety temperatures (i.e., steel beam and fuel pan) were monitored to ensure that structural integrity of the hangar was not at risk. Also, smoke depth above the floor was monitored. If any of these conditions surpassed established risk protocol or other serious conditions arose, the project

leader would terminate the experiment and take appropriate action to evacuate the building and begin

suppression procedures. The tests continued for nominally ten minutes or until temperamres near the

ceiling reached equilibrium.

Suppression and Smoke Evacuation

Upon completion of the experiment, the project leader signaled the suppression crew to begin the

extinguishment process. The suppression crew consisted of base fire personnel and team members with

fire fighting experience all equipped with required safety gear. COjtype extinguishers were used to suppress the smaller fires. For the larger fires, a combination of COj extinguishers and a suppression

lid mounted on long handles was used. As the lid was lowered over the pan, COj was applied to the
48 3 Warm Climate -15 m Facility

flame, thus inerting the space underneath the Hd. This method proved very efficient in not only

suppressing the fire but protecting the load platform electronics and without spilling large amounts of

fuel. One emergency shutdown was performed because the burning pan tihed and spilled fuel on the

floor creating a potential hazard. In this case, the hose line filled with foam was employed and as a

result the load platform was destroyed and an extensive clean-up of the area was necessary.

In all cases, once the fire was suppressed, hangar doors and skylights were opened to evacuate the

smoke. During this time, all nonessential personnel were evacuated from the building. Members of

the fire fighting crew remained near the extinguished pan to ensure complete suppression and prevent

potential re-ignition of the fuel.

Data Reduction and Fuel Removal

Once the smoke had been evacuated, participants reentered the building and returned to their stations. Data systems were reset and files were transferred to backup media. Results were printed and graphed

for analysis. The residual fuel in the pan was removed once the temperature of the fuel decreased well

below its flash point. Small hand pumps were used to transfer the residual fuel into the calibrated

containers for material volume measurement. The fuel was then discarded into scalable steel drums

and removed from the building. The base hazard materials team performed all fuel transfers and clean- up.

Discuss Results with Participants

The final process was to discuss the results from the previous experiment. Interesting events and

unusual behavior of instrumentation were also discussed. Participants evaluated instrumentation

damage and/or changes required for the next experiment. The project leader was responsible for

evaluating all results and planning the next experiment accordingly.

Test Information

Thirteen experiments were conducted in the 15 m high facility. Using the above procedures for each

experiment. Table 9 contains a summary of important information relevant to each experiment,

including the date and time the experiment was conducted, pan size, fuel type, ignition tune, and test duration.

3.2.4 Fuel SpeciHcations

All experiments conducted in the 15 m facility utilized JP-5 jet fuel. The base fuels department

conducts certain standard tests on each batch of fuel delivered to the base. The fuel properties for the

JP-5 utilized in these experiments as reported by the fuels department laboratory at Barbers Point Naval

Air Station are listed in Table 10. These values were in the acceptable range as required by the

military specification for JP-5 [5]
3 Warm Climate -15 m Facility 49

Table 9. Test information for each experiment conducted in 15 m high facility

Test

Number

Date Time Pan Size Fuel Type Ign.

Time

(s)

Test

Duration

(s)

1

2

3

4

5

6b^

2/17/95

2/17/95

2/17/95

2/18/95

2/18/95

2/18/95

14:13

17:10

19:30

10:59

15:04

22:05

0.3 m X 0.3 m

0.6 m X 0.6 m

0.9 mx 0.9 m

1.5 m Diameter

2.0 m Diameter

2.5 m Diameter

JP-5

JP-5

JP-5

JP-5

JP-5

JP-5

370

256

144

209

291

90

977

727

673

578

537

563

7"

8

11

12

13"

2/19/95

2/19/95

2/20/95

2/20/95

2/20/95

2/20/95

2/20/95

15:03

18:48

11:28

11:58

12:53

13:40

16:30

2.0 m Diameter

2.5 m Diameter

0.6 m (cube)

0.6 mxO.6 mx 1.2m

0.3 m X 0.3 m

0.6 m X 0.6 m

2.0 m Diameter''

JP-5

JP-5

Wood Crib

Wood Crib

JP-5

JP-5

JP-5

93

617

40

226

161

37

150

744

517

275

615

681

735

155

^ Test 6a was aborted.

'' The draft curtain was removed for tests 7-13.

" All data for wood crib fires (tests 9 and 10) is available in Appendix [ ].

'' Test conducted with both hangar doors partially open as described in section 6.3.1,
50 3 Warm Climate -15 m Facility

Table 10. Fuel specifications for 15 m high facility experimental fires

Parameter Specification

Fuel Sample JP-5

Date Taken

API Gravity @ 15 *»€

2/17/95

40.9

Specific Gravity 0.8074

Density (kg/m^) 807.1

Flash Point {°C) 60.0
3 Warm Climate -15 m Facility 51

3.3 Fire Behavior in 15 m Hangar

Table 9 is a list of all the fires set in the 15 m hangar at Barbers Point. The JP-5 pools smaller than 1 .0 m are classified "detector fires" because they were designed to check the response characteristics of

various fire detection schemes. The behavior of these fires is described in the following section. Fires

larger than 1.0 m are classified as "sprinkler fires." These were chosen to challenge different sprinkler

activation designs, and are discussed in section 3.3.2. The two wood crib fires were used to investigate

the response of the detection systems to a Class A fire; these are outside the focus of this report but are included in the Appendix for completeness.

3.3.1 Behavior of Detector Fires

There were five detector fires conducted in the 15 m high facility, three with the draft curtain in place

and two without the draft curtain. All the detector fires were conducted on the single point load

platform and used JP-5 aviation fuel. Fires were all positioned at the test center point as described in Figure 4. Detector fires were ignited at one corner of the fire test pan. The 0.3 m x 0.3 m fires were

ignited with a propane torch and the 0.6 m x 0.6 m and the 0.9 m x 0.9 m fires were ignited with an

acetylene torch. The ambient fuel temperatures ranged from 27 °C to 31 °C. It took over 60 s to achieve sustained combustion with the propane torch and between 5 and 10 seconds to achieve

sustained combustion with the acetylene torch. Table 1 1 provides the test information for each detector

fire conducted. Information in the table includes pan size, ambient temperatures, time for the fire to spread across and fully involve the fire pan, and steady state flame heights as measured from the video.

All detector fires were allowed to burn at least ten minutes.

Table 1 1 . Information on detector fires conducted in 15 m high facility

A Tn r\1 f^T^t Full Pan

Involvement

Steady State

Test Number Pan Size Flame Height

rVniUlCllL

Temperature

m °C s m

1 0.3x0.3 27 < 5 0.9

^,^,.,..^.„.„^.,^..„2.,^ 0.6x0.6 28 10 23

3 0.9x0.9 27 20 3.7

11 0.3x0.3

^..:.:.:,-. -.:.:...... .:........-:.. .,,,,.,,,,,,,^ 5 ''''"'^""oT'''^''''"""

12 0.6x0.6 31 10 2.3

Plume Symmetry

The spatial location of the plume near the ceiling was determined using both the regular array of

thermocouples located 0.15 m beneath the ceiling at radial positions of 1.5 m and 3.0 m in the

experimental N, S, E, and W directions from the geometric center of the fire and the array of

thermocouples located 3.0 m beneath the ceiling at radial positions of 0.0 m, 0.9 m and 2.1 m in the N,

S, E, and W directions from the geometric center as previously described. The initial position of the
52 3 Warm Climate -15 m Facility

plume near the ceiling was determined using the arrival time of the hot gas at each thermocouple, while

later plume positions were deduced from comparing the relative temperature of symmetric pairs of

thermocouples for the thermocouple array at the ceiling and 3.0 m beneath the ceiling. An idealized

plume has its highest temperature on its center line with mixing of the entrained ambient air causing the

temperamre distribution to decrease radially outward. The largest uncertainties in the determination of

plume center occur due to thermal irregularities in the plume and to the fact that thermocouples were

measured sequentially. The time between adjacent thermocouple readings was normally less than

1.5 s.

Videos of the fire taken using cameras looking north and east were also used to determine the lean of

the flame and lower plume. While the location of the smoke plume at the ceiling was either not

available or difficult to determine owing to poor visibility at the ceiling, the lean of the flame and lower

plume provide some confirmation of plume lean as determined by the thermocouples at or near the

ceiling. The flame leans are determined based on the position of the tip of the continuous part of the

flame compared to the location of the edge of the pan. This measurement should be regarded as an

estimate with an accuracy equal to about 25 % of the pan edge or diameter.

Two 0.3 m X 0.3 m tests were conducted, one with and one without draft curtains. These tests produced temperature increases at the ceiling of only 0.5 °C and 3 °C respectively. For the curtained

test, comparison of the thermocouples C5, C7, C9, and Cll reveal that the plume leaned toward the

north for the first 280 s of the test, then leaned south for the next 250 s and then was centered for the

rest of the test. In the E-W plane, the plume initially had a slight east lean for the first 150 s, was

centered for the next 150 s, and then leaned west for the remainder of the test. The video observations

indicated an early SE lean for the flame which was estimated to be about 0.2 m to both the east and

south directions. The lean to the east persisted till at least 210's into the test but the lean to the south

disappeared about 150 s into the test. For the uncurtained test, thermocouple S7 consistently yielded

temperatures higher than any of the other thermocouples in the array located 3.0 m below the ceiling,

implying that the plume was centered about 2.0 m south of geometric center. Video observations

suggest the fire was fairly well centered in the N-S direction till after the first beam detector activated,

at which time the fire exhibited a slight lean to the north. In the E-W direction, the fire exhibited a

fairly consistent lean of about 0.3 m towards the east throughout the test.

Two 0.6 m X 0.6 m tests were conducted, one with and one without draft curtains. For the test with

the draft curtains, a significant shift of the plume center to experimental east was observed early in the

fire as thermocouples E15 and E16 produced higher readings than thermocouples WIO and Wll, with

thermocouple E15 reading higher than thermocouple CI which was located at the geometrical center of

the fire. This suggested that the plume center was located at least 1.5 m south of fire center. There was an early indication of a shift in plume center to experimental south but this shift was much smaller

than the shift to the east. Video observations showed that the flame was centered at the beginning of

the test but by 70 s had begun to lean to the west by 0.2 m. At 120 s, the flame again became centered

and remained that way until about 240 s into the test when it began to lean to the N-W. At about 300 s into the test, the N-W lean reached a maximum of about 0.3 m in both the north and west directions

and then moved to the west at 360 s and then to the north at 420 s. The north lean maximized at 0.4 m

at 450 s with an additional 0.2 m lean to the west. The plume center for the test conducted without a

draft curtain shows a substantial shift to the south-west with both thermocouples C6 and C8 recording

temperatures higher than thermocouple C3 located at the geometric center of the fire. Estimated plume

center location was about 1 .0 m to the south and almost the same distance to the west. Video
3 Warm Climate -15 m Facility 53

observations of the flame displayed an initial lean of 0.2 m to the west at the beginning of the test. At

about 25 seconds into the test, the flame became centered and then at 120 s, returned to the 0.2 m S-E

lean. At about 180 s the flame centered in both the E-W and N-S directions and then at 210 s it returned to a lean of 0.2 m to the south.

The plume for the 0.9 m x 0.9 m test indicated a plume center that was located about 0.5 m to the

north and just slightly off center to the west. The displacement to the north was estimated by comparing

thermocouples C3 and C4 located at the center and 1.0 m to the north respectively. These

thermocouples recorded almost identical temperatures indicating that the plume center was located

about midway between the two thermocouples. The video records for this test indicated that in the N-S

direction the flame started out centered but was leaning 0.2 m north by 90 s into the test. The flame

remained in a northward orientation but swayed from being almost centered to leaning as much as 0.4

m to the north. In the E-W direction, the flame started out leaning 0.2 m to the west, centered at 25 s, and then by 120 s was leaning 0.1 m to the west. This westward lean reached 0.2 m by 150 s when the

flame began moving back toward the center. For flame remained centered till about 360 s when it again moved to about 0.1 m to the west.

Temperature

Thermocouples at the ceiling of the 15 m high facility were evaluated to determine the temperature rise above ambient temperature for all detector fires. This information can be used to compare how

temperature varies with fire sizes and to validate temperature predictions of various models.

Table 12 shows the maximum temperature in the center region of the test area and the corresponding

rise above ambient temperature. The maximum temperature rise was determined by evaluating

thermocouples located 0. 15 m below the ceiling deck and within a 3.0 m radius of the fire centerline.

Thermocouples used were the following: center (CI), 1.5 m north/south/east/west (Nil, SIO, E16,

WU), and 3.0 m north/south/east/west (NIO, S9, E15, WIO). The temperatures reported are based on

analyzing the temperature range over the time interval where the fire's mass loss rate appeared steady

and choosing a value equal to ninety percent of the range. Since the temperatures throughout this range were increasing, the maximum value generally occurred late in the test. By evaluating the

central region of temperatures for each test, the effect of plume lean on center temperature is somewhat

minimized.

Maximum temperature with respect to time for the thermocouples within a 3.0 m radius from center at 0.15 m below the ceiling are presented in Figures 23 and 24. Figure 23 shows the detector fires conducted with the draft curtain (tests 1, 2, 3) and the Figure 24 shows the detector fires conducted

without the draft curtains (tests 11, 12). In this central region temperatures are similar in magnitude for

both the draft curtained and non-curtained cases.

Table 13 indicates maximum temperatures at specific locations with respect to the draft curtain. All

entries are for thermocouples located 0.3 m below ceiling deck. For example, temperatures at 8.5 m

north and south are located just inside the draft curtain as is the temperatures at 11.6 m east and west. This position in the north and south direction is located outside the draft curtain. Thermocouples at 14.6 m east and west are located outside the draft curtain. Omitted entries in the table are locations

where temperature measurements were not made or are duplicates of other measurements.
54 3 Warm Climate -15 m Facility

Table 12. Temperature rise above ambient for detector fires

Test Information Temperature Parameters

Test NumberPan Size

m

HRR

MW

Maximum

Temperature^

°C

Ambient

Temperamre, T^b

°C

Rise Above Tamb

1 0.3x0.3 0.1 31 27

0.6x0.6 0.5 44 28 16

0.9 X 0.9 1.9 56 27 29

11' 0.3x0.3 0.1 34 31

12^ 0.6x0.6 n/a 44 31 13

^ Maximum temperature found by evaluating thermocouples at center, 1.5 m, 3.0 m (NSEW), 0.15 m below deck

^ Tests conducted without draft curtains

Hot Gas Flow

The impact of the draft curtain on hot gas flow can be seen from the data presented in Table 14. The

filling time for the draft curtain was determined by comparing temperatures measured with the

thermocouple tree located at 9. 1 m east of fire center to the tree 3.0 m inside the edge of the draft

curtain. Based on the times required for the thermocouple located 3.0 m below the ceiling to record a temperature rise, the draft curtain filled in 100 s and 67 s for 0.6 m x 0.6 m pan and the 0.9 m x 0.9 m

pan, respectively.

The times for the hot gas to reach the 6. 1 m position and the edge of the draft curtain are essentially the same for all fire tests. The reason for this is that each fire pan was only ignited at one corner. For the

early timing measurements, the fire size depends on how much of each pan has become fully involved

and not on pan size. Since the ignition method was approximately the same for each pan size, the

flame spread and hence the fire size will be the same for each pan size early in the test. Variations in

the timing will occur due to uncertainties in the fire start time, the initial fuel temperature, and in the

initial amount of area ignited by the torch.

With the draft curtain in place, the transport time of the hot gas to the ceiling was approximately 18 s for the 0.3 m x 0.3 m pan fire, 8 s for the 0.6 m x 0.6 m pan, and 13 s for the 0.9 m x 0.9 m pan.

Arrival of heat at the ceiling was indicated by a temperature rise on one of the thermocouples 0.3 m

below the ceiling over the test center point or at 1.5 m radially out from test center. Without the draft

curtain in place, transport time to the ceiling was 24 s for the 0.6 m x 0.6 m fire. Transport time was

not measurable for the 0.3 m x 0.3 m fire without the draft curtain due to the very slight temperature

rise at the ceiling. Major uncertainties in determining the transport time of hot gas to the ceiling

include; accurate determination of the starting time for the fire, initial plume lean, and the coarseness

of the measurement interval which varied between 3 s to 4 s. A comparison of the time for the draft curtain to fill with the time for the hot gas to reach a thermocouple outside the draft curtain can be used to determine if the draft curtain fills before spilling

into the adjacent area. For these comparisons, the ceiling thermocouple at 14.6 m east is used to determine spillage time outside the draft curtain while the thermocouple at 9.1 m east, 3.0 m below the

ceiling, is used for draft curtain filling. The reason for using only the east thermocouples is to attempt
3 Warm Climate -15 m Facility 55

60

50

o

(D

i- I 40

Q.E

0)

30 -

20

-e— Test 1 Maximum Temperature

-• - Test 2 Maximum Temperature -^— Test 3 Maximum Temperature

^1 P\h \i

SJ"^^ K

Av4a/w^-/^""V

n I 1 r

1—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I

\—I—I—I—I—I—1—I—I—I—I—I—I—

r

I ' ' '

I I

' ' ' I 60 120 180 240 300 360 420 480 540 600

Time (s)

Figure 23. Maximum temperatures for detector fires conducted with draft curtains.
56 3 Warm Climate -15 m Facility

45

40

35

oo?3

2

0)Q.

E

30

25

20

-e— Test 1 1 Maximum Temperature

-• - Test 12 Maximum Temperature

/w'V^

60

1—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—I—

T T I

' ' '

I T

120 180 240 300 360 420 480

Time (s)

T

540 600

Figure 24. Maximum temperatures for detector fires conducted without draft curtains.
3 Warm Climate -15 m Facility 57

Table 13. Maximum temperature rise at various locations

Test Inft)nnation Maximum Temperature Rise Above T^^ (°C)

Test

Number

Pan Size

m

T* amb °c

Location 6.1m 8.5 m^ 11.6 m'' 14.6 m^

1w/

Draft

Curtain

0.3x0.3 27 north

' ''f"''"'' 1

::x:K:::;:::;:-:(J«

:::;::::;:::-::;:: :x:x:::x:;:x::::W^::>::: :-:>: ::::•:

south 4 3 1 -

east 2 ~ 2 1 west 3 - 2 1

11 0.3x0.3 31 north 1 2 2 —

ti///^ w/o south 2 1 1 ~

Ulall Curtain

east 1 — 1 1

2 0.6x0.6 28

west

north 13 10

141

w/

Draft

Curtain

south 14 10 3 ~

east 9

-- 9 5

west 9 - 9 4

12

w/o

Draft

Curtain

0.6x0.6 31 north 8 6 5 —

south 9 6 6 -

east 8 ._ 4 4

west 5 ~ 4 3

3

w/

Draft

Curtain

0.9x0.9 27 north 24 20 9 ~

south 21 18 7 ~

1 o east 21 11 _- lo

west 16 ~ 17 8

* Located near inside edge of north and south draft curtains

^ Located near inside edge of east and west draft curtains, outside DC in north and south direction

•^ Located outside draft curtain in east/west direction ~ Temperature not measured at this location

to minimize the impact of plume lean on the comparisons. The difference in time between the hot gas

flow registering a temperature rise outside the draft curtain and the time to fill the draft curtain are 1 1 s and 6 s respectively for the 0.6 m x 0.6 m and 0.9 m x 0.9 m pans. Since the hot gas flowing over the

bottom of the draft curtain must rise to the ceiling and flow radially outward an additional 2.4 m, the

data suggests that the hot gas flows under the draft curtain prior to filling the draft curtain.

Ceiling Jet Velocities

Ceiling jet velocities were determined using two hot wire anemometers as described earlier. The

anemometers were located 6.1 m to the east and north of fire center and 0.15 m below the ceiling.
58 3 Warm Climate -15 m Facility

Table 14. Hot gas flow results (s) for experiments conducted with draft curtain

Draft Curtain

Test Pan Size, m

Curtain Filling

Time

Time to 11.6m

East Time to 14.6 m

East Time from

6.1 m to 11.6 m

East 0.6x0.6 100 43 89 13

0.9x0.9 67 38 61 12

1.5 diameter 50 38 57 14

2.0 diameter 38 42 48 17

2.5 diameter 32 29 39

Table 15. Maximum ceiling jet velocity and radiation measurements

Test

Pan Size, m

CJ east m/s +0.1CJ north

m/s +0.1

Rad. 1 kW/m^ +0.25

Rad. 2

kW/m' +0.25

Rad. 3

kW/m^ +0.25

0.3x0.3'' n/a n/a n/a n/a n/a

03x0.3 0.1 0.2

0.6x0.6^ 0.7 0.4

0.6x0.6 0.4 0.2

0.9x0.9^ 0.9 0.7

1.5 dia.^

2.0 dia.^

0.4

0.5

1.3

1.0

2.6

5.4

0.89

0.59

0.91

1.5

2.0 dia. 0.7 L6 4.7 0.67 1.2

2.5 dia." n/a n/a 6.8 1.19 2.4

2.5 dia. n/a n/a n/a n/a n/a

Draft curtain experiment

Measurement of maximum ceiling jet velocities in all experiments are presented in Table 15. The

anemometers were oriented such that only the component of the velocity parallel to the ceiling would

be measured. The anemometers were limited to a maximum temperature of 120 °C. Temperatures in excess of this amount would cause a low or zero velocity reading.

Maximum velocity readings for the 0.3 m x 0.3 m test without a draft curtain were 0. 1 m/s east and

0.2 m/s north. The 0.3 m x 0.3 m test with a draft curtain did not have velocity measurements due to an instrument failure. Maximum velocity readings for the 0.6 m x 0.6 m tests were 0.7 m/s to the east
3 Warm Climate -15 m Facility 59

and 0.4 m/s to the north for the draft curtain test and 0.4 m/s to the east and 0.2 m/s to the north for

the test without the draft curtain. Based on the plume symmetry observations, both measurements were made outside the plume region. The 0.9 m x 0.9 m test gave velocity readings of 0.9 m/s east and 0.7

m/s north. The plume leaned to the north and west for this test but the north readings did not indicate

the anemometer was in the plume.

Heat Flux Measurements

Total heat flux (primarily radiation) was measured at three positions using water-cooled Gardon type

heat flux transducers. Each transducer was aimed directly at the fire center. The first transducer was

placed approximately 5 m east of fire center and was located 1.22 m above the floor. The second

transducer was located 9.8 m above the floor and 6.1 m east of fire center while the third was located

0. 15 m below the ceiling and 6.1m east of fire center. Heat flux results are shown in Table 15. None

of the flux meters recorded measurable signals from the detector fires.

Heat Release Rate

Two methods were used to determine the heat release rate for the detector fires. The first method

employed direct measurement of the mass loss rate of the fuel. The heat release rate was then

determined by multiplying the measured mass loss rate by the heat of combustion of the fuel. For those

tests where the mass loss rate was not measured due to instrumentation failures, an approximate measure of the mass loss rate was made by determining the volume of fuel burned during the test and

using the density of the fuel to calculate the average mass loss over the duration of the test. Since the

final volume measurement for the fuel was not made until the fuel had cooled down below the flash

point, the final volume measurement would include any losses due to fuel vaporization and

extinguishment losses during fire suppression. In all cases, suppression was performed with a lid supplemented by CO2 fire extinguishers at the pan edges. This technique was used to minimize residual

fuel losses and protect the load platform electronics. Direct measurement of the mass loss rate using a load cell was performed for the 0.6 m x 0.6 m, 0.9 m x 0.9 m, 1.5 m diameter, and 2.0 m diameter

pans for the fire tests conducted with draft curtains. The mass loss rate for all the other tests were

calculated from the fuel volume consumed by the fire.

Where load cell data were available, a linear curve fit was used to determine burning rate after an

approximate steady state condition was reached. Figure 25 shows an example of the steady state analysis of the mass loss data. For the fire tests where the consumed volume method was used, the

volume of fuel consumed was divided by the total test time in order to obtain an average mass loss rate. The estimated steady state heat release rates for the draft curtained fires are 0.1 MW for the 0.3 m x

0.3 m pan, 0.5 MW for the 0.6 m x 0.6 m pan, and 1.9 MW for the 0.9 m x 0.9 m pan. Additional

data including the mass loss rate for all tests are shown in Table 16. Omitted entries in the table indicate load platform malfunction and incomplete volume measurements of residual fuel. Each

experiment was run for a minimum of ten minutes. The burning rate increased during the early part of

the fire until steady state burning was reached. Temperature profiles in the plume, similar to those

shown in the previous figures, were analyzed to determine a consistent time range where the

temperature increases were of a uniform nature. Factors such as plume lean and burning off the side of

the pan were considered. The values for steady state time are show in Table 16. The time required to reach steady state varied with pan size, with the larger pans generally requiring more time to achieve

steady state.
60 3 Warm Climate -15 m Facility

35

o) 30

<u

11.O

w

03 25 -

20

Test 2, 0.6 m X 0.6 m pan, mass loss (kg) Linear fit of steady state conditiion —\—

120 —I

240 360 480 600 720

1 in Time (s)

1 lU

100 -

3)

"O) u.

90 -

o

tow

03 80 - ^\^

70 -

Test 4, 1.5 m diameter pan, mass loss (kg) Linear fit of steady state condition \

^ 60 -

1 ' 1 ' 1

'

1 120 240

Time (s)

360 480

Figure 25. Examples of mass loss curves and linear fit of steady state region.
3 Warm Climate -15 m Facility 61

CO

0)

(U

1-1

'o

<4-l

6

«n

^—

(

a-o

13

o

do

I

1)

l-l I;-i I

(U

«-i (U

13

VO

'' ^ c ^ o

Cfl <-< r^ t^ m 00 r- (^ rt t-- ^H in in

<u re; cfl r~- r^J r- r-~ ro so ^ 00 f<i in H ^

as r~~ so m m >n r- •n so r- D

Steady

State Range s o8 1 -^ o o

1 -^ li

1 ^ o <== o2 ' o O 00

' o O 00 o o o o o o (N ^O in m 00 tT in rf in so in so 00 (^

Full Pan

Involv. s ±

5 m o o o m o in o

m O in V (N m CO ^ (^ '^ V m

. .

Rise

Abov Amb ^ so OS•<* 00

00 c-~ . CO

c<^ m so

•S B . U r- oo r- r~- I^ >n o ON ^ _ 00 H (U o (N r4 cs (N (N (N ro (N m m (N < H

kx

Cente Temp

Max m ^

so

in in O in 5 OS

HRR (load) MW

±0.1 C3 in o\ 00 00 rt <n w c« cfl rt ^ d ^^ (N so "S ^ a ^ C a

HRR (vol.) MW

±0.1 1-H <n T^ r—

(

w r- so a 1-H « rt d d —

'

rn c r-~-' in e d ^ ^

CO .—(

^ J CO ro o

Burn Rate (load kg/m"

±0.0C O o

soO

o

o

C3 «

"^ O o O o

,—V "^ ;z! t-H CN 00 ^ in (^ OS P u '^;^ Q VO On o o so .—1

ci3 'i- But Rat (vol kg/m

±0.C O O o s o o O

O O o o o o O

t3

nj "=^

Fuel

onsum (vol.) ±0.47 oo

04

ID 00d m

as3

so

a^

.—1

OS u

o Tf 00 <N o „ o o o ^ 00 o (T> so O IT) o in o in ro so o

ISQ d O ^^ '"' fN (N <N Csi d O oi

9.§ 6

ft- C/D

X < >< X X m^ ^^ C^^ in 2 P cd in ci 9 c^ in ^ en SO^ '=>. ci d^ d^ d'-^ — TD CM '-3 <--) ^ (N ^ (M "-a d

'-' d "-^ rg --B

C/3 ;i- rj rn ^ «n so

t^ oo ^

(N ro

OX)

'So3

T3C

.a Oi -^ •a

00c

a

Q CO

CuX

(U

k.oo

T3C

<Ua. O
62 3 Warm Climate -15 m Facility

3.3.2 Behavior of Sprinkler Fires

There were six sprinkler fires conducted in the 15 m high faciUty, three with and three without the

draft curtain in place. One experiment with no draft curtain was conducted with the hangar doors

open.

All the sprinkler fires were conducted with the fuel pan on the three point load platform. Fires were all positioned with the pan center over the test center point as shown in Figure 22. Sprinkler fires were

ignited at a single point along the pan edge with an acetylene torch. The ambient fuel temperature was

between 25 °C and 30 °C. It took between 6 s and 10 s to achieve sustained combustion. Table 17

provides the test information for each sprinkler fire conducted. Information in the table includes pan

size, ambient temperatures, time for the fire to spread across and fully involve the fire pan, and steady

state flame heights. Flame height information was obtained through visual accounts and video footage.

Table 17. Information on sprinkler fires

Test Number

Pan Size

Diameter

m

Ambient Full Pan Steady State Temperature

°C

Involvement

s, ± 5

Flame Height

m, ± 0.2

4a 1.5 27 30 7.0

5^ 9 77 35 8 9

6V 2.5 25 40 9.8

7 2.0 30 35 8.2

8 2.5 29 40 9.8

13" 2.0 28 35 c

^ Draft curtained experiment

"^ Open door experiment

" Flame height information not available due to significant flame lean.

Plume Symmetry

The fire plume for the 1.5 m diameter fire with draft curtain exhibited a SE lean early in the test with

the plume center position estimated to be approximately 1 m from geometric center. This estimation is based on the high temperature readings registered by thermocouples C8 and CIO which were located

3.0 m below the ceiling and 0.9 m from center in the south and east direction respectively. The

southward lean seemed to disappear from about 60 s to 210 s and then resumed the southward lean for

the rest of the test. The eastward plume lean continued throughout the test based on the W10 and E15

thermocouples but the lean did begin to disappear starting about 360 s into the test. Video footage

observations of the flame indicate that the flame leaned to the south early in the test in response to asymmetric ignition of the fuel in the pan. The flame centered in the N-S direction in the period

between 60 s and 210 s but did start to lean to the east 90 s into the test with the flame tip reaching

0.75 m by 120 s. This eastward lean persisted for the rest of the test. At about 240 s, the fire started
3 Warm Climate -15 m Facility 63

to spawn small fire whirl structures off the side of the pan.

The fire plume for the 2.0 m diameter fire with draft curtain exhibited a SE lean during the first 6 s of

the test which quickly changed 13 s into the test to a south lean with the plume center located about

1.0 m south of geometric center. At 55 s into the test, the plume changed to an eastward lean moving

as much as 2.0 m from geometric center. It should be noted that this fire plume produced sufficient

rotation to generate a fire whirl which would account for the strong lean and the sharp gradients in plume temperature. About 200 s into the test, the peak temperatures recorded by the thermocouple

array located 3.0 m beneath the ceiling decreased substantially. During the next 100 s period, the

plume tended to lean either about 1.0 m to the south or 1.0 m to the west. At 310 s into the test, the

high peak temperatures reappeared with the plume exhibiting about a 1.0 m lean to the south or west.

Video observations of the flame showed an initial lean to the east which quickly centered by 40 s into

the test. The flame becomes very much eastward oriented by 90 seconds into the test with 0.5 m and

0.75 m leans occurring at about 90 s and 120 s into the test respectively. A slight lean of 0.5 m to the

north developed at 120 s. At 150 s into the test, a large fire whirl was generated which substantially

lowered the flame height over the rest of the pan. By 210 s, the fire whirl disappeared with the flame

leaning strongly to the west maximizing at about 240 s into the test. A fire whirl developed about 290 s into the test which strengthened significantly at 300 s and then subsided 60 s later.

The fire plume for the 2.5 m diameter fire with draft curtain exhibited an initial plume lean in the SW

direction with the plume center estimated to be as much as 2.0 m to the south and about 1.0 m to the west. This lean to the SW became more centered at about 70 s into the test with the plume center

located less than 0.5 m to the SW. For the remainder of the test, the plume tended to lean in the SW

direction, being more south than west for the time periods between 140 s to 160 s and 250 s to 340 s with the plume center being more west of south for the other time periods. Typical flame leans ranged

from 0.5 m to 1.0 m in the above directions.

Video observations of the flame indicated an initial SW lean which disappeared about 60 s into the test. At about 120 s into the test, fuel spilled out of the SW side of the pan, causing additional burning in

this area. The flame leaned to the west in response to the spill, with the flame tip leaning 0.8 m at about 180 s. At about 240 s, a south spill occurred causing the flame to lean south 0.6 m off center for

the next 120 s.

The fire plume for the 2.0 m diameter fire without draft curtain exhibited an initial plume lean to the

SW with the plume center located about 1.0 m to the west and somewhat less than that to the south.

The plume center maintained this position throughout the test with the exception of a westward

migration to about 2.0 m between 500 s and 550 s into the test. The temperature curves for this test indicate three strong temperature pulsations with peaks at about 140 s, 350 s, and 590 s into the test.

Video observations of this test showed the fire plume initially centered in the pan, but at about 60 s the

flame leans to the SW with the tip about 0.5 m off geometric center in both directions. The southern

lean reached 1.2 m at 120 s while the westward lean remained at about 0.5 m. At 170 s, a minor fuel

spill to the west produces a strong westward lean while the flame centers in the N-S plane. At 330 s, small fire whirls are spawned to the west and south with the flame exhibiting a 0.8 m lean to the west

which increases to2.0mat410s.
64 3 Warm Climate- 15 m Facility

The fire plume for the 2.5 m diameter fire without draft curtain was initially centered at the start of the

test but moved to a SE lean at about 30 s into the test. The plume center moved about 0.5 m to the east for the first 100 s and then moved westward to about 0.5 m west of center at about 200 s into the test. The plume centered in the east - west direction about 400 s into the test. The plume leaned initially to the south about 0.5 m off center from about 30 s to about 100 s into the test. The plume then leaned

north for the next 150 s and then centered itself in the north - south direction for the rest of the test.

Video observations of this test showed that the initial pan ignition on the south side of the pan spread

west faster than it spread east. The flame for this test remained fairly well centered with only a slight

lean to the south in the first minute and then a slight lean to the north from 120 s to 240 s into the test. The flame tip leaned only 0.2 m in each case.

With the draft curtain in place, the initial transport time of the hot gas to the ceiling was approximately

11 s for the 1.5 m diameter pan fire, 15 s for the 2.0 m diameter pan, and 7 s for the 2.5 m diameter

pan. Arrival of the hot gas at the ceiling was indicated by a temperature rise on one of the

thermocouples 0.3 m below the ceiling over the test center point or 1.5 m radially out from test center. Without the draft curtain in place, transport time to the ceiling was 11 s for the 2.0 m diameter pan.

Transport time was not measurable for the 2.5 m diameter pan test because of an equipment failure. Uncertainties in determining the transport time of hot gas to the ceiling include determination of the

starting time for the fire, initial plume lean, and the coarseness of the measurement interval which

varied between 3 s and 4 s.

Temperature

Thermocouples at the ceiling of the 15 m high facility were evaluated to determine the temperature rise above ambient for all sprinkler fires. This information can be used to compare how temperature varies

with fire sizes for a fixed ceiling height and to validate temperature modeling. Table 18 shows the

maximum temperature rise in the center region of the test area and the corresponding rise above

ambient temperature. The maximum temperature rise was determined by evaluating thermocouples

located 0. 15 m below the ceiling deck and within a 3.0 m radius of the fire centerline. Thermocouples

used were as follows: center (CI); 1.5 m north/south/east/west (N11,S10, E16, Wll); and 3.0 m

north/south/east/west (NIO, S9, E15, WIO). The temperature values reported are based on analyzing

the temperature range over the time interval where the fire's mass loss rate appeared steady and

choosing a value equal to ninety percent of the range. The temperatures throughout this range were

generally increasing, reaching a maximum value about half way through the test. For those

experiments where mass loss measurement was not available (i.e., tests 6b, 7, 8, 13), the steady state time range was found by evaluating the mid portion of the maximum temperature profile. The steady

state time range in these cases was defined by a steadily increasing temperature without significant high

or low fluctuations. Also, by considering the temperatures within the 3.0 m radius of plume center for

each test, the effect of plume lean on center temperature was somewhat minimized.

To further illustrate, the maximum temperatures as a function of time for the thermocouples within a 3.0 m radius from center and 0.15 m below the ceiling are presented in Figures 26 and 27. Figure 26

shows the sprinkler fires conducted with the draft curtain (tests 4, 5, 6b) and Figure 27 shows the

sprinkler fires conducted without the draft curtains (tests 7, 8). In Figure 26, test 5 shows unusual

burning characteristics. The drop in maximum temperature between 180 s and 300 s was coincident

with observed fire whirls in the plume.
3 Warm Climate -15 m Facility 65

Table 18. Temperature rise above ambient for sprinkler fires

Testlnfc)rmation Tempi^rature Parameters (+ 2 °C)

Test

Number

Pan Size

m

Maximum

Temperamre^

°C

Ambient

Temperature, T.^^ °C

Rise Above T^b

°C

4" 1 5 dia 75 27 47

5" 2.0 dia. 115 27 88

eh'' 2.5 dia. 1 An oc 1 11 14/ Zj 122

7 2.0 dia. 101 30 71

m& - 8 2.5 dia. 152 29 123

13^ 2.0 dia. 60 28 69

^ Maximum temperature found by evaluating thermocouples at center, 1.5 m, 3.0 m (NSEW)

'' Draft curtained experiment

"^ Open door experiment

Table 19 indicates maximum temperatures at specific locations with respect to the draft curtain. For

example, temperatures at 8.5 m north and south are located just inside the draft curtain as is the

temperatures at 11.6m east and west. This position in the north and south direction is located outside

the draft curtain. Thermocouples at 14.6 m east and west are located outside the draft curtain.

Omitted entries in the table are locations where temperature measurements were not made or are

duplicates of other measurements.

Hot gas flow

The impact of the draft curtain on hot gas flow can be seen from the data presented in Table 14. The

filling time for the draft curtain was determined by using the thermocouple tree located at 9. 1 m east of

fire center and 3.0 m inside the edge of the draft curtain. Based on the times required for the

thermocouple located at 3.0 m below the ceiling to record a 3 °C temperature rise, the draft curtain

filled in 50 s, 38 s, and 32 s respectively for fire sizes ranging from the 1.5 m diameter pan to the 2.5

m diameter pan. Figure 28 shows the hot gas flow during the 1.5 m diameter fire experiment. Since the

2.0 m and 2.5 m diameter pans required 35 s and 40 s for the fire to fully involve the pan surface,

respectively, the 2.0 m pan had just reached full involvement and the flames on the surface of the 2.5

m pan were still spreading when the draft curtain filled. The times for the hot gas to reach the 6. 1 m

position and the edge of the draft curtain are essentially the same for all fire tests. The reason for this

is that each fire pan was only ignited at one corner. For the early timing measurements, the fire size

depends on how much of each pan has become fully involved and not on pan size. Since the ignition

method was approximately the same for each pan size, the flame spread and hence the fire size was the same for each pan size early in the test. Variations in the timing occurred due to uncertainties in the

fire start time, the initial fuel temperature, and in the initial amount of surface area ignited by the

acetylene torch.

A comparison of the time for the draft curtain area to fill with the time for the hot gas to reach a thermocouple outside the draft curtain can be used to determine if the draft curtain filled and then

spilled into the adjacent space. Likewise, these comparisons can be used to determine if the hot gas

flows down and around the draft curtain prior to the draft curtain area filling. For these comparisons.
66 3 Warm Climate -15 m Facility

160

140 -

120

o

100

0)Q.E

(D 80 -

60

40

20

Test 4 Maximum Temperature

Test 5 Maximum Temperature

Test 6b Maximum Temperature ^

\

it A

i

f ^^^. ?. nt

Aff

t

i?

^.

/

;

A^ r>

1-1 T ft n f^

-1 I

I T I r I ' ' ' 60 120 180

'

I

' ' '

I

' ' '

I

' 240 300 360

Time (s)

T

1

420 480 540 600

Figure 26. Maximum temperature profiles for sprinkler fires conducted with draft curtains.
3 Warm Climate -15 m Facility 67

160

140 -

120

Oo?3

5

0)Q.E

<u

100 -

80

60

40 -

20

-©— Test 7 Maximum Temperature

-• - Test 8 Maximum Temperature -^— Test 13 Maximum Temperature

Open Door Case

i I ''M T|

60 120 180 240 300

Time (s)

360

'

'

I

' 420

T

480 540 600

Figure 27. Maximum temperature profiles for sprinkler fires conducted without draft

curtains.
68 3 Warm Climate -15 m Facility

Table 19. Maximum temperature rise at various locations

T(jst Inft)rmation Maximum Temperature Rise Above T^n^i, (+ 2.0 °C)

Test NumberPan Size

m

T*amb °c

Location 6.1m 8.5 m^ 11.6 m'' 14.6 m=

4 1.5 27 north 29 31 18 ~

w/

Draft

Diameter south 40 35 15 —

O £L '^C\ -^^ Curtain

east 36 — 29 22

west 26 ~ 29 16

5

w/

Draft

Curtain

2.0

Diameter

27 north 68 60 34 —

south 64 60 34 —

east 68 -- 56 40

west 60 ~ 56 36

7

w/o

Draft

Curtain

2.0

Diameter

30 north 68 60 34 —

south 64 60 34 —

east 43 -- 34 30

west 43 ~ nld.^ 30

6b 2.5 25 north 99 83 14 —

w/

Draft

Curtain

Diameter south 95 83 39 ~

east 85 ~ 73 ST'""""""" west 74 — 69 41

8

w/o

Draft

Curtain

2.5

Diameter

29 north 74 60 46 ~

south 11 62 54 ~

east 64 ~ 48 44

west 56 — 46 40

^ Located near inside edge of north and south draft curtains

'' Located near inside edge of east and west draft curtains, outside DC in north and south direction

^ Located outside draft curtain in east/west direction

^ Faulty reading — Temperature not measured at this location

the ceiling thermocouple at 14.6 m east is used to determine spillage time outside the draft curtain,

while the thermocouple at 9.1 m east, 3.0 m below the ceiling, is used for draft curtain filling. The

reason for using only the east thermocouples is to attempt to niinimize the impact of plume lean on the

comparisons. The difference in time between the hot gas flow registering a temperature rise outside the

draft curtain and the time to fill the draft curtain are -7 s, -10 s, and -7 s respectively for pan sizes

ranging from the 1.5 m diameter pan to the 2.5 m diameter pan. Since the hot gas flowing over the

bottom of the draft curtain must rise to the ceiling and flow radially outward an additional 2.4 m, the

data suggest that the hot gas flows under the draft curtain prior to filling the draft curtain area. Visual

observations of the smoke flowing under the draft curtain confirm this assumption.

Ceiling Jet Velocity

Ceiling jet velocities were determined using two hot wire anemometers located 6. 1 m to the east and
3 Warm Climate- 15 m Facility 69

north of fire center and 0. 15 m below the ceiling. The anemometers were oriented such that only the

component of velocity parallel to the ceiling would be measured. The anemometers were limited to temperatures below 120 °C. Maximum ceiling jet velocities for the 1.5 m diameter test were 0.4 m/s

east (transducer Vj) and 1.3 m/s north (transducer V2). The measurements of ceiling jet velocity for

these larger fires are shown in Table 15. The fire plume in this test exhibited a strong eastward lean

which may account for the low reading by the anemometer in the east. If the anemometer is in the

plume, the strongest velocity component would be perpendicular to the ceiling and would not be

measured by the anemometer. The 2.0 m diameter fire with a draft curtain resulted in velocities of 0.5

m/s and 1.0 m/s to the east and north respectively. This test produced a tornado-type plume. The

north anemometer showed four distinct peaks in velocity during this test which could have been due to movement of the plume. The 2.0 m diameter fire without draft curtain resulted in maximum velocities

of 0.7 m/s east and 1 .6 m/s north. Anemometer measurements for both of the 2.5 m diameter fires were not available due to instrumentation failures. Figure 29 shows sample plots of measured ceiling

jet velocity. The 2.0 m diameter experiments (i.e., test 5) with the draft curtain and the experiment

without the draft curtain (i.e., test 7) are compared. In the upper graph of the figure, ceiling jet

velocities at 6. 1 m east are shown. The lower graph shows the measured velocities at 6. 1 m north.

Heat Flux Measurements

Total heat flux was measured at three positions; the first was 5 m east of fire center and 1 .22 m above

the floor. The second and third transducers were located 6.1 m east and placed 9.8 m above the floor

and 0.15 m below the ceiling. Maximum average fluxes for the 1.5 m, 2.0 m and the two 2.5 m tests are presented in Table 15. Heat fluxes recorded by the third gauge near the ceiling and by the second

gauge located near the beams are higher than would be expected from a simple inverse square law

correlation using a point source near the pan center. Since the sensor near the ceiling is immersed in the hot smoke layer, convective heating of the sensor may produce heat fluxes higher than expected

from radiation alone. (These total heat flux gauges were calibrated with radiative heat flux only.) This

effect is evident when the second radiometer, located at 9.8 m above the floor is compared with the

third radiometer located at the ceiling. In each test, the flux gauge at the ceiling yields a higher reading

indicating that convective heating may have a significant contribution. For these pan fires, the flame

height is substantial. Hence, the heat flux gauges near the ceiling are closer to the flames than the

geometrical distance between the radiometer and the pan center.

Heat Release Rate

The same two methods were used to determine the heat release rate for the sprinkler fires as with the

detector fires. Direct measurement of the mass loss rate using a load cell was performed for the 1.5 m

diameter and 2.0 m diameter pans for the fire tests conducted with draft curtains. The mass loss rate for all the other tests were calculated from the fuel volume consumed by the fire. Where load cell data were available, a linear curve fit was used to determine burning rate after an approximate steady state condition was reached. For the fire tests where the volume method was used, the volume of fuel lost was divide by the total test time in order to obtain an average mass loss rate. The estimated steady

state heat release rates for the draft curtained fires areas follows: 2.8 MW for the 1.5 m diameter pan,

6.8 MW for the 2.0 m diameter pan with draft curtain, 5.6 MW for the 2.0 m diameter pan without

draft curtain, and 7.7 MW for the 2.5 m pan. Two different heat release rates are provided for the 2.0

m diameter pan fires as the fire with the draft curtain produced a tornado-like plume while the pan fire without the draft curtain produced a normal plume. (The 7.7 MW heat release rate for test 8 was
70 3 Warm Climate -15 m Facility

55

50

-o— Thermocouple E9, 9.1 m east, 3.0 m below ceiling -e - Thermocouple E3, 1 1 .6 m east -»— Thermocouple E2, 14.6 m east, outside DC

20

55

50

45 H

p^ 40

2

I

35

i-

-I 1 1 r 15 30 45 60 75 90 105 120

Time (s)

30 -

25

20

Thermocouple W3, 1 1 .6 m west Thermocouple W2, 14.6 m west, outside DC

- »-p Q-^-o-Q-o- 0-0

1 1 1

1 r 15 30 45 60 75

Time (s)

T

90 105 120

Figure 28. Hot gas flow results for 1.5 m diameter test with draft curtains.
3 Warm Climate -15 m Facility 71

720

2.0

1.5 -

1.0 -

0.5 -

0.0

Test 5, 2.0 m pan, CJ Velocity, Vj

Test 7 , 2.0 m pan, CJ Velocity, Vj No draft curtain

600 720

Figure 29. Ceiling jet velocities measured 6. 1 m north and east of fire center for 2.0 m

diameter experiments.
72 3 Warm Climate -15 m Facility

inferred to be the same as the heat released from test 6b based on the similar temperatures measured in the two fire plumes.) Additional data including the mass loss rate for each test and test durations are shown in Table 16. Also, the measured mass loss including steady state linear fit is shown graphically

in Figure 25

The burning rate increased during the early part of the fire until steady state burning was reached.

Tests conducted without the load platform utilized temperature profiles, similar to those shown in the

previous figures, to determine a steady state time range. The values for steady state time are show in the Table 16. The time required to reach steady state varied with pan size with the larger pans requiring more time to achieve steady state.

Ejfect of Open Door on Behavior of Fire

A single open door test was conducted using the 2.0 m diameter pan and JP-5 fuel in order to study the

effects of wind on the fire and the detection of the fire by the ceiling mounted smoke and heat detectors

and the UV/IR detectors mounted on stands on the floor. The hangar doors on the NW, SW, NE, and

SE sides relative to the hangar were opened distances of 14.3 m, 14.5 m, 8.5 m, and 8.4 m,

respectively, in order to present a nearly symmetric opening. Immovable doors of width 9.9 m,

located on either side of the N-S center line through the fire, provided wind blockages along the center

line as shown in Figure 30. Wind speed and direction meters were located 10.4 m, 18.3 m, and 25.9

m (Wl, W2, and W3) from the fire pan center along the center line north of the fire. The

anemometers were all located 3.0 m above the hangar floor. A total heat flux gauge to monitor

radiation from the flame was located 5.1m from the fire center in the west direction and was at a

height of 0.9 m above the floor. UV/IR detectors were positioned in a line at 21 m, 30 m, 37 m,

43 m, 49 m, 55 m, 61 m, 64 m, 67 m, and 70 m from the fire in the NE direction.

At the start of the test, the wind was very light with only anemometer, Wl, measuring a wind speed of

2.3 m/s. The wind speed increased rapidly during the first 30 s of the test reaching maximum values of

8.0 m/s for Wl with speeds of 3.5 m/s recorded for W2 and nearly 8.0 m/s for W3 as shown in Figure

31. The wind direction for all three measurements was about 30 " west of north. This wind direction

remained constant over the entire test. Video observations of the flame during this time show initial flame lean slightly to the south but by the time of maximum wind speed, the flame was estimated to be

leaning 60 ° to the south with only a slight eastward lean. The wind then decreased over the next 20 s to 30 s with speeds dropping to nearly 4.0 m/s. Video footage indicated that the plume straightened

significantly with the southward lean reducing to about 15 ° during this time. A second wind gust then

occurred at about 70 s which produced wind speeds of about 8.0 m/s as measured by Wl. The flame was estimated to lean 80 " to the south during this period and also had a lean of about 45 ° to the east. Comparison with a correlation of flame lean versus wind speed by the American Gas Association [1 1] showed good agreement (i.e., within 3 %) with the observed leans. According to the correlation, a wind speed of 8.0 m/s would be expected to produce about an 81 ° flame lean. The doors were closed

at about 110 s into the test.

A comparison of pairs of thermocouples at 6.1 m in the N-S and E-W planes show the expected

asymmetry in temperatures with the high temperatures in the south and east directions correlating with

the wind gusts as shown in Figure 32. Temperatures at the ceiling in the south and east directions are

fairly constant from plume center to 8.5 m from the fire center and do not reach values required to activate any of the sprinkler heads. The radiometer measured a peak flux of about 6.3 kW/m^ during
3 Warm Climate -15 m Facility 73

the time between the wind gusts when the flame was nearly vertical, as shown in Figure 33. Assuming

a heat release rate equivalent to what was measured for the closed door 2.0 m test (i.e., 6.4 MW) and

assuming a radiative fraction equal to 0.3, a flux level of 5.8 W/m^ would be expected from a point

source. Mass loss rate was not available.

The time of activation of the smoke detectors reflect the observed wind direction. The first detectors to activate were the south detectors. The detectors in this direction responded out to 11.6m within the

first 34 s of the test. Only after the first wind gust had subsided, the north detectors at 3.0 m and

6.1 m activated within 47 s from the start of the test. Activation of the smoke detectors in the east and

west direction remain fairly symmetric. The detectors in the east direction at 3.0 m and 6.1m both

activated at 39 s while the west detectors at 3.0 m and 6. 1 m activated at 38 s and 42 s respectively.

The UV/IR detectors were gated to provide count rates every 0.1 s during the fire. Figure 34 shows

the UV (upper graph) and IR (lower graph) count rate as a function of time. The detector shown in the

figure is located 21.3 m from the pan. There are two substantial decreases in UV emission shown in these figures, one at about 55 s and the other at about 80 s into the test. The fire was estimated to start at about 12 s from time zero in these figures based on the increase of the infrared signals reducing the

55 s and 80 s times to 43 s and 68 s respectively. The IR detector also shows similar, but smaller

drops in signal during these periods. A comparison of IR and UV count rate versus detector distance

reveals that both count rates decay as the inverse square of the distance from the fire center.

The temperature measured at 9.1 m above pan center can be used to determine when the flame leans as a function of time. When the temperature recorded by this thermocouple is high, the flame is more

upright. Lower temperatures suggest a flame which is strongly leaning due to the wind. Figure 35

provides this temperature profile which implies that the flame is showing substantial lean during the

periods between 35 s and 45 s and again at 70 s to 80 s which correlates with the decrease in UV

signal. Note that these times are corrected from the figure for the 12 s delay in fire start. If the bulk

of the UV emission were being produced by the upper portion of the flame, the fact that the flame leans

away from the detectors during this time would explain the decrease in UV emission. Another

explanation could be that with the flame leaning, there is more soot to absorb the UV emission, thus

causing lower net UV flux directed toward the detectors.
74 3 Warm Climate -15 m Facility

97.8

73.8

o

oQ

111 8.4

o

oQ

111

Note: All dimensions in meters

Typical door heigth = 9.75 m (32 ft.)

14.3

1

9.9

^r

9.9

i

8.5

i

Figure 30. Layout for 2.0 m open door fire test in 15 m high facility.
3 Warm Climate -15 m Facility 75

11

10

-§ 6

D

(U

0)Q.

(O? 5

—•— Wind Gauge #1 , 1 0.4 m north — - Wind Gauge #2, 18.3 m north —»— Wind Gauge #3, 25.9 m north

-30 30 60 90

Time (s)

120 150 180

Figure 31. Wind speed measurements for 2.0 m open door fire test.
76 3 Warm Climate -15 m Facility

-30 30 60 90

Time (s)

120 150 180

Figure 32. Temperature measurements for 2.0 m open door fire test.
3 Warm Climate -15 m Facility 77

180

Figure 33. Total heat flux measurement for 2.0 m open door fire test.
78 3 Warm Climate -15 m Facility

180

180

Figure 34. UV and IR emission counts for detector at 21 .3 m during open door fire test.
3 Warm Climate -15 m Facility 79

70 -

60

O^ 50

9>S

0)GLE

0)

40 -

30

20

—•— Thermocouple C1, Center, 0.15 m below ceiling —• - Thermocouple C12, center, 6.1 m below ceiling

-30 30

1^ 60 90 120 150 180

Time (s)

Figure 35. Temperatures along plume center for 2.0 m diameter pan open door fire test.
80 3 Warm Climate -15 m Facility

3.4 Response of Detection and Sprinkler Activation Systems to Fires

The numerous detection systems and sprinkler heads that were installed during the fires described in the

previous two sections were greatly affected by the fire size and conditions under which the tests were

run. In section 3.4, the activation times of the sprinklers and the response of the specific detection

schemes to the heat, smoke, and radiation produced by the fires are described.

3.4.1 Sprinkler Activation Times

The spacing and installation of the automatic sprinklers installed in the 15 m facility were previously

described, Figure 7. The sprinkler response analysis includes the number and type of sprinklers

activated, response times, effect of draft curtains, threshold fire sizes for sprinkler response, effects of

thermal element, and the conductive heat transfer effects of wet-pipe versus dry-pipe sprinkler

configurations.

No sprinkler heads activated during tests 1,2, 3, 11 or 12, where the heat release rate was below 2

MW and the pool size was under 1 m (i.e., the "detector fires"). Test 4, which was the 1.5 m diameter

pan fire with a heat release rate of 2.8 MW, also did not activate any sprinklers.

Tests 5, 6b, 7 and 8 did activate sprinklers in the 15 m hangar. Table 20 shows the response times of

all the sprinklers which activated in these four experiments. The 2.0 m diameter pan fires with heating

rates ranging from approximately 5.6 MW to 6.8 MW, were the smallest size fires to activate any

automatic sprinklers. The 2.5 m diameter pan fires (tests 6b and 8), which produced estimated heat

release rates of 7.7 MW also activated a number of 79 "C to 93 "C automatic sprinklers. None of the

141 °C sprinklers activated in any of the full-scale tests in the 15 m facility. It should be noted that the

maximum ceiling temperatures for test 6b and test 8 exceeded 141 °C; hence, the only reason the

sprinklers did not activate for these tests was that they were not located in the high temperature gas for a long enough period of time.

Test 13 was also a 2.0 m diameter pan fire, but was conducted with the hangars doors open. Due to the severe plume lean this test was terminated at 150 s. No sprinklers activated prior to the test termination.

Analysis of Table 20 shows that for test 5, only one sprinkler activated in the center plume region,

compared to four sprinkler activations in test 7. One possible cause for this is that test 5 exhibited a

fire whirl type phenomenon where the swirling flame moved back and forth across the surface of the

fuel, causing temperature fluctuations at the ceiling. The whirl phenomena also caused the high

temperatures at the ceiling to be more localized in space than for a normal plume. A second cause is the time history of the ceiling temperature. Between 190 s and 330 s, when there were no whirls, the

ceiling temperature dropped below 80 °C, which would delay link activation.

Effects ofDraft Curtains

There are three aspects which can be examined to determine the effects of the draft curtain with respect

to sprinkler response. They are: number of sprinklers activated, response times and the distance from

plume centerline at which sprinkler activation occurred. In this analysis, only similar fire sizes can be

compared. Thus, test 5 (2.0 m diameter pan with the draft curtain in place) is compared to test 7
3 Warm Climate -15 m Facility 81

Table 20. Sprinkler activation times, seconds . n=no activation, *=no sprinklers installed

Test

Sprinkler Location

Sprinkler Type (see Figure 7)

A B C D E F G H I

its 2m

6.7

MW

center n n n n n 182 n n n

3.1 m radius N,S

E,W

n, n

n, n

192, 196

n, n

n, n

n, n

n, n

n, n

n, n

n, n

199, 206

138, n

* * *

6.1m radius N,S,

E,W

n,n

n,n

395, n

199,n

n,n

n,n

n,n

n,n

* * * * *

8.5 m rad. N,S n, n n, n

* * * * * * *

9.1 m rad. E,W n, n n, n

* * * * * * * 11.6m rad. E,W n, n n, n

* * * * * * *

#6b

2.5 m

1.1

MW

center n 78 n n n 91 94 321 n

3.1 m radius N,S,

E,W

n,n

n,n

n,88

147,104

n,n

n,n

n,n

n,n

n,n n,n

107,100

137,100

* * *

6.1 m radius N,S,

E,W

n,n

n,n

144,140

251,207

n,n n,nn,n

n,n

* * * * *

8.5 m radius N,S, n,n 295,247 * * * * * * *

9.1 m radius E,W n,n n,439 * * * * * * *

11.6 m rad. E,W n,n n,n * * + * * * *

#7

2m

5.6

MW

center n 481 n n n 313 582 528 n

3.1 m radius N,S,

E,W

n,n n,n585,n

n,403

n,n

n,n

n,n

n,n

n,n

n,n

545,n

n,383

* * *

6.1m radius N,S,

E,W

n,n

n,n

n,n n,n

n,n

n,n

n,n n,n

* * * * *

8.5 m radius N,S n,n n,n * * * * * * *

9.1 m radius E,W n,n n,n * * * * * * *

11.6 m rad. E,W n,n n,n * * * * * * *

#8

2.5 m

center n 311 n n n 311 342 n n

3.1 m radius N,S,

E,W

n,n

n,n

366,366

359,403

n,n

n,n

n,n

n,n

n,n n,n379,389

338,379

* * *

6.1 m radius N,S,

E,W

n,n n,n

467,n

n,n

n,n

n,n

n,n n,n

* * * * *

8.5 m radius N,S n,n n,n * * * * * * *

9.1 m radius E,W n,n n,n * * * * * * *

11.6 m rad. E,W n,n n,n * * * * * * *
82 3 Warm Climate -15 m Facility

(2.0 m diameter pan without the draft curtain). Similarly, test 6b (2.5 m diameter pan with the draft

curtain in place) is compared to test 8 (2.5 m diameter pan without the draft curtain). In both tests 5

and 7, eight of the 65 sprinklers activated. In this comparison, although the number of sprinklers

activated was the same, the response times were significantly different. In test 5, the first sprinkler

activation occurred in 138 s compared to 313 s for the first sprinkler activation in test 7. A comparison

of Figure 36 with Figure 37 shows a much faster sprinkler response time with the draft curtain in place.

The faster activation for test 5 may have been caused by the fire whirl which produced higher

temperatures than in test 7.

These figures show the ability of the draft curtain to confine the heat released by the fires and limit its spread across the ceiling. Without the draft curtain, the heated gases spread across the ceiling and were cooled below the sprinklers' activation temperatures.

The effects of the draft curtain were also clearly evident in the larger, 2.5 m diameter pan fires. In test 6b, 18 sprinklers activated compared to 12 sprinklers in test 8. This shows that 50% more sprinklers

activated with the draft curtain in place. Comparing Figure 38 with Figure 39 shows much faster sprinkler response times with the draft curtain in place. In test 6b, the first sprinkler activated in 78 s compared to 311 s in test 8. Further analysis also shows with the draft curtain in place a significant

increase in the number of sprinkler activations outside the plume. For these tests, both plumes were

normal arid the peak plume temperatures were similar. The measured differences in sprinkler

activation were probably due to the presence of the draft curtains. In a typical military aircraft hangar,

these heads would provide possible cooling of adjacent aircraft.

Effects of Ceiling Configuration

The ceiling is comprised of 0.25 m (10 inch) I-beams which run north to south across the width of the

hangar, spaced 4.1 m (13.5 ft) on center. The sprinkler deflectors were installed approximately 0.30 m

to 0.36 m below the ceiling deck which placed the deflectors below the I-beam obstructions.

To examine whether the I-beam configuration affected sprinkler response times, it is important to compare the response times of the sprinklers along the north/south axis to those along the east/west axis

to determine if the I-beams channeled the heat. An analysis of Table 20 indicates that the ceiling

configuration had no perceivable effect on the sprinkler response times.

Effects of Fire Size

The experimental fires were designed to determine the threshold fire sizes needed to activate a variety

of sprinklers, with the primary focus on the 79 °C and 141 °C heads. The threshold fire size needed to activate the 79 °C sprinklers in the 15 m hangar was the 2.0 m diameter pan fire which produced a

heat release rate of approximately 6.8 MW. The 2.5 m diameter pan fire which produced a heat

release rate of approximately 7.7 MW was the largest fire conducted in the 15 m hangar. Ceiling

temperatures in the 7.7 MW fires did reach the activation temperature of the 141 °C sprinklers, but were not maintained at that temperature long enough to cause sprinkler activation. Figures 40 and 41

show the effects of fire size on ceiling temperature and sprinkler response in the 15 m hangar. Fire

size affected both the number of sprinklers that activated as well as the response times. Since the draft curtain has a profound impact on the response times of the sprinklers, studying the effects of fire size is accomplished by comparing test 5 to test 6b, and test 7 to test 8.
3 Warm Climate -15

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Effects of Thermal Element

Two factors were analyzed with respect to the thermal element of the automatic sprinklers. The first was the temperature rating of the sprinkler heads used (i.e., 79° C, 93° C, 141° C, and 182° C). The

second was the response time index (RTI), which for this analysis focused on quick response versus

standard response heads. The 79 °C heads responded faster than the 93 °C heads as expected; no

141° C or 182° C heads activated. In general, the lower RTI heads responded more often than the

standards, however, the limited number of comparisons between sprinklers with the same temperature

ratings but different RTIs are insufficient to quantify how much more quickly the quick response

sprinkler head would normally operate.

For the examination of the effects of the RTI, the response of the 79 °C standard response sprinkler was

compared to that of the 79 °C quick response sprinkler. Again, the limited data in the 15 m

experiments make it difficult to draw any definite conclusions. However, analysis of test 6b shows that the 79 °C quick response sprinkler at plume center responded in 78 s compared to 321 s for the 79 °C

standard response head at the same location. This issue is also readdressed in section 4.

Effects of Wet- vs. Dry-Pipe Sprinklers

In order to determine the conductive heat transfer effects of wet-pipe versus dry-pipe sprinklers, the

average response times of similar sprinklers were examined. Table 21 shows the average response

times for the 79 °C QR (wet) and the 79 °C QR (dry) sprinklers located 3.1m from the plume

centerline.

Table 21. Average response times (s) of wet-pipe and dry-pipe sprinkler configurations

Test Number 79° C QR-Wet (s) 79 °C QR-Dry (s) % Difference

5 194 181 6.7

6b 113 111 1.7

7

8

495

374

464

371

6.3

0.8

As shown in the above table, the wet-pipe versus dry-pipe configuration used in these experiments had

no significant effect on the response time of the automatic sprinkler heads. However, any dry-pipe or

pre-action sprinkler system will incur an additional time delay in delivering water from the alarm check

valve assembly to a fused sprinkler head. A few seconds faster activation of automatic sprinkler heads

in a dry-pipe or pre-action configuration will be overshadowed by the time delay (e.g., up to 60 s) at the alarm valve.

3.4.2 Response of Projected Beam Smoke Detectors

Fire tests conducted in the 15 m high facility provided information relative to the response of projected

beam smoke detectors as a function of location, sensitivity settings, window settings, and spacing. The

projected beam detectors were installed parallel to the ceiling at three different elevations. (Refer to Table 5 and Figure 12.) Discussion of their behavior during the test program is divided between the

"detector fire" (less than 2 MW) and the "sprinkler fire" experiments (greater than 2 MW).
90 3 Warm Climate -15 m Facility

Fires less than 2 MW (tests 1-3, 11, 12)

Small ( < 2 MW) test fires were used to determine the response characteristics of the projected beam

smoke detectors. The detector response times for these smaller fires are listed in Table 22. Detectors were set for an alarm sensitivity of 30% signal loss, with an alarm window setting of 30 s, unless

otherwise noted.

Table 22. Response times (s) of projected beam detectors for test fires less than 2 MW

Test Information

Testj^ Pan Size,

m

Sensor Number

Bl B2 B3 B4 B5 B6 B7 B8 B9

IP

12^

0.3x0.3

0.6x0.6

0.9x0.9

0.3x0.3

95 75 92

108 73 89

0.6x0.6 92

136

71

T

NA"

504"

151

51

54

53*'

29"

140

66

T

NA"

554"

NA

NA

NA

637^

244*^

NA

NA

97

653"

241-^

NA

NA

NA

647=

225=

NA - Detector did not activate

* No draft curtain. Alarm sensitivity setting, 20%, alarm window time, 5 s.

'^ Alarm sensitivity setting, 50%, alarm window time, 30 s. Alarm sensitivity setting, 50%, alarm window time, 10 s.

= Alarm sensitivity sefting, 50%, alarm window time, 5 s. T = trouble condition

For the 0.3 m x 0.3 m pan fire with the draft curtain, the three detectors at the highest elevation (0.3 m

below the ceiling) responded within 95 s. In the same test, the three detectors located 2.7 m below the

ceiling alarmed between 136 s and 151 s. The detectors located 5.8 m below the ceiling did not

activate. Note, the detectors located 5.8 m below the ceiling were below the bottom edge of the draft curtain which had a depth of 3.7 m. For the 0.6 m x 0.6 m pan fire with the draft curtain, the three

detectors at the highest elevation went into trouble. A thick layer of smoke quickly developed which

caused nearly complete obscuration of transmitter beam, thus producing a trouble condition. The three

detectors located 2.7 m below the ceiling alarmed between 51s and 71 s. The detectors located 5.8 m

below the ceiling did not activate. While the smoke was not entirely confined by the draft curtain, the

ceiling volume of the hangar outside the draft curtain prevented the smoke layer from dropping to 5.8 m where those detectors would activated.

For the 0.9 m X 0.9 m pan fire with the draft curtain, the three detectors at the highest elevation went

into trouble. Of the three detectors located 2.7 m below the ceiling, only the detector over the center of the plume alarmed, while the two detectors 7.0 m off center went into trouble. Of the three

detectors located 5.8 m below the ceiling, only the detector over the center of the plume alarmed, while

the two detectors 7.0 m off center did not activate.
3 Warm Climate -15 m Facility 91

The 0.3 m X 0.3 m and 0.6 m x 0.6 m pan fires were repeated without the draft curtain to determine

the effect of the draft curtain on the smoke layer development and the response characteristics of the

detectors for the 0.3 m x 0.3 m pan fires. Comparing the operation with and without draft curtains

showed no significant difference in response time for the detectors at the highest elevation. These

detectors were near the ceiling (i.e., 0.3 m below), and smoke filling at this level was independent of

the draft curtain. However, for the three detectors located 2.7 m below the ceiling, only the detector over the center of the plume alarmed without the draft curtain in place. The center detector, B5, went

into alarm after 53 s. The two detectors located 7.0 m off center never activated, even though their

sensitivity and alarm window settings were adjusted to provide faster response. This clearly shows that without the draft curtains, the smoke progressed along the ceiling and did not bank down enough to activate these outer detectors.

Also, for the comparison of the 0.6 m x 0.6 m fire with and without the draft curtain, no significant

difference in response time was observed for the detectors at the highest elevation. Of the three

detectors located 2.7 m below the ceiling, the detector located over the center of the plume alarmed in 29 s. However, the two detectors located 7.0 m off center showed a significant delay in response time even though their sensitivity was increased. This again demonstrates the effect of the draft curtain.

Note, for the 0.3 m x 0.3 m and 0.6 m x 0.6 m pan fires without the draft curtain, detectors B7, B8

and B9 were relocated as described earlier.

Fires greater than 2 MW (tests 4 - 8, 13)

For the JP-5 fuel fires with heat outputs greater than 2 MW, results from projected beam smoke

detectors are presented in Table 23. For all tests the detectors at the highest elevation all went into a

trouble state. This is attributed to the rapid development of high density smoke within the draft

curtained area. Consistent with current installation practices [21], the alarm window for these detectors was set at 30 s,. Analysis of the actual detector signal shows that these detectors could have produced

alarm conditions if they were adjusted to be less sensitive, yet faster to respond.

Detectors located 2.7 m below the ceiling consistently lilarmed within a range of 22 s to 200 s. The

only exception was in test 4 where these detectors sensed a trouble condition. Once again, the

detector's sensitivity setting was 20 % and alarm window was set at 30 s for test 4. Subsequently, the

alarm window was decreased to 5 s and the sensitivity was increased from 30% to a 20% signal loss threshold. The response times in the Table 23 indicate consistent activation for this set of detectors.

In most cases, detector B5, located along the centerline 2.7 m below the ceiling, went into alarm nearly

30 s before the fuel pan was fully involved with flame. (Time to full involvement of the fuel pan was

extracted from video tape footage and observations made during the tests.) The detectors located 5.8 m

below the ceiling (2.1 m below the draft curtain) responded somewhat inconsistently. For the 1.5 m

diameter pan fire with the draft curtain, the center detector alarmed in 143 s. A trouble condition

occurred for the 2.0 m and 2.5 m diameter pan fires. Without the draft curtain, this detector alarmed in 646 s for the 2.0 m diameter and then reported a trouble condition for the 2.5 m diameter pan fire. The

two outer detectors, located 7.0 m off center responded sporadically. Since the smoke plume leaned

significantly in some cases, detectors in the direction the plume was leaning generally responded faster.

From the data, it can be seen that with draft curtains, the detectors located at 2.7 m below the ceiling

responded faster than those in similar fires without draft curtains. The exception in this case is the
92 3 Warm Climate -15 m Facility

center detector at 2.7 m below the ceiling. This detector showed no significant change throughout the

series. However, the two detectors located 7.0 m off center alarmed much faster with the draft curtain.

For example, in test 5 (2.0 m dia. pan, w/ draft curtains), detector B4 went into alarm at 39 s, whereas

in test 7 (2.0 m dia. pan, w/o draft curtains) the same detector alarmed in 152 s. Similarly, in

comparing tests 6b and 8, detectors B4 and B6 went into alarm at 32 s and 31s, but for the latter test they did not alarm until 175 s and 200 s respectively.

Table 23. Projected beam detector response times (s) for test fires greater than 2 MW

1 csi in

Test# Pan Size

(m)

Bl B2 B3 B4 B5 B6 B7 B8 B9

4 1.5 dia. T T T T T T NA 143 448 ::g

308

566

5 2.0 dia. T T T 39" 25" 39" 88 T

2,5 dia. 't T T

' ':•:" 31" 32" .22" 84 'T

T 2.0 dia. T T T 152" 22" 46" 521 646 552

50^

.::::::.:J':::::::::::::::::

13''"'

2.5 dia.

2.0 dia.

,...,..„.. X.....:...,. T ............x,. 175"

47"

24"

39"

200"

27"

530 T

T T T 55"

NA - Detector did not activate

' Open door test

^ No draft curtain ''Alarm sensitivity setting, 20%, alarm window time, 5 s.

" Alarm sensitivity setting, 50%, alarm window time, 30 s.

'' Alarm sensitivity setting, 50%, alarm window time, 10 s.

' Alarm sensitivity setting, 50%, alarm window time, 5 s. T= trouble condition

Figure 42 shows the response of these detectors for all cases with and without draft curtains. It can be

seen from the figure that the tests without the draft curtain resulted in detector responses, in most cases, much longer than the cases with the draft curtain. Since the draft curtain contains the accumulating

smoke within a defined area, the response time of the outer two detectors (B4, B6) is similar to the center detector. However, in the cases without draft curtain, only the center detector responded with

reasonable certainty.

During the open door test case (test 13), all three detectors responded quickly (i.e., B4 - 47 s, B5 - 39 s, B6 - 27 s). It was observed however, during the open door test, that the flame leaned

substantially and provided a large volume of plume smoke near the ceiling which enhanced the

activation of beam detectors as compared to experiments with no wind and the plume upright.

3.4.3 Response of Photoelectric Smoke Detectors

Photoelectric smoke detectors normally have not been installed in aircraft hangars. However, these

experiments included photoelectric smoke detectors to help determine their response in general high
3 Warm Climate -15 m Facility 93

With Draft Curtain Without Draft Curtain

600

«. 500 -

0)E

$ 400

co

o.

(0

0) 300 -

u

0) ^ 200

100

No Activation Region

R^^^ Detector B4

Detector B5

Detector B6

E E CD (a E E OJ (0 CO CD o T3 CO CD o •o o O E E o . O E E

X X o lO X X o in E E CM CM E E CM CM COd

CD

CD Pan Size

CO

CD

CO

CD

Figure 42. Projected beam detector response for test cases with and without draft curtains,

2.7 m below ceiling.
94 3 Warm Climate -15 m Facility

250

TliTrl I:

HNORTH

EAST DSOUTH

laWEST

3 m 6.1 m 8.5 m 9.1 m 10.7 m 11.6 m 13.7 m

(10 ft) (20 ft) (28 ft) (30 ft) (35 ft) (outside DC)

Distance from Plume Center

(38 ft) (45 ft) (outside DC)

Figure 43. Photoelectric smoke detector response, 0.5 MW fire with draft curtain.

300

HNORTH

EAST DSOUTH

QWEST

3.0 m 6 1 m 8.5 m 9.1 m 10.7 m 11.6 m 13.7 m

(10 ft) (20 ft) (28 ft) (30 ft) (35 ft) Distance from Plume Center

(38 ft) (45 ft)

Figure 44. Photoelectric smoke detector response, 0.5 MW fire w/o draft curtain.
3 Warm Climate -15 m Facility 95

Table 24. Photoelectric smoke detector response times (s) for fires less than 2 MW

Location

3.0 m

(10 ft) 6.1m(20 ft)

8.5 m

(28 ft) 9.1m(30 ft)

10.7 m

(35 ft)

(outside DC)

11.6 m

(38 ft)

13.7 m

(45 ft)

(outside DC)

Test 1 - 0.3 m X 0.3 m pan, JP-5, With Draft Curtain

North —

' — —

East — —

South 753 — — —

West 382 — —

Test 2 - 0.6 m x 0.6 m pan, JP-5, With Draft Curtain

North 27 44 40 — — — —

East 23 35 — 73 — 90 181

South 32 53 48 — — —

West 31 60 — 81 — 90 173

Test 3 - 0.9 m X 0.9 m pan, JP-5, With Draft Curtain

North 33 33 37 — — — —

East 33 37 — 53 — 57 103

South 41 41 41 — 137 — —

West 32 36 — 49 — 70 91

Test 1 1 - 0.3 m X 0.3 m pan, JP-5, Without Draft Curtain

North —

East :.::

South 596 604 — — —

West 504 — —

Test 12 - 0.6 m X 0.6 m pan, JP-5, Without Draft Curtain

North 58 53 58 — — — —

East 61 49 — 153 — 182 170

South 41 49 58 — 116 — —

West 40 57 — 115 — 132 253

detector did not activate —no detector installed
96 3 Warm Climate -15 m Facility

bay applications. This may be useful in evaluating detector response and spacing in other high bay

occupancies. The location of photoelectric smoke detectors in the 15 m high facility is described

earlier and shown in Figure 10.

The spacing of detectors beyond 6.1m from the source of the fire was slightly different along the

north/south axis than the east/west axis due to the location of the draft curtain. The detectors located

8.5 m and 10.7 m from the source were only installed along the north and south axes. The detectors

located 9.1 m, 11.6 m and 13.7 m from the source were only installed along the east and west axes. These distances were selected in order to achieve the most uniform spacing from the edges of the draft

curtain.

Fires less than 2 MW (tests 1-3, 11, 12)

The response times of the photoelectric smoke detectors for fire sizes less than 2 MW are shown in Table 24. For the 0.6 m x 0.6 m pan fires, a comparison of the response times of the detectors at 8.5

m to those at 9.1 m from the source shows that the ceiling configuration (i.e., the direction of the

beams with respect to air flow) was a factor. The detectors at 9. 1 m were perpendicular to the smoke

movement across the roof beams while the detectors at 8.5 m were parallel to the smoke movement

along the beams. The activation of the detectors at 9.1 m occurred approximately 1-1/2 to 2-1/2 times

later than the detectors at 8.5 m. This effect was not evident for any of the larger fires.

Tests 1 and 11 were conducted using the 0.3 m x 0.3 m pans; neither produced sufficient smoke to activate any of the photoelectric smoke detectors prior to 382 s. Tests 2 and 12 were conducted using

the 0.6 m X 0.6 m pans (0.45 MW fire). In test 2, which was conducted with a draft curtain in place,

12 of the 14 detectors within the draft curtain activated sooner than the same detectors in test 12 which was conducted without the draft curtain. This can be seen graphically by comparing Figures 43 and

44. Similarly, the detectors located 9. 1 m (30 ft) from the source in test 2 activated within 81s,

however, the response time of the same detectors in test 12 ranged from 115 s to 153 s. This shows that the draft curtain has a definite effect on detector response time for a fire of this size.

The photoelectric smoke detectors installed in these experiments have a smooth ceiling listed spacing of

9.1m (30 ft). Analysis of the detector spacing for both 0.6 m x 0.6 m pan fires shows that all the

detectors spaced within 6.1m (20 ft) of the fire activated within 61s with or without the draft curtain

in place. This indicates that a detector spacing of 12.2 m (40 ft) would be acceptable for detecting a 0.6 m X 0.6 m JP-5 fire in a 15 m high hangar. This is contrary to the current practice of reducing

detector spacing for high bay areas.

Test 3 was conducted using the 0.9 m x 0.9 m pan with the draft curtain in place. All detectors within

9.1 m (30 ft) of the source activated within 53 s. The ceiling configuration did not have a significant

effect on the activation of detectors for this size fire. The activation of detectors outside the draft

curtain occurred approximately 1-1/2 to 3 times longer than the detectors within the draft curtain. The

spacing of detectors showed no significant difference in the response times of the detectors located 9.1

m (30 ft) from the source compared to those spaced 3.0 m (10 ft) and 6.1 m (20 ft) from the source. Again, this is contrary to the present practice of reducing detector spacing in high bay areas.

Fires greater than 2 MW (tests 4-8, 13)
3 Warm Climate -15 m Facility 97

The response times of the photoelectric detectors for fire sizes greater than 2 MW are shown in Table

25. For these larger tests, the draft curtain did not have a significant effect on the activation time of the

photoelectric detectors. For example, although the detectors outside the draft curtain in test 5 took

longer to activate than the same detectors without a draft curtain in test 7 the actual response time of all the smoke detectors was within 79 s for test 5 and 50 s for test 7. An analysis of the spacing of the

detectors shows no significant difference in the response time of detectors spaced 9.1 m (30 ft) from the source compared to detectors spaced 3.0 m (10 ft) and 6.1m (20 ft) from the source. For example, in

test 6b, the detector located 9.1 m east of the source activated in 31 s while the detector located 3.0 m

east activated in 27 s. In addition, the ceiling/beam configuration had little or no effect on the response

time of the detectors. For example, in test 8, the detector located 9.1m east (where the smoke flow was perpendicular to the roof beams) activated in 38 s, while the detector located 8.5 m north (where

the smoke flow was parallel to the roof beams) activated in 34 s.

3.4.4 Response of Single Point Heat Detectors

The point heat detectors tested in the 15 m high facility were those listed as rate-compensation, fixedtemperature detectors with an alarm threshold of 57.2 °C (135 °F). This alarm threshold would not normally be suitable for a high bay hangar application with relatively high ambient temperatures. This

alarm threshold was chosen as the lowest possible alarm threshold for a hangar application. The

spacing of detectors beyond 6.1m from the source of the fire was slightly different along the

north/south axis than the east/west axis due to the location of the draft curtain.

For fire sizes less than 2 MW, none of the 57.2 °C heat detectors responded, while for fire sizes

greater than 2 MW the 57.2 °C heat detectors did activate. In addition, some of these experiments also

activated 79.4 °C automatic sprinklers. In every case where an automatic sprinkler activated, it was

preceded by the activation of a 57.2 °C heat detector.

Test 4, which was a 1.5 m diameter pan fire with a heat release rate of 2.8 MW was the smallest fire size to activate any 57.2 °C heat detector in the 15 m high facility. The first heat detector responded

96 s after ignition. That detector was located 3.0 m east of the fire's centerline, and its activation

corresponded to the plume lean. The overall detector response time ranged from 96 s to 551 s. Only

10 of the 17 heat detectors activated during this experiment, and none of the detectors outside the draft

curtain activated. This fire size appeared to represent the lower threshold with respect to heat detector

activation in the 15 m high facility.

Test 13 was conducted with the doors open. Due to the severe plume lean this test was terminated at 150 s. No heat detectors activated prior to test termination. This result is consistent with the

thermocouple measurements which indicated temperatures below 57 "C for most of the time during the

test.

The response times of the heat detectors for all fire sizes greater than 2 MW are shown in Table 26.

Effects ofDetector Spacing

In test 5, the average response time of the detectors located 3.0 m from fire center was 79 s, compared
98 3 Warm Climate -15 m Facility

Table 25. Photoelectric smoke detector response times (s) for fires greater than 2 MW

Location

3.0 m

(10 ft) 6.1m(20 ft)

8.5 m

(28 ft) 9.1m(30 ft)

10.7 m

(35 ft)

11.6 m

(38 ft)

13.7 m

(45 ft)

Test 4 - 1.5 m diameter pan, JP-5, With Draft Curtain

North

South

West

25

17

26

21

30

22

26

29

38

30

29

38

75

38

46

67

58

Test 5 - 2.0 m diameter pan, JP-5, With Draft Curtain

North

East South

West

33

29

25

29

33

37

42

29

42

37

42

41

79

50

45

71

54

Test 6b - 2.5 m diameter pan, JP-5, With Draft Curtain

North

East

South

West

27

27

18

38

27

31

23

42

31

27

31

46 51 55

Test 7 - 2.0 m diameter pan, JP-5, Without Draft Curtain

North

East South

West

30

29

25

21

30

37

30

29

33

34

42

37

38

46

37

50

41

Test 8 - 2.5 m diameter pan, JP-5, Without Draft Curtain

North

East South

West

26

25

26

25

29

34

29

33

34

29

38

37

42

42

41

46

50

Test 13 - 2.0 m diameter pan, JP-5, Without Draft Curtain, Open Door

North

East South

West

47

39

26

38

47

39

30

42

51

30

51

46

34

56

51

56

55

detector did not activate —no detector installed
3 Warm Climate -15 m Facility 99

to 94 s for the detectors located 6.1m from fire center. In test 6b, the average response time of the

detectors located 3.0 m from fire center was 60 s, compared to 57 s for the detectors located 6.1m

from fire center. In test 7, the average response time of the detectors located 3.0 m from fire center was 103 s, compared to HI s for the detectors located 6.1 m from fire center. In test 8, the average

response time of the detectors located 3.0 m from fire center was 53 s, compared to 65 s for the

detectors located 6.1 m from fire center.

Analysis of the 57 °C heat detectors in the 15 m hangar indicates no significant difference in the

average response times for the detectors installed 6.1 m from the fire as compared to those installed

3.0 m from fire center. Detectors installed 3.0 m and 6. 1 m from fire center actually represent a spacing of 6.0 m and 12.2 m between detectors. Consequently, in the 15 m hangar, the response of

these heat detectors to a jet fuel spill fire shows that the detectors could be installed at a spacing of 12.2

m (40 ft) without adversely affecting response times.

Effects ofDraft Curtains

Figures 45 and 46 graphically represent the response times of the 57 °C heat detectors in tests 6b and 8

respectively. As shown in Figure 45, the average response time for the detectors located 9. 1 m from

the fire was 51s with the draft curtain in place. By comparison, Figure 46 shows the average response

time for the detectors 9.1m from the fire to be 111 s without the draft curtain. Further analysis of the

detectors located 1 1.6 m from the fire shows an average response time of 79 s with the draft curtain in place compared to 182 s without the draft curtain.

Figures 45 and 46 also illustrate the ability of the draft curtains to confine the heat and limit its spread

across the ceiling. To illustrate this point, note that in Figure 45 the detectors outside the draft curtain

(at 13.7 m from the fire) had an average response time of 384 s. By comparison, the same detectors in Figure 46 (without the draft curtains) had an average response time of only 207 s.

With the draft curtain in place, the detectors inside the draft curtain activated sooner than the same

detectors with the draft curtain removed. The detectors installed beyond the limits of the draft curtain

activated sooner when the draft curtain was removed.

Effects of Ceiling Configuration

The I-beams which directly support the roof run along the north/south axis. Consequently, the heat

detectors installed along the north/south axis were run parallel to these beams, while the detectors

installed along the east/west axis were perpendicular to them. An analysis of Table 26 indicates no

systematic variations due to the orientation of the I-beams.
100 3 Warm Climate -15 m Facility

Table 26. 57.2 °C Heat detector response times (s) in 15 m high facihty

3.0 m 6.1m 8.5 m 9.1m 10.7 m 11.6 m 13.7 m

(48 ft) (outside DC)

Location (10 ft) (20 ft) (28 ft) (30 ft) (35 ft) (38 ft) (outside DC)

Test 4 - 1.5 m diameter pan, 2.8 MW fire, with draft curtain

North 463 526

East 96 184 551 —

South 197 247 397 — — —

West 217 521 - -

North

Fast

92

71

96

88

154

121 —

144 371

South 80 92 113

West 71 100 175 196 375 :;|

Te;st 6b - 2.5 m diameter pan. 7.7 MW fire with draft curtain

North 65 65 69 — — —

East 69 27 69 85 365

South 19 65 65 }M:^m^mz-^ 377 — —

West 85 69 — 32 — 73 402

Test 7 - 2.0 m diameter pan, 5.6 MW fire without draft curtain

North

East

188

75

92

138

200

274 —580 584

South

West

84

63

101

113

138 201

303

^ gg^---|;

167 —

Test 8 - 2.5 m diameter pan, 7.7 MW fire without draft curtain

'''North''

''

East

South

West

' 59

51

51

51

59

59

67

75

105

92

96

125

:::::::::::::::::::::|^:.:::V:.::,:.::::':::: 201

163

201

213

Test 13 - 2.0 m diameter pan, open door fire without draft curtain

North

East

South

West

—

_,.,:: :::.::.:: :::::>:::::::::::^.'.:

detector did not activate — no detector installed at this location
3 Warm Climate -15 m Facility 101

600

500

400

300

200

100

3.0 m 6.1 m 8.5 m 9.1 m 10.7 m 11.6 m 13.7 m

(10 ft) (20 ft) (28 ft) (30 ft) (35 ft) (outside DC)

Distance from Plume Center

(38 ft) (48 ft) (outside DC)

'NORTH

'east ^SOUTH

^WEST

Figure 45. Response of 57 °C heat detectors to 7.7 MW fire conducted in 15 m high

facility with draft curtains.

rngnlTI

(10 «) (20 ft)

8.8 m 9.1 m 10.7 m

(28 ft) (30 ft) (36 ft) DIstanc* from Plum* Canter

11.6 m

(38 ft)

NORTH

east

DSOUTH

tt^an(48 ft)

Figure 46. Response of 57 °C heat detectors to 7.7 MW fire conducted in 15 m high

facility without draft curtains.
102 3 Warm Climate -15 m Facility

3.4.5 Response of Optical Flame Detectors

The settings, configuration and mounting height of the combination UV/IR optical detectors were

discussed earlier, with the exact location of the detectors shown in Figure 14. The effects of ceiling

height and draft curtains were not evaluated for these detectors since UV/IR detectors respond to the

flame and not smoke or heat. The physical dimensions of the 15 m hangar permitted detectors to be

located a maximum distance of 70.1 m from the fire center. The optical flame detectors were evaluated

for each fire size. The fire experiments were designed to evaluate the response thresholds to the

detector fires and to the sprinkler fires.

There are three significant facts regarding the controller settings and the physical location of the

detectors that warrant further discussion. First, because the experiments included a variety of fire sizes, detectors were positioned in five different configurations. Second, the UV/IR controller settings were varied for the 2.0 m and 2.5 m diameter pan fires. These controller settings are shown in Table

6. The main effect of changing the controller settings was to increase or decrease the detector's range.

The controller setting of 0.25 s gate length, 2 counts per gate, and 3 consecutive gates (0.25/2/3)

requires a minimal signal strength of 6 counts occurring in 0.75 s to reach alarm state. This equates to a count per second (CPS) rate of 8 CPS for 1 s from both the UV and IR portions of the detector. The

controller setting of 0.25 s gate length, 4 counts per gate, and 4 consecutive gates (0.25/4/4) requires a

signal strength of 16 CPS for 1 s to reach alarm state. This equates to a rate of 16 CPS fori s from

both the UV and IR portions of the detector.

The third factor involves the manner in which the optical flame detectors were aimed during these tests. All experknents were conducted with the optical flame detectors positioned such that each detector had

a direct line of sight to the fire source. This effectively means that the fuel pan was directly in the center of each detector's cone of vision which would yield the detector's optimum response.

Consequently, the test results here represent the best case response scenario for the optical detectors.

Fires that occur within the detector's cone of vision, but not directly along the centerline axis will have

slower response times and shorter threshold response distances. The response characteristics will

decrease proportionally as the viewing angle increases towards the maximum listed viewing angle of

the detector.

General Analysis

The raw CPS data files compiled by Detector Electronics Corporation were examined for response time

from three distinct events: ignition, full pan involvement, and steady state burning. The application of

these three response time milestones for each detector yields a representation of threshold response

distances to a variety of fire sizes and at various stages during each fire. The data is presented in this format to aid design engineers in determining when and at what distance these optical detectors will

respond to a growing fire in an aircraft hangar.

For the purpose of analyzing this data, ignition is defined as the time that self-sustained combustion was

achieved. Full pan involvement was determined by visual observation, and was considered to be the

time at which the flame front completely covered the fuel surface. The time to steady state burning was

calculated using the mass loss measurements recorded by the load cell. Where load cell data was not

available, a conservative estimate of the time to steady state burning was made based on similar size

fires, and by analyzing the steady state infrared signature recorded by the optical detectors.
3 Warm Climate -15 m Facility 103

Table 27. Optical detector response time after ignition for all 15 m high facility tests PAN SIZE (m) FACILITY HRR (MW) TEST No. DETECTOR DISTANCE FROM SOURCE CENTER (m)

.3X .3 15m o.r 1 9.1 10.7 12.2 13.7 15.2 16.8 18.3 21.3 30.5 48.8

Controller: FULL PAN:.25/2/3 5sResponse Time (s) ST STATE: 120 sN/A^ N/A^ N/A^ N/A- N/A^ N/A^ N/A^ N/A^ N/A^ N/A^

.3X.3 15m o.r 11 12.2 15.2 18.3 21.3 24.4 27.4 30.5 36.6 42.7 48.8

Controller: FULL PAN:.25/2/3 5s

Response Time (s) ST STATE: 150 s

9.1 25.0 NR NR NR NR NR NR NR NR

.6x .6 15m 0.5 2 21.3 22.9 24.4 25.9 27.4 30.5 33.5 36.6 39.6 48.8

Controller: FULL PAN:.25/2/3 10 sResponse Time (s) ST STATE: 150 s5.5 10.4 10.4 11.7 21.5 18.8 20.8 20.8 67.2 NR

.6x.6 15m n/a 12 12.2 15.2 18.3 21.3 24.4 27.4 30.5 36.6 42.7 48.8

Controller: FULL PAN:.25/2/3 10 sResponse Time (s) ST STATE: 150 s1.5 16.1 25.6 28.6 28.5 28.6 NR NR NR NR

.9x.9 15m 1.9 3 21.3 22.9 24.4 25.9 27.4 30.5 33.5 36.6 39.6 48.8

Controller: FULL PAN:.25/2/3 20 sResponse Time (s) ST STATE: 150 s18.5 18.2 29.2 22.7 21.5 30.8 25.5 33.0 44.5 47.0

1.5 Dia 15m 2.8 4 21.3 30 5 36 6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

Controller: FULL PAN:.25/2/3 30 sResponse Time (s) ST STATE: 180 s24.4 33.0 34.0 36.1 39.8 47.9 72.5 58.2 72.6 93.1

2.0 Dia 15m 6.8 5 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

Controller: FULL PAN:.25/2/3 35 sResponse Time (s) ST STATE: 120 s17.3 23.6 24.8 30.6 33.6 45.2 43.4 41.7 61.6 69.9

2.0 Dia 15m 5.6" 7 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

Controller: FULL PAN:.25/4/4 35 s

Response Time (s) ST STATE: 180 s

17.6 20.6 26.4 31.4 34.8 51.4 NR 61.4 NR NR

2.0 Dia 15m n/a 13 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

Controller: FULL PAN:

.25/4/4 35 sResponse Time (s) ST STATE: 180 sN/A" N/A*- N/A"

OPEN DOOR TEST

N/A" N/A" N/A" N/A" N/A" N/A" N/A"

2.5 Dia 15m l.T 6b 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

Controller: FULL PAN:

.25/2/3 40 s

Response Time (s) ST STATE: 150 s

12.7 18.1 20.8 30.4 33.6 34.6 40.1 38.7 41.3 45.5

2.5 Dia 15m n/a 8 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

Controller: FULL PAN:

.25/4/4 40 sResponse Time (s) ST STATE: 150 s13.3 23.6 28.7 35.7 37.4 39.7 46.7 NR NR NR

a - No optical flame detector responses were recorded during test #1. b - No valid data for optical flame detector responses from ignition were obtained from Test #13. NR - No response from detector. " - Estimated HRR used. NOTE: 1. Response times are measured in reference to elapsed time from "time zero" for ignition response

or from a controller reset for full pan and steady state responses

2. Full Pan and Steady State times are the time to reach that respective state and are measured in reference to "time

zero".
104 3 Warm Climate -15 m Facility

Table 28. Optical detector response time after full-pan involvement for all 15 m tests PAN SIZE (m) FACILITY HRR (MW) TEST No. DETECTOR DISTANCE FROM SOURCE CENTER (m)

.3 X .3 15m o.r 1 9.1 10.7 12.2 13.7 15.2 16.8 18.3 21.3 30.5 48.8

Controller: .25/2/3 Response Time (s) N/A» N/A^ N/A" N/A'' N/A" N/A" N/A" N/A" N/A" N/A"

FULL PAN: 5s ST STATE: 120 s .3x.3 15m O.r H 12.2 15.2 18.3 21.3 24.4 27.4 30.5 36.6 42.7 48.8

1st Reset 48.3 s Response Time (s) 0.3 1.1 NR NR NR NR NR NR NR NR

2nd Reset 67.2 s 0.3 1.9 NR NR NR NR NR NR NR NR

Controller: .25/2/3 FULL PAN: 5s ST STATE: 150 s .6x.6 15m 0.5 2 21.3 22.9 24.4 25.9 27.4 30.5 33.5 36.6 39.6 48.8

1st Reset 106 s Response Time (s) 4.6 0.4 0.4 0.4 8.1 1.6 1.6 6.1 23.9 NR

2nd Reset 140.4 s 4.3 0.3 0.3 0.3 10.8 0.6 0.6 7.8 NR NR

Controller: .25/2/3 FULL PAN: 10 s ST STATE: 150$

.6x.6 15m n/a 12 12.2 15.2 18.3 21.3 24.4 27.4 30.5 36.6 42.7 48.8 :

1st Reset 32.9 s Response Time (s) 0.3 0.3 0.3 0.5 0.8 0.8 2.1 NR NR NR

2nd Reset 56.1 s 0.3 0.3 0.3 0.3 0.3 0.3 5.1 12.1 NR NR

Controller: .25/2/3 FULL PAN: 10 s ST STATE: 150 s .9x .9 15m 1.9 3 21.3 22.9 24.4 25.9 27.4 30.5 33.5 36.6 39.6 48.8

1st Reset 82.4 s Response Time (s) 3.3 0.3 0.3 0.3 3.6 0.3 0.3 0.3 0.3 3.3 2nd Reset 122.1 s 3.3 0.3 0.3 0.3 3.8 0.3 0.3 0.3 0.3 1.3 Controller: .25/2/3 FULL PAN: 20 s ST STATE: 150 s

1.5 Dia 15m 2.8 4 21.3 30.5 36.6 42.7 48.8 54:9 6L6 64.0; 67.1 70.1 :

1st Reset 111.9s Response Time (s) 3.1 0.4 0.3 0.4 1.1 1.9 11.6 11.4 NR NR

2nd Reset 132.3 s 3.3 0.3 0.3 0.3 1.0 1.5 NR NR NR NR

Controller: .25/2/3 FULL PAN: 30 s ST STATE: 180 s 2.0 Dia 15m 6.8 5 "^"2i:3-- 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

1st Reset NO 2nd RESET

108.7 s BEFORE SResponse Time (s) TEADY STATE0.3 0.3 0.3 0.3 0.3 0.3 0.3 10.6 0.3 NR

Controller: .25/2/3 FULL PAN: 35 s ST STATE: 120 s 2.0 Dia 15m 5.6" 7 -mm 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

1st Reset 66.3 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 1.3 1.1 4.3 NR

2nd Reset 86.1 s 0.3 0.3 0.3 0.3 0.3 1.3 4.4 4.4 5.1 NR

Controller: .25/4/4 FULL PAN: 35 s ST STATE: 180 s 2.0 Dia 15m n/a 13 2L3 30,5 36.6 42.7 48. g 54.9 61.0 64.0 67.1 70.1

1st Reset 43.6 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.8 NR NR NR NR

2nd Reset 57.8 s 0.3 0.3 0.3 0.3 9.3 NR NR NR NR NR

Controller: .25/4/4 FULL PAN: 35 s ST STATE: 180 s OPEN DOOR TEST

2.5 Dia 15m 7.7" 6b 21.3 30,5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

1st Reset 61.8 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.8 3.0 5.3 2nd Reset 92.5 s 0.3 0.3 0.3 0.3 0.3 0.5 1.8 0.5 5.3 4.1

Controller: .25/2/3 FULL PAN: 40 s ST STATE: 150 s 2.5 Dia 15m n/a 8 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.11

1st Reset 58.3 s Response Time (s) 0.3 0.3 0.3 0.3 0,3 2.3 4.8 4.8 NR NR

2nd Reset 89.7 s 0.3 0.3 0.3 0.3 0.3 0.3 4.0 3.8 4.0 NR

Controller: .25/4/4 FULL PAN: 40 s ST STATE: 150 s

a - No optical flame detector responses were recorded during test til. NR - No response from detector. " - Estimated HRR used.
3 Warm Climate -15 m Facility 105

Table 29. Optical detector response times after steady-Steady burn rate for all 15 m tests PAN SIZE (m) FACILITY HRR (MW) TEST No. DETECTOR DISTANCE FROM SOURCE CENTER (m) .3X .3 15m o.r 1 9.1 10.7 12.2 13.7 15.2 16.8 18.3 21.3 30.5 48.8

Controller: .25/2/3 Response Time (s) N/A" N/A" N/A" N/A" N/A" N/A" N/A" N/A' N/A" N/A"

FULL PAN: 5s ST STATE: 120 s .3X.3 15m O.r 1 11 12.2 15.2 18.3 21.3 24.4 27.4 30.5 36.6 42.7 48.8

1st Reset 48.3 s Response Time (s) 0.3 1.1 NR NR NR NR NR NR NR NR

2nd Reset 67.2 s 0.3 1.9 NR NR NR NR NR NR NR NR

Controller: .25/2/3 FULL PAN: 5s ST STATE: 150 s .6x.6 15m 0.5 2 21.3 22 9 24. 4 25.9 27.4 30.5 33.5 36.6 39.6 48.8

1st Reset 164.9 s Response Time (s) 3.5 0.3 0.3 0.3 5.3 0.3 1.0 0.3 NR NR

2nd Reset 189.4 s 3.6 0.3 0.3 0.3 5.1 0.3 0.6 0.6 24.8 NR

Controller: .25/2/3 FULL PAN: 10 s ST STATE: 150 s .6x.6 15m n/a 1 12 12.2 15.2 18.3 21.3. 24.4 27.4 30.5 36.6 42.7 48.8

1st Reset 162.8 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 9.6 NR NR

2nd Reset 182.9 s 0.3 0.3 0.3 0.3 0.3 0.3 1.4 NR NR NR

Controller: .25/2/3 FULL PAN: 10 s ST STATE: 150 s .9x.9 15m 1.9 1 3 2L3 22.9 24.4 25.9 27.4 30.5 33.5 36.6 39.6 48.8

1st Reset 151.7 s Response Time (s) 3.3 0.3 0.3 0.3 4.1 0.3 0.3 0.3 1.6 1.6 2nd Reset 166.9 s 3.6 0.3 0.3 0.3 4.1 0.3 0.3 0.8 0.8 4.8

Controller: .25/2/3 FULL PAN: 20 s ST STATE: 150 s

1.5 Dia 15m 2.8 1 4 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

1st Reset 192 s Response Time (s) 3.1 0.3 0.3 0.3 0.3 4.6 14.9 10.9 NR NR

2nd Reset 222.1 s 3.1 0.3 0.3 0.3 0.3 2.1 2.4 13.1 2.3 NR

Controller: .25/2/3 FULL PAN: 30 s ST STATE: 180 s 2.0 Dia 15m 6.8 1 5 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

1st Reset 129.7 s Response Time (s) 3.1 0.3 0.3 0.3 0.3 0.8 3.9 10.9 3.3 NR

2nd Reset 159.7 s 3.0 0.3 0.3 0.3 0.3 0.3 0.8 10.8 0.8 0.8

Controller: .25/2/3 FULL PAN: 35 s ST STATE: 120 s 2.0 Dia 15m 5.6" 1 7 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

1st Reset 189.3 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.8 5.0 NR

2nd Reset 211.5 s 0.3 0.3 0.3 0.3 0.3 0.3 NR 0.3 NR NR

Controller: .25/4/4 FULL PAN: 35 s ST STATE: 180 s 2.5 Dia 15m 7.7" 6b 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

1st Reset 159 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 1.1 0.8 1.1 2.8 5.9 2nd Reset 179.1 s 0.3 0.3 0.3 0.3 0.3 0.3 0.8 0.3 3.1 3.9

Controller: .25/2/3 FULL PAN: 40 s ST STATE: 150 s 2.5 Dia 15m n/a 1 8 21.3 30.5 36.6 42.7 48.8 54.9 61.0 64.0 67.1 70.1

1st Reset 171.5 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 2.5 11.3 11.3 11.3 NR

2nd Reset 195.7 s 0.3 0.3 0.3 0.3 0.3 1.2 4.8 4.8 NR NR

Controller: .25/4/4 FULL PAN: 40 s ST STATE: 150 s

a - No optical flame detector responses were recorded during test #1. NR - No response from detector. " - Estimated HRR used.
106 3 Warm Climate -15 m Facility

Table 27 shows the response times from ignition, along with pan size, heat release rate (HRR),

controller settings, time to full pan involvement from ignition, and time to steady state burning from

ignition.

During each experiment all of the UV/IR detectors were repeatedly reset at various times during the

test. The purpose of these resets was to obtain response time data at various stages of the fire (i.e.,

from ignition, full pan involvement from ignition, and steady state burning from ignition). Table 28

shows the response time corresponding to the first two manual resets after full pan involvement. Times

associated with each reset represent elapsed time from ignition. Table 28 also shows pan size, HRR,

controller settings, time to full pan involvement from ignition, and time to steady state burning from

ignition. In most cases the manual resets occurred after most or all detectors had responded, or changes

had stopped occurring. The average time between resets ranged from 10 s to 30 s. The minimum

response time from reset for any detector was 0.3 s, corresponding to the time it takes to actually reset the controller. The number of resets analyzed after achieving ftill pan involvement and steady state burning reflects the lowest common denominator (i.e., number of resets) for the vast majority of

experiments. In most cases, response time results for full pan and steady state conditions were taken

from the first two manual resets that occurred after these conditions were reached.

The response times from manual reset after steady state burning are listed in Table 29. Table 29 also

shows pan size, HRR, controller settings, time to full pan involvement from ignition, time to steady

state burning from ignition. As with the response times from full pan involvement, the response time

of each detector was determined from a manual reset occurring during the period of steady state burning.

Threshold Response Distances at Selected Response Times

Threshold response distances from ignition, full pan involvement and steady state burning were

examined at response times of 5 s, 10 s, 20 s, 30 s, and 45 s. Table 30 shows the threshold response

distances of the optical detectors for each fire size as a function of these selected response times. For

example, if the threshold response distance from ignition for the 2.8 MW fire in test 4 is shown as 30.5 m at 20 s, that means that 30.5 m was the maximum distance at which an optical detector

responded within 20 s for that fire test. These times were selected to indicate the maximum effective

response "distance" at which the detectors responded within a number of response time intervals.

Within DoD, the existing testing and approval criteria for optical flame detectors have been primarily

based on two sets of acceptance criteria. First, the Navy and Air Force design specifications require an

optical detector to respond to a 3 m x 3 m steady state JP-4 fire within 5 s. Factory Mutual requires an

optical detector to respond to a 1.5mx 1.5m steady state JP-4 fire within 10 s. Based on those

requirements, the actual voluntary tests standards which the industry has developed over the years

identify the following response distance thresholds shown in Table 3 1

.

Previous studies by the Factory Mutual Engineering Corporation indicate that the skin of aircraft

fuselages will fail after 45 s of spill fire exposure. [30] Unfortunately, those data do not represent the

decreased resistance to fire of today's typical composite material (i.e., stealth aircraft). Nevertheless,

45 s was the maximum response time used in determining threshold response distances. Further studies on the effect of fire exposure on aircraft skin will help determine acceptable response times of optical
3 Warm Climate -15 m Facility 107

Table 30. Threshold response distances (m) of optical detectors as a function of selected response

times for 15 m high facility tests

Test and Optical Detector Set-up laformation Distance (m) from Ignition at Selected Times

TEST NO. HRRfPAN SIZE) CONTROLLER 5s 10 s 20 s 30 s 45 s TESTl 0.1MW(.3mX.3m) .25/2/3 N/A^ N/A' N/A' N/A' N/A'

TEST II 0.1MW(.3mX.3m) .25/2/3 NR 12.2 12.2 15.2 15.2 TEST 2 O.SMW (.6 m X .6 m) .25/2/3 NR 21.3 25.9 36.6 36.6 TEST 12 N/A' MW (.6 m X .6 m) .25/2/3 12.2 12.2 15.2 2?.4 27.4 TEST 3 1.9MW(.9mx.9m) .25/2/3 NR NR 22.9 2?.4 39.6 TEST 4 2.8MW(1.5mdia) .25/2/3 NR NR 30.5 21.3 48.8 TESTS 6.8 MW (2.0 m dia) .25/2/3 NR NR 21.3 36.6 48.8 TEST? S.6 MW (2.0 m dia) .25/4/4 NR NR 21.3 36.6 48.

S

TEST 13" N/Ac MW (2.0 m dia) .25/4/4 N/A" N/A" N/A" N/A" N/A"

TEST 6B ?.? MW (2.5 m dia) .25/2/3 NR NR 30.5 36.6 67.1 TESTS N/A' (2.Smdia) .25/4/4 NR . NR 21.3 36.6 54.9

Test and Optical Detector Set-up Information Distance (m) from Full Pan Involvement at Selected Times

TEST NO. HRRfPAN STZE| CONTROLLER 5s 10 s 20 s 30 s 45 s TESTl 0.1MW(.3mX.3m) .25/2/3 N/A^ N/A^ N/A' N/A' N/A'

TEST 11 0.1MW(.3mX.3m) .25/2/3 15.2 15.2 15.2 15.2 15.2 TEST 2 O.SMW (.6 m x .6 m) .25/2/3 25.9 25.9 36.6 36.6 36.6 TEST 12 N/A' MW (.6 m X .6 m) .25/2/3 2?.

4

30.5 30.5 30.5 30.5 TESTS 1.9MW(.9mx.9m) .25/2/3 48.5 48.8 48.8 48.8 48.8 TEST 4 2.SMW(l.Smdia) .25/2/3 54.9 54.9 54.9 54.9 54.9 TESTS 6.S MW (2.0 m dia) .25/2/3 61 61 6?.l 6?.l 67.1 TEST? S.6 MW (2.0 m dia) .25/4/4 64 6?.l 6?.l 6?.l 67.1 TEST 13" N/A' MW (2.0 m dia) .25/4/4 42.? 48.8 48.8 48.8 48.8 TEST6B ?.? MW (2.S m dia) .25/2/3 64 ?0.1 ?0.1 70.1 70.1 TEST 8 N/A' (2.Smdia) .25/4/4 64 64 64 64 64

Test and Optical Detector Set-up Information Distance (m) f^om Steady State at Selected Times

TEST NO. HRRfPAN SIZE) CONTROLLER 5s 10 s 20 s 30 s 45 s TESTl 0.1MW(.3mX.3m) .25/2/3 N/A^ N/A' N/A' N/A' N/A'

TEST 11 0.1MW(.3mX.3m) .25/2/3 15.2 15.2 15.2 15.2 15.2 TEST 2 O.SMW (.6 m X .6 m) .25/2/3 25.9 36.6 36.6 36.6 36.6 TEST 12 N/A' MW (.6 m X .6 m) .25/2/3 30.5 30.5 30.5 30.5 30.5 TEST 3 1.9MW(.9mx.9m) .25/2/3 4S.8 48.8 48.S 48.8 48.8 TEST 4 2.8 MW (1.5 m dia) .25/2/3 54.9 54.9 64 64 64 TESTS 6.8 MW (2.0 m dia) .25/2/3 61 61 6?.l 67.1 67.1 TEST? 5.6 MW (2.0 m dia) .25/4/4 54.9 54.9 54.9 54.9 54.9 TEST 13" N/A' MW (2.0 m dia) .25/4/4 N/A" N/A" N/A" N/A" N/A"

TEST6B ?.? MW (2.S m dia) .25/2/3 6?.l 70.1 ?0.1 70.1 70.1 TESTS N/A" (2.5 m dia) .25/4/4 54.9 54.9 64 64 64

N/A' - no data recorded from test 1 . b - Open door test c - HRR data not available
108 3 Warm Climate- 15 m Facility

detectors. An additional element which must be considered in determining the acceptable response

time is the time required to achieve foam coverage of the designated floor areas after the fire has been

detected.

The controller settings of combination UV/IR detector were varied from test to test. Variations of

controller setting for similar sized fires was limited in these tests, with the result that the impact of

setting on threshold response distances at selected times was not conclusively determined. The effect of

the varied controller settings on threshold response distances at selected times are examined further in

section 4 dealing with the 22 m hangar fires.

Maximum Response Distances

The maximum response distances for the optical flame detectors in the 15 m facility were determined to be the maximum distance at which a detector responded without respect to the selected response times.

Since detector response was measured at three key fire events, the time at which the maximum

response distance was reached is represented for each stage of fire growth. The maximum response

distances are presented in Table 32 and graphically illustrated in Figure 47. The effects of different

controller sensitivity settings on the maximum response distance were studied for the 2.0 m and 2.5 m

diameter pan fires. The experiments with controller settings of 0.25/2/3 had a greater maximum

response distance than those with settings of 0.25/4/4 (Figure 48).

Predicted Response of Unitized UV/IR Optical Flame Detectors.

The researchers from Detector Electronics Corporation were asked to take the actual raw counts per

second data acquired from the each experiment and mathematically predict the responses of the unitized

optical flame detectors. This was done in order to compare them to the responses of the controller

based detectors. This analysis was performed for responses from ignition during a select time interval.

Table 33 lists the predicted response times for each detector placement. In addition, the unitized

maximum predicted response distances are shorter than the controller based detectors in nearly all cases. The predicted response times from ignition for the unitized detector were considerably longer in most cases.

3.4.6 Response of Line-Type Heat Detector

The line-type heat detector used in these test provided continuous measurement of temperature as a function of fire size. The specifications, theory of operation, and location can be found earlier in

section 3. The data from the sensor was compared to thermocouples NIO, S9 and W4 which

correspond to 3.0 m north, 3.0 m south and 9.1 m west respectively. The readings from these three

thermocouples were averaged to provide an estimate of temperature near the sensor. Figure 49 shows

temperature profiles of the thermocouples used and the resulting average, along with the response of

the linear heat detector for a 2.0 m diameter test fire. Figure 50 shows these comparisons for tests 1-5

(with draft curtain) and Figure 51 for tests 7,9,11-13 (without draft curtain). Results for tests 6b and 8

are not available due to a malfunction of the sensor's power supply during these tests.
3 Warm Climate -15 m Facility 109

Table 31. Voluntary industry standards which identify response distance thresholds for UV/IR

optical detectors

Fire Size Response Distance Threshold

0.3 m X 0.3 m (1 ft X 1 ft) 15.3 m (50 ft) 0.6 m X 0.6 m (2 ft X 2 ft) 30.5 m (100 ft) 3.0 m X 3.0 m (10 ft X 10ft) 45.7 m (150 ft)

Table 32. Optical detector response times at maximum distance from fire source for tests conducted in 15 m high facility

Test Information Controller

Setting

Threshold

Detector

Distance (m)

Maximum

Detector Placement (m)

Response Time (s) From:

Test No. HRR(Pan Size) Ignition Full-Pan Involvement

Steady

State TESTl 0.1MW(.3mX.3m) .25/2/3 N/A^ N/A^ N/A^ N/A^ N/A^

TEST 11 0.1MW(.3mX.3m) .25/2/3 15.2 48.8 25 1.9 1.9 TEST 2 0.5MW (.6 m X .6 m) .25/2/3 36.6 48.8 20.8 7.8 0.6 TEST 12 N/A^ MW (.6 m X .6 m) .25/2/3 27.4 48.8 28.6 0.8 0.3 TEST 3 1.9MW(.9mx.9m) .25/2/3 48.8 48.8 47 3.3 4.8 TEST 4 2.8MW(1.5mdia) .25/2/3 54.9 70.1 47.9 1.9 4.6 TESTS 6.8 MW (2.0 m dia) .25/2/3 67.1 70.1 61.6 0.3 3.3 TEST? 5.6MW(2.0mdia) .25/4/4 54.9 70.1 51.4 1.3 0.3 TEST 13 N/A-^ MW (2.0 m dia) .25/4/4 48.8 70.1 N/A^ 9.3 N/A"

TEST 6B 7.7 MW (2.5 m dia) .25/2/3 70.1 70.1 45.5 5.9 5.3 TEST 8 N/A-^ (2.5 m dia) .25/4/4 64 70.1 NR 11.3 4.8 NR - No detector response

a - No optical flame detector responses were recorded during test #1. Note: Test #13 is open door test. b - No valid data for optical flame detector responses from ignition and steady state were obtained from

Test #13.

c - HRR data not available
110 3 Warm Climate -15 m Facility

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(lu) e3ue;s|a

O

W)

B

o

I

o

o

03

'oO

o

o

to

t—

<u

03

*-> O

o

<L>

o

t

oU

00
112 3 Warm Climate -15 m Facility

Table 33. Predicted response times for unitized UV/IR optical detectors

Test #1

0.3 mx 0.3 m

0.1 MW

Loc^ition 9 fill l6.7m 12.2m 13,7m 15.2m 16.8ra' ISJm 2L3m 30.5m 48 8m

No Response Times were Recorded for Test 1

Test #11

0.3 mx 0.3 m

0.1 MW

Liiciilion .M-M.::. >MM.. : 18,3ni 2L;3rtl!;,::. .;.24,4m : .g7.4m:.^ .:|C>.5m,^ 36.6m ..:.:|?iM.::.. 4&.8m

0.25/2/3^ 9.1 25.0 NR NR NR NR NR NR NR NR

Unitize 3s NR NR NR NR NR NR NR NR NR NR

Unitize 0.5s 42.6 NR NR NR NR NR NR NR NR NR

Test #2

0.6 m X 0.6 m

0.5 MW

Lflcalion "l-f'lf-"' 'mw''^ "flfm"' 'Wm'' ''27;lm-- -p-;^si---- •iilm-:^-- 36 6m "'WiM 4$.«lm

0.25/2/3^ 5.5 10.4 10.4 11.7 21.5 18.8 20.8 20.8 67.2 NR

Unitize 3s 20.9 21.0 21.0 68.3 23.2 NR NR NR NR NR

Unitize 0.5s 11.9 15.6 18.5 20.7 20.7 66.5 NR NR NR NR

Test #12

0.6 m xO.6 m

[ 1

Location JlJffl 15.2111 18.3m 21.3m 24.4m 27.4m 30.5m 36.6m 42,7m ; :M-Mi

0.25/2/3" 1.5 16.1 25.6 28.6 28.5 28.6 NR NR NR NR

Unitize 3 s 30.8 30.9 50.7 54.2 NR NR NR NR NR NR

Unitize 0.5s 17.7 28.4 28.6 36.1 34.7 53.2 NR 52.0 NR NR

Test #3

0.9 m x0.9m

1.9 MW

:::.:.:;:y;^g^to,jj:jg: ^mms: mMM mmm. :mmiii: Mimli5!s5R?|: :::|m^,g :iiil:5 iSMm xiiiSiSSsi;

0.25/2/3" 18.5 18.2 29.2 22.7 21.5 30.8 35.5 33.0 44.5 47.0

Unitize 3s 34.1 34.7 34.9 35.2 34.7 47.9 NR NR NR NR

Unitize 0.5s 25.2 25.7 25.5 32.4 25.5 45.4 45.1 47.2 NR NR

Test #4

1.5 m Diam.

2.8 MW

Location 2L3m 30.5m 36.6m 42.7jS|; llllll ||4.9ra 61.0m 64.0m ilii llllll

0.25/2/3" 24.4 33.0 34.0 36.1 39.8 47.9 72.5 58.2 72.6 93.1

Unitize 3s 35.3 41.6 NR NR NR NR NR NR NR NR

Unitize 0.5s 26.6 35.7 39.8 48.0 NR NR NR NR NR NR

Tests

2.0 m Diam.

6.8 MW

Location

:

: 2:1,3m 30.5m 36,6m 42,7)Ti^ :48.8fn::;, ;:54.9ni :61.0m 64 Om 674m llllll

0.25/2/3" 17.3 23.6 24.8 30.6 33.6 45.2 43.4 41.7 61.6 69.9

Unitize 3s 25.9 40.8 41.5 60.3 93.2 NR NR NR NR NR

Unitize 0.5s 19.4 31.4 33.4 39.4 43.3 85.1 91.7 NR NR NR
3 Warm Climate -15 m Facility 113

Test #7

2.0 m Diam.

5.6 MW

% Location 2L3m 30.5m 36.6m 42.7ffl 48.8m 54,9m 6L0m 64.0m 67.iffl 70.1m/

.25/4/4^ 17.6 20.6 26.4 31.4 34.8 51.4 NR 61.4 NR NR

Unitize 3s 19.9 31.3 32.4 34.0 NR NR NR NR NR NR

Unitize 0.5s 17.4 20.6 29.9 31.5 37.9 53.3 NR 54.2 NR NR

Test #13

2.0 m Diam.

m^^^mmM MimMM^fiMMm^ iMim :::i§;ii*;: :<MMi<: M£mt:. 64.IDm MMmMMm

.25/4/4^ This Test Had No Valid Start Data

Unitize 3s 14.9 26.6 31.0 NR NR NR NR NR NR NR

Unitize 0.5s 10.2 18.7 18.7 28.7 28.7 61.0 61.3 NR NR NR

Test #6b

2.5 m Diam.

7.7 MW

W Location 213

m

30-.5 m

36,6'

m

42.7

m

48.8

ra

54.9

m

61,0

m

64.0

m

67.1

m

70.1-

m

.25/2/3'' 12.7 18.1 20.8 30.4 33.6 34.6 40.1 38.7 41.3 45.5

Unitize 3 s 23.0 38.8 40.3 46.6 NR NR NR NR NR NR

Unitize

0.5s

20.5 31.4 34.5 38.1 40.3 44.8 45.1 45.1 NR NR

Test #8

2.5 m

Diam.

Ig^^^^m^jmM ,21 3m xii^ig: 36 6m vMA<± MM:.: :MM.:< JMm,,> 64 am :J7,lm... MMi::

.25/4/4^ 13.3 23.6 28.7 35.7 37A 39.7 46.7 NR NR NR

Unitize 3s 23.0 31.5 38.6 47.8 56.3 NR NR NR NR NR

Unitize 0.5 s 14.6 23.4 29.4 35.8 37.3 39.8 55.0 NR NR NR

NR - No Response

a - Controller Based Detector Settings
114 3 Warm Climate -15 m Facility

Table 34. Test conditions and response parameters for the line type heat detector used in 15 m

high facility

Max. Center Max. Time to Time to Test Pan Size Fire Size

MW

Thermocouple Sensor 57 °C (135 79 °C

111 IVl w

+ 0.1

1 ciiipcidiuic

°C, + 2.0

XxCaUlll^ °C, + 3.0 s, + 4 s, +4

1 0.3x0.3 .1 30 30 a a

2 0.6x0.6 .5 43 41

3 0.9x0.9 1.9 56 53 a a

4 1.5 dia. 2.8 71 69 113 a

5 2.0 dia. 6.8 112 107 69 113

6b 2.5 dia. 7.7 150 n/a" n/a" n/a''

7 2.0 dia. 6.8 105 89 71 364

8 2 5 dia n/a'^ 157 n/a** n/a" n/a"

11 0.3x0.3 .1 34 31 a a

12 0.6x0 6 n/a' 44 36 a a

13'^ 2.0 dia. n/a^ 65 74 153 a

^ Did not reach temperature threshold specified. Not measured due to equipment malfunction.

"^ Heat release rate value not available. Open door test.
3 Warm Climate -15 m Facility 115

-120

TCNIO — -TCS9 — icysn

- - • TCA^age

120 240 aeo 480 eoo

nnB(s)

Figure 49. Temperature comparisons for thermocouples near linear heat detector for 2.0 m

diameter test fire (test 5).

Comparison ofLine-Type Heat Detector and Spot-Type Detector Response Times

Table 34 lists the fire sizes, maximum temperature at the center, maximum temperamre of the linear

heat sensor, and the time the sensor takes to reach 57 °C (135 °F) and 79 °C (175 °F). It is important

to know the time necessary to reach these temperature thresholds so that a comparison to spot-type heat

detectors and intermediate temperature range sprinklers can be made.

Table 34 shows that for the smaller fires that are less than 2 MW the sensor never surpassed the

threshold of 57 °C. This threshold corresponds to the alarm point of the spot-type heat detectors used.

However, in the tests with fires greater than 2 MW, the temperature exceeded 57 °C between 69 s and

153 s.

The first experiment where the temperature exceeded the 57 °C threshold was test 4. Spot-type heat

detectors at 3.0 m and 6.1 m east of center responded at 97 s and 184 s respectively. This is compared
116 3 Warm Climate -15 m Facility

to the linear heat sensor which reached the 57 °C level at 113 s. The heat detectors that were directly

above the sensor wire, at 3.0 m south and north, went into alarm at 197 s and 364 s. The linear heat sensor in test 5 reached the 57 °C threshold at 69 s. Spot-type heat detectors located within a 6. 1 m

radial distance from the center, alarmed at 71 s to 100 s. Without the draft curtain, the linear heat sensor reached the spot-type heat detector's alarm level in 89 s. Once again, the spot-type heat

detectors within the 6.1 m radius responded in a similar manner between 63 s and 138 s.

Comparison ofLine-Type Heat Detector and Sprinkler Response Times

The linear heat detector is also compared to the response of automatic sprinklers. In a typical

application, the linear heat detector may be used to activate a pre-action valve to supply water to the

sprinklers. It is important to know if the detector can trip the valve before any sprinklers are activated.

Table 34 indicates the time necessary to reach the activation temperature of the intermediate range

sprinklers used in these tests. In test 5, the linear heat sensor reached the 79 °C (175 °F) mark in

113 s. The first quick response sprinkler, located at the center, did not activate until 179 s.

In test 7 a 79 °C quick response sprinkler (C6) located above at the pan center activated at 312 s. The

linear heat sensor, located approximately 3.1 m out from the test centerline, did not reach the 79 °C

level until nearly 50 s later. These results for tests 5 and 7, comparing linear heat detector response to sprinkler activation, are represented graphically in Figure 52.

Ejfect ofDraft Curtains

The effect of the draft curtain can also be seen from the sensor data. For the smaller fires the effect is minor, but for fires greater than 2 MW the draft curtain contains and concentrates the heat. Figure 52

compares tests 5 and 7 and illustrates this point. It can be seen that with the same size fire, the linear

heat sensor in test 7 takes nearly 250 s longer to reach the 79 °C level than in test 5.
3 Warm Climate -15 m Facility 117

110 230

-| 1 1 1

1 r—T—T1

1

\ 1

1

1 1 1

1

1 r- 120 240 360 480 600 720

Alison 9090 Sensor Time (s)

Thermocouple Average (N10, S9, W4)

Figure 50. Line-type detector response for 15m facility tests with draft curtains.
118 3 Warm Climate -15 m Facility

110

100 -

90

20

Test?

Test 1

I

\

I

>

I

I

< < I

I

, , 1

^ r— 120 240 360 480

Alison 9090 Sensor Time (s) Thermocouple Average (N10, S9, W4)

600 720

230

220

210

200

190

180

170

160

<u 150

140

132

Q.

E

CD 1- 130

120

110

100

90

80

70

Figure 51. Line-type detector response for 15 m facility tests without draft curtains.
3 Warm Climate -15 m Facility 119

110

100

90

80

O^ 70

0)Q.

E 60

h50

40 -

30

20

Sprinkler Activation, test 5 @1 89 s Location: 3 m North, 175T QR

Tests

Alison 9090 Sensor Themnocouple Average (N10, S9, W4)

120 240 360 480

Time (s)

T 1

1

1 \ 1

1

1 1 1

1 T- 600 720

Figure 52. Line-type detector response for 2.0 m diameter pan fire (tests 5 & 7).

121

COLD CLIMATE EXPERIMENTS - 22 m fflGH FACILITY

The behavior of a fire plume and the response of detection devices in a cold building may not be

replicated well by the experiments held in the warm hangar in Hawaii. The Naval Air Station in Keflavik, Iceland, was chosen to conduct a second full-scale test program to check the significance of

ambient temperature on the performance of the fire protection systems. This second series also

permitted an evaluation of building geometry effects. Most significant are the increased ceiling height

(22 m vs. 15 mi) and ceiling shape (barrel-shaped vs. flat) in the Iceland hangar. The building

specifications, the installation of sprinkler heads and fire detection systems, the instruments used to monitor the fire behavior, and the results of 22 JP-5 and JP-8 pool fire expermients are presented in

this section.

4.1 Experimental Set-up

4.1.1 Building Specifications

The second series of fiill scale fire experiments were conducted in Hangar 83 1 at the Naval Air Station

in Keflavik, Iceland. This building was built in 1957 and consists of one large hangar maintenance bay

as well as adjoining industrial shops, offices and classrooms. A plan view of the hangar bay and fire area are shown in Figure 53. For the purpose of this section, all references to compass direction are made with respect to test north as shown in Figure 53

.

The hangar bay dimensions are approximately 73.8 m (242 ft) in length and 45.7 m (150 ft) in width.

The hangar roof is a curved (i.e., barrel-shaped) design with a ceiling height ranging from 12.2 m (40

ft) at the bottom of the arch to 22.3 m (73 ft) directly over the center of the hangar. A picture of the

roof assembly is shown in Figure 54. The primary roof support consists of a series of steel trusses which form arches spanning the width of the hangar bay, running parallel to the hangar doors. These

primary trusses are approximately 1.0 m (3.3 ft) deep and are spaced 7.4 m (24.3 ft) on center. The

primary trusses are interconnected with a series of secondary trusses which are perpendicular to them

and run the length of the hangar bay. The secondary trusses are spaced at intervals ranging from 5.8 m

to 6.4 m (19 ft to 21 ft) on center. The metal deck roof is directly attached to a series of steel beams

which sit on top of the primary and secondary trusses. These steel beams are perpendicular to the

primary trusses, are spaced 1.5 m to 2.1 m (5 ft to 7 ft) on center, and vary in height from 0.20 m to 0.30 m (8 in to 12 in).

The roof is insulated via a suspended tile ceiling which is supported by a conventional suspended tile ceiling grid located at the same elevation as the bottom of the steel beams (i.e., 0.20 m to 0.30 m

below the metal deck). The individual ceiling tiles in the center bay (test) and the adjacent bay (south) were removed prior to testing. Corrugated steel draft curtains subdivide the ceiling into five equal bays

approximately 14.8 m (48.6 ft) in width and 45.7 m (150 ft) in length. The draft curtains extend down

to approximately 13.4 m (44 ft) above the floor.

The east and west walls are a combination of concrete masonry units and gypsum board construction

with numerous unprotected window and door openings into the hangar bay. The north and south ends

of the hangar bay consist of metal and glass horizontal sliding hangar doors which are electrically
122 4 Cold Climate - 22 m Facility

operated. Figure 55 shows an elevation view of the hangar. Heat is furnished via geothermal hot

water unit heaters with electric fan units.

The hangar bay is fully protected by open-head deluge sprinklers on a pipe scheduled system with a protection area per head of 7.8 m^ (84 ft^) The sprinklers are supplied by seven independent deluge

valves which are activated by pneumatic heat actuated devices located at the ceiling. The existing

sprinklers and heat detectors were shut off during each of the fire tests.

4.1.2 Measurements - Fire Protection Devices

A number of conventional fire detection and suppression devices were installed and monitored to determine their actual response characteristics when subject to the experimental fires. The fire suppression devices were all standard spray upright sprinklers with a variety of temperature ratings,

actuation mechanisms, and response time indexes.

The fire detection devices consisted of photoelectric smoke detectors, fixed temperature heat detectors,

projected beam smoke detectors, combination ultraviolet/infrared optical flame detectors and line-type

heat detectors.

4.1.2.1 Sprinkler Installations

In the 22 m high facility, nine types of standard spray upright sprinklers with a variety of temperature

ratings, fusible elements, and response time indexes were installed and monitored to measure the

activation time of each sprinkler head when subject to a range of experimental fires. The sprinklers were configured in a similar manner to the 15 m high facility.

The fires were designed to determine the threshold fire size for response of each sprinkler type. Each

type of sprinkler head was selected because of its existing use or potential use in high bay applications.

NFPA 16A [2] and NFPA 409 [17] currently require that the temperature rating of sprinklers in

hangars be within the high (79 °C to 107 °C) or extra high (163 °C to 191 °C) temperamre range as defined by NFPA 13 [18]. Current Navy criteria requires the use of sprinklers with a temperature

rating of 141 °C [19]. Since ambient air temperatures at the ceiling level of aircraft hangars can

exceed 38 °C (100 °F), the lowest temperature sprinkler that could be reasonably installed in an

aircraft hangar is a 79 °C sprinkler which corresponds to the low end of the intermediate temperature

range. The nine types of sprinkler heads installed are shown in Table 35.

Figure 56 shows the location of each of the 15 sprinkler trees. Included in the figure are the

combinations of sprinkler types installed at each location. Each location contained a 141 °C quick

response bulb and 79 "C quick response bulb. The 141 °C head satisfies current Navy criteria and the

79 "C head would provide the first sprinkler response. In addition, the sprinkler stations within 6.1 m

of the plume also contained a 141 °C standard response bulb and a 141 °C standard response link to provide a point of comparison. Also, located within 3.1 m of the plume center, were a 141 °C quick

response bulb and a 79 °C quick response bulb in a dry-pipe configuration. The sprinkler station

located at the plume center contained a 79 °C standard bulb and a 182 °C standard bulb. The 182 °C

head was provided because NFPA 409 requires it for some hangars. All sprinkler heads and piping

assemblies used for the full scale tests were supplied by Viking Corporation. The sprinkler stations were again located at the ceiling above the center of the fire test area and spaced at 3. 1 m (10 ft)
4 Cold Climate - 22 m Facility 123

Table 35. Specifications for automatic sprinklers installed in 22 m high test facility

Activation

Temperature

, .°C

Activation Description Response Time Piping

Temperature Index (RTI)

m-s'''^

Configuration s °F

141 286 Quick Response Bulb 35 wet

79 175 Quick Response Bulb 35 wet

141 286 Standard Response Bulb 188 wet

141 286 Standard Response Link 95 wet

141 286 Quick Response Bulb 35 dry

'""""""79' """" ""^"175' """ Quick Response Bulb "'35 dry

93 200 Quick Response Bulb 35 wet

79 175 Standard Response Bulb 188 wet

182 360 Standard Response Bulb 188 wet

intervals in four perpendicular directions, to simulate the spacing between sprinklers in a typical hangar

installation. Since the roof was curved in the north and south directions relative to the hangar, the

piping was installed parallel to the curved portion to allow the sprinkler heads at each station to be a similar distance from the ceiling. Once again, a licensed sprinkler contractor installed the water mains

and riser nipples conforming to NFPA 13 specifications. The sprinkler main for the curved section of

the ceiling was fabricated using 3.1 m (10 ft) sections of Schedule 40, 38.1 mm (1.5 in) pipe coupled

with two 90° elbows and a tee. The 90° elbows would allow each section of the branch main to be

parallel with the curved roof. The east and west cross main were installed in a normal fashion. Valves

and fill/drain lines were installed on each end of the branch that ran in the north and south direction.

Filling and draining the branch and cross mains was performed from the floor of the hangar. Similar to the 15 m high facility, sprinklers were mounted at 0.20 m (8 in.) intervals on cross trees, with a valve

and union installed for purging air and filling the lines with water.

The sprinkler deflectors were installed between 0.30 m to 0.61m below the ceiling deck as indicated in Table 36. NFPA 13 also states that under obstructed construction, the sprinkler deflector shall be

located 0.25 m to 0. 15 m (1 in. to 6 in.) below the structural members and a maximum distance of 0.56

m (22 in.) below the ceiling/roof deck [18]. Ball valves were installed on each riser nipple to isolate

each sprinkler tree in order to prevent head pressure effects from sprinkler assemblies at higher

elevations, and to make the filling process more efficient. Each sprinkler tree included a vent port to relieve pressure, and purge trapped air from the line.

The time to activation for each sprinkler head was measured and recorded. The data collection rate for

the sprinkler activation time measurement was approximately 0.25 Hz. Provided the clip/wire

assembly activated freely, the time of activation was measured within 4 s to 8 s after actual activation.

Each sprinkler head was visually inspected between tests to determine if any activations occurred that were not recorded by the data acquisition system. All sprinkler heads that activated were replaced

between tests. Any sprinkler head that did not activate during the previous tests was inspected and
124 4 Cold Climate - 22 m Facility

Table 36 Automatic sprinkler deflector location and distance below ceiling as installed in 22 m

high test facility

Sprinkler Station Number

(as shown in Figure 56)

Location, Relative to Plume Center

Deflector Distance From Ceiling

m

C

Nl

N2

SI

S2

Wl

W2

W3

W4

W5

El

E2

E3

E4

E5

Center

3.0 m North

6.1 m North

3.0 m South

6.1 m South

3.0 m West

6.1 m West

9.1 m West

12.2 m West

15.2 m West

3.0 m East

6.1 m East

9.1 m East

12.2 m East

15.2 m East

0.61

0.36

0.43

0.38

0.30

0.56

0.46

0.56

0.56

0.56

0.61

0.61

0.61

0.46

0.61
4 Cold Climate - 22 m Facility 125

Doors

Test North

Computer and Equipment

22.9m

14.8m

i

Draft Curtain

14.8m

1

Draft Curtain

i4.8m 73.8m

Fire Test Area

i

Draft Curtain

14.8m

I

Draft Curtain

14.8m

Doors

K 45.7m M

Figure 53. Plan view of hangar bay, 22 m high faciUty.
126 4 Cold Climate - 22 m Facility

Figure 54. Photograph of ceiHng structure, 22 m high facihty.
4 Cold Climate - 22 m Facility 127

1.5 m- 2.1 m

Primary Truss (TYP)

5.8 m- 6.4 m

Secondary Truss (TYP)

T

12.2m

i_

Six-section hangar door

Figure 55. Detail of truss structure and elevation view of 22 m high facility.
128 4 Cold Climate - 22 m Facility

45.7

Branch main

0.6 m from

center truss E1 E2 E3 E4 E5

3.1 6.1 9.1 12.2 15.2 W5 W4

15.2 12.2

Center Truss

SI rt 3.1

S36 6.1

14.8

Draft Curtain

AB CD

ABC D E F

u. >

m. CO. m. Q

Q

A B C D o >

CD P p P A <l <l

< O

m<

D

m

n

lo. |a> IcD E FG

H 1

. B C DE F

A BCD

A- 14rC(286°F)QR Bulb B- 79°C(175°F)QR Bulb C 14rC {286°F)STD Bulb D 14rC (286T)STD Link E- 14rC (286°F)QR Bulb (dry) F- 79X (175°F)QR Bulb (dry) G 93°C (200°F)QR Bulb H 79°C (175°F)STD Bulb

1- 182°C (360T)STD Bulb

All Dimensions in Meters

Figure 56. Individual sprinkler locations within test area, 22 m high facility.
4 Cold Climate - 22 M Facility 129

cleaned prior to the next test fire.

All sprinkler heads and piping assemblies were supplied and installed by the Viking Corporation on

behalf of the automatic sprinkler industry. NIST was responsible for the data collection and the

installation of the wiring used to monitor the activation of the sprinkler heads. In cases where the

activation of a sprinkler head was not recorded by the data collection system, representatives from

Viking Corporation reported any activations to NIST.

4.1.2.2 Smoke and Heat Detector Installations

The instrumentation used in these experiments included photoelectric smoke detectors and two types of

electronic heat detectors. The photoelectric smoke detectors and analog addressable heat detectors were the same type of detectors used in the 15 m experiments. The rationale for their spacing and use,

as well as their wiring configuration and operating principles were defined in section 3.

The instrumentation for the 22 m high test facility included conventional hard-wired heat detectors

connected to the signaling line circuit through signaling line circuit interface devices. These detectors use a thermistor-type sensing element with an alarm threshold of 93.3 °C (200 °F). This detector type

employs a comparator circuit which compares the resistance in the thermistor to a reference resistor. When the difference between the thermistor and the reference resistor reaches a predetermined level,

the detector goes into alarm and sends an alarm signal to the fire alarm control panel [J03] . Data were

collected through the Simplex fire alarm control panel at a scan rate of 0.1 s.

There were 18 detector stations each consisting of a smoke detector, two heat detectors and one

signaling line interface device mounted to two plywood boards. The plywood boards were attached to the suspended acoustical tile ceiling grid which was the same approximate elevation as the sprinkler

deflectors. This distance ranged from 0.3 m (12 in) to 0.6 m (24 in) below the ceiling deck. The

acoustic ceiling tiles themselves were removed. The location of the detector stations with respect to the

fire plume center is shown in Figure 57. The detectors were only installed along the north/south and

east/west axes with respect to the center line of the fire plume. In addition, one detector station was

located outside of the north and south draft curtains at a distance of 9. 14 m (30 ft) from plume center.

Installation, calibration and test data from the smoke and heat detectors were provided by Simplex

Time Recorder Co., on behalf of the detector industry.

4.1.2.3 Projected Beam Smoke Detector Installations

The operating principle, sensitivity settings, and control feamres of the projected beam smoke detectors were described previously. Based on the beam detector performance in the 15 m high facility

experiments, the window settings for the beam detectors in the 22 m hangar were ail set at 5 seconds.

Sensitivity was either 20 % or 30 % as shown in Table 37. These settings remained constant for each

of the experiments.

Because the 22 m high facility has a domed ceiling whose slope exceeds 0.125, it is classified as a sloping-peaked typed ceiling as defined in NFPA 72. The concept for smoke detector placement and

spacing in buildings with sloped ceilings is derived from the location and spacing criteria developed for

heat detectors. NFPA 72 offers little guidance on the orientation of projected beam smoke detectors

other than the requirement that one detector be mounted within 0.9 m (3 ft) vertically of the peak, and
130 4 Cold Climate - 22 m Facility

H1

Hal

PI

9.1m

r

{

^

H7

\ J Ha7 ^^

P7

18.3m

H8

(

^^

Ha8

\ J P8 ^-^ 15.2m

Test North ^^^ ^^ H9 • (

^^

Ha9

\

^

P9 ^^ 12.2m

/^^ H10

( ) HalO

\^_y P10

9.1m - H11

(

^^

Hall

\

^

P11 ^^ 6.1m

H12

H2 H3 .—^ Ha12

Ha2 Ha3 / 1 P12

P2 P3 k^J 3.0m

6.1m /-—

3.0m

/-—

\

^—X /^~~\ o O^ource ( ) ( J

/''"^ H4 H5

H13 ) Ha4 Ha5

Ha13

P13

3.0m (10 ft) f

(

(

(

^-^ P4

3.0m

"~XH14

;Ha14

6.1m (20 ft) --"^HIS

JHalS ^—^ P15

9.1m (30 ft) ^^H16

;Ha16 ^^ P16

12.2m (40 ft) '^H17

^_^Ha17

P5

6.1m

H18 "-^P17

Ha 18 ^^^ 15.2m (50 ft)

18.3

P18

m (60ftK

/

^

H6

Ha6

P6

9.1m

Draft Curtain

Ha=Addressable Heat Detector

H = Heat Detector

P = Photoelectric Detector

All distances are from center (Source)

Figure 57. Plan view of smoke and heat detectors, 22 m high faciHty.
4 Cold Climate - 22 M Facility 131

that adjacent detectors be installed within their listed spacing. Due to obstructions in the ceiling created

by the steel trusses, a detector could not be located within 0.9 m of the top of the arch. Instead, this detector (i.e., T7/R7) was installed 1.3 m (4 ft) below the top of the arch. The remaining beam

detectors were installed with their beams running parallel to the draft curtains in order to achieve a

greater separation distance between the transmitters and receivers.

A total of seven projected beam smoke detectors were installed in the 22 m facility as shown in Figure

59. Detectors were installed at four elevations, 1.3 m (4.3 ft), 1.9 m (6.2 ft), 4.2 m (13.8 ft), and

10.9 m (35.8 ft) below the peak of the arched ceiling. One detector (T7/R7) was mounted at the 1.3 m

elevation with its beam aimed perpendicular to the draft curtains. The distance between this transmitter

and receiver was 13.6 m (44.6 ft).

Two detectors were mounted at each of the other three elevations with their beams aimed parallel to the

draft curtains. The distance between the transmitters and receivers were 18.8 m (61.7 ft) at the 1.9 m

elevation, 31.0 m (101.8 ft) at the 4.2 m elevation, and 45.8 m (150.3 ft) at the 10.9 m elevation.

These six detectors were each spaced 2.1 m from the edge of the draft curtain, and 10.6 m apart.

Installation, calibration, and test data were provided to NIST by Detection Systems Inc., on behalf of

the smoke detector industry. The detectors were hard-wired to the direct zones on the Simplex fire alarm control panel, and wired in the Class B, Style B configuration as defined by NFPA 72. In

addition, the auxiliary alarm contacts on each detector were also connected to the data acquisition

system which Detection Systems Inc. provided. Data were collected through the Simplex fire alarm

control panel at a scan rate of 0. 1 s.

•

4.1.2.4 Combination UY/IR Optical Flame Detectors

Ten controller-based combination ultraviolet/infrared (UV/IR) optical flame detectors were installed

and monitored during each experiment. A description of these detectors including general theory of

operation can be found in section 3. The ten UV/IR detectors were mounted on portable stands which

were located radially out from the fire. Each UV/IR detector was installed at a mounting height of 2.4

m (8 ft) above the floor. The detectors were placed to provide a direct line of sight to the fire. Distances from the detectors to the fire were measured along this line of sight as shown in Figure 59,

which is an example of the detector layout for the two larger detector fires and the sprinkler fires.

Detector locations varied with the fire pan size; however, for all 22 tests conducted there were

detectors placed at distances of 21.3 m, 30.5 m, and 45.7 m from the fire. The distance from the center of the pan to the furthest wall was 45.7 m. Locations for each detector for all 22 tests are shown in Table 38. All distances were measured along the floor from the detector to the center of the pan. For

the 0.3 m x 0.3 m square pan fires, additional detectors were placed at 1 .52 m intervals from 9.1 m to 18.3 m. For the 0.6 m x 0.6 m square pan fires, additional detectors were placed at 1.52 m intervals

from 22.9 m to 27.4 m, and at 3.05 m intervals from 33.5 m to 39.6 m. For the sprinkler fires (i.e.,

the 2.0 m and 2.5 m diameter pans and the 3.0 m x 3.0 m, 4.6 m x 4.6 m square pan fires), additional

detectors were placed at 1.52 m intervals from 24.4 m through 27.4 m and at 3.05 m intervals from

33.5 m to 42.7 m. The two sensitivity settings chosen for the experimental fires were 0.25 s gate

length, 2 counts per gate and 3 consecutive gates; and 0.25 s gate length, 4 counts per gate and 4

consecutive gates (Table 39). Each UV/IR detector was scanned at a rate of 10 Hz.
132 4 Cold Climate - 22 m Facility

Table 37. Sensitivity and window settings for projected beam smoke detectors installed in 22 m

high facility

Projected

Beam

Number

Receiver/Transmitter Pair Sensitivity'

% signal loss Window Settings*

s

Bl

B2

B3

B4

B5

B6

B7

Rl/Tl

R2/T2

R3/T3

R4/T4

R5/T5

R6/T6

R7/T7

20

20

30

30

30

30

20

Sensitivity and window settings remained the same for all experiments.
4 Cold Climate - 22 m Facility 133

DRAFT

CURTAIN

T5

13.6m

T6

i

0.6m E 2.1m

R3 T1

i

R1 T3 R5

Fire'Center

10.6m

R4

L^ 0"? Qm^^j

f -^ 9

15 5m ^

)

.4m

T2

1 R2 T4 R6

1 1

^^

2.1m

PLAN VIEW (a)

Test North

^

A

A

R = RECEIVER

T = TRANSMITTER

ELEVATION (b)

Figure 58. Plan and elevation views of projected beam detector locations, 22 m high facility.
134 4 Cold Climate - 22 m Facility

Table 38. Distances of UV\IR detectors (m) from fire center in 22 m high facihty

Pan Size (m) Detector Number

Detector Fires 1 2 3 4 5 6 7 8 9 10

45.7

45.7

0.3 xO.3

0.6x0.6

9.1

22.9

10.7

24.4

12.2

25.9

13.7

27.4

15.2

33.5

16.8

36.6

18.3

39.6

21.3

21.3

30.5

30.5

0.9x0.9,

1.2 X 1.2

42.7 24.4 25.9 27.4 33.5 36.6 39.6 21.3 30.5 45.7

Sprinkler Fires 1 2 3 4 5 6 7 8 9 10

2.0, 2.5 dia. 3.0x3.0,4.6x4.6

42.7 24.4 25.9 27.4 33.5 36.6 39.6 21.3 30.5 45.7
4 Cold Climate - 22 m Facility 135

Table 39. Controller settings for UV/IR detectors used in 22 m high facility

Test Number Description

(Pan Size)

Controller Settings

Gate Length (s) Counts per Gate Consecutive

Gates

1 0.3 mx 0.3 m 0.25 2 3

2 0.3 mx 0.3 m

0.6 mx0.6m

0.25

0.25

2

2

3

3

'"""""'''3"''"'^

4 0.6 m x 0.6 m 0.25 2 3

5 0.9 mx 0.9 m 0.25 2 3

6 0.9 mx 0.9 m 0.25

0.25

4

4

4

7 1.2mx 1.2m 4

8"

9

1.2mx 1.2m

0.3 mxO.3 m 0.25 4 4

10 0.6 m X 0.6 m 0.25 2 3

11 0.6 m X 0.6 m 0.25 2 3

12 0.9 mx 0.9 m 0.25 2 3

.,.....,...,...............,-:.,...,..,.13.,,,,,.,,,,.,...,.,,,.,,,.,,,. 1.2 mx 1.2m 0.25 4 4

14 2.5 m Diameter 0.25 4 4

15 3.0 m x3.0m 0.25 4 4

16 2.5 m Diameter 0.25 4 4

17 3.0 m x3.0m 0.25 4 4

18 2.0 m Diameter 0.25 4 4

19 2.5 m Diameter 0.25 4 4

20 3.0 mx 3.0 m 0.25 4 4

21 4.6 m X 4.6 m 0.25 4 4

22 4.6 m X 4.6 m 0.25 4 4

" UV/IR data was not collected for test 8.
136 4 Cold Climate - 22 m Facility

Test and Fire Pan Center Point

© UV/ IR Detector

Figure 59. UV/IR detector locations within test area, 22 m high facility.
4 Cold Climate - 22 m Facility 137

4.1.2.5 Line-Type Heat Detector Installation

A line type heat detector provided by Alison Control Inc. was used to monitor the perimeter of the

draft curtain area in the 22 m high facility. The Alison 9090-13 as described in section 3 was used.

Based on the fact that NFPA 72 does not specify placement of line type electrical conductivity detectors

in spaces greater than 9.1 m (30 ft) high [20], consultations with the manufacturer were necessary to determine proper placement. The Alison 9090-13 linear heat detector, as shown in Figure 60 was

located within the test area 0.3 m (1 ft) from the north and south draft curtains, along the center truss, and approximately 4.3 m (14 ft) from the east and west walls of the hangar bay. The sensor consisted

often 15.2 m (50 ft) sections connected using in-line, sealed connectors. The sensor was hung

approximately 0.3 m below the structural steel beams. Special beam mounted hangers were provided

by the manufacturer to support the sensor.

Using the customized control box supplied by the manufacturer, an analog voltage output was recorded

of the temperature of the sensor at any given moment.

4.1.3 Measurements - Instrumentation

NIST installed and monitored 144 transducers during these fire tests. Sixty four measurements were of

sprinkler activation time, as described in section 3. Other transducers and instrumentation included

North Draft Curtain

0.3 m (1 ft.)

Terminal Box

Source -^

Center Hangar Bay (Test Area)

14.8 m

(48.6 ft.)

A- 45.7 m (150 ft.)

South Draft Curtain

Figure 60. Linear heat detector location diagram, 22 m high facility.
138 4 Cold Climate - 22 M Facility

thermocouples, mass loss of burning fuel, mass flow of the ceiling jet structure, internal and external

wind speed and direction, and heat flux radiometers. In addition, video recordings were made at several locations for visualization and analysis purposes.

Temperatures

Sixty four thermocouples were installed in the 22 m facility in order to measure hot gas, air and fuel temperatures. Figure 63 shows the thermocouple layout. Type K thermocouples were used to measure

these temperatures. Temperature measurements for the 22 m high facility varied somewhat from that of the 15 m high facility described in section 3. The measurements differed in that temperature was

measured for the first series of experiments (shown in lower dotted box in Figure 61) and ceiling jet

profile temperatures were measured for the repeat tests. All other locations were measured for all tests. These configurations allowed NIST to collect more complete information about these phenomena.

Described below are the general locations of thermocouples and rationale for their placement.

To measure plume centerline temperatures, thirteen temperature measurements were taken over the

fire plume. An array of five thermocouples was placed at 0.31 m below the ceiling, one in the center over the fire pan, and one 3.0 m radially out from the center in each of the four directions. Along the

centerline, four thermocouples were installed at 1.5 m, 3.0 m, 4.6 m, and 6.1 m below the ceiling.

Similar measurements were made at 3.0 m in the east direction at the same elevation as the centerline

thermocouples. These provided some measure of direction the plume was leaning.

To measure the ceiling jet temperature, thermocouples were placed along the curved portion of the

ceiling in the east direction at 9.1 m, 12.2 m, and 15.2 m (shown in upper dotted box in Figure 61).

At these locations thermocouples were placed vertically down from the ceiling to measure the

temperature of the ceiling jet as a function of depth below the ceiling. Thermocouples were placed at 0.15 m, 0.46 m, 0.61 m, 0.76 m, and 0.91 m below the ceiling. This information is useful for fire model verification, detector placement strategies, and comparison to data collected in 15 m high

facility.

To track heat and smoke fllling the draft curtained area, thermocouples were placed along the

curved portion of the ceiling in the east direction at 3.0 m, 6. 1 m, 9. 1 m, and 12.2 m from the

centerline. Assuming that the smoke and heat flow together, the thermocouple readings can indicate the

initial arrival of smoke to the thermocouple location. Also, in the south direction, along the flat portion

of the ceiling, temperatures were measured at3.0m,4.6m,6.1m, and 6.7 m (shown in lower dotted

box in Figure 61). The distance below the ceiling deck for these smoke filling measurements was based on elevation of the thermocouples along the centerline. The goal was to establish a plane of

temperature measurements in two directions, at different distances form the ceiling. Thermocouples were installed from 0.30 m to 6.1 m below the ceiling (at centerline). The distance to the "temperature

planes" from the hangar floor (used as a flat reference) were approximately 22.0 m, 20,8 m, 19.3 m,

17.7 m, and 16.2 m. Also, prior computer simulations had suggested that the deep draft curtains used

in this facility would cause a circulation pattern to form in the draft curtained area instead of a uniform

smoke layer slowly filling the volume.

To track the flow of heat and smoke into the adjacent draft curtained areas, thermocouples were

installed outside of the draft curtained area in the south direction. Thermocouples were placed in the

adjacent bay at 7.9 m, 12.2 m, and 21.6 m from the centerline and 0.3 m and 6.1 m below the ceiling.
4 Cold Climate - 22 M Facility 139

As before, computer simulations suggest that the hot gases within the adjacent bay would tend to progress along the ceiling and down the far curtain. The measurements in the adjacent bay would

therefore be used to compare actual results with those provided through the computer simulations.

To measure the temperature at time of activation of smolce and heat detectors, a thermocouple was

placed at each sprinkler tree/smoke detector station. These data provide information useful in model

verification and prediction of activation of fire protection devices.

To provide critical safety temperatures, a thermocouple was placed on the main structural steel beam

directly over the fire. Two thermocouples were placed within the fire pan to monitor fuel depth and

pan temperature.

Mass Loss of Burning Fuel

Measurement of the mass loss rate of the burning fuel was essential for determining approximate heat

release values for each test fire. This measurement also provided information on the time required for

the fire to reach steady state burning. Heat release rates were estimated for nearly all test fires provided mass loss data were available. Using the mass loss rate (kg/s) muhiplied by the known heat

of combustion, H^, for each fuel (kJ/kg) results in heat release rate (kW).

Since a load measuring platform had to accommodate small and large pan sizes, it was necessary to build two load platforms for this test series. Figures 62 and 64 describe the load platforms. The

smaller three-point load platform used three 227 kg (500 lb) strain gauge type precision load cells,

provided by GSE Inc. Measurements and Controls. Coupled with a strain gauge power supply/

indicator, a voltage output of Vdc to 5 Vdc, directly proportional to total mass (kg) was recorded.

For the larger four-point load platform, four 454 kg (1000 lb) strain gauges were used. This

configuration provided a total mass capacity of 1814 kg (4000 lb).

Calibrations were performed on the strain gauges prior to fire testing. The three 227 kg gauges were

anchored to a small cylindrical plate and subjected to a vertical load. Using a hydraulic load testing

machine at NIST, approximately ten points from kg to 227 kg were recorded, along with the

corresponding voltage output. The four 454 kg (1000 lb) gauges used on the larger load platform were

anchored to a small square plate and similarly calibrated. On-site load calibrations were made using

18.1 kg (40 lb) water containers placed on the load platform. These containers were filled with water

and weighed independently using a calibrated lab balance. The weight of each container when filled was 18.5 + 0.23 kg (40.7+0.5 lb). Each strain gauge and associated wiring was thermally protected

using a ceramic blanket wrapped loosely around the gauge and the load platform frame was protected

using 12.7 mm (0.5 in.) calcium silicate board.

Ceiling Jet Velocity Transducers

Ceiling jet velocity measurements were made using two Sierra Steel-Trak Industrial Insertion Mass

Flow Meters (series 640). Detailed information on the operating principles of this transducer is given

in section 3. Locations of these mass flow meters are shown in Figure 61. V, in the figure is located

6.1 ni (20 ft) in the east direction and is positioned at nearly the same elevation (0.3 m below ceiling

deck) as the thermal element of the sprinkler at station E2. Vj is located at 12.2 m (40 ft) in the east direction and also 0.3 m below the ceiling deck in the vicinity of sprinkler station E4.
140 4 Cold Climate - 22 m Facility

E4Ja3 : E4Jb3 ; E5JaJ E4JC3

E5Jb! t E4jdj ;

E5Je; t

E3Jalt 0.15 ESJbi: 0.46 E3JC3

0.61 E3Jd1 : 0.76 E3JeJ 0.91

E7a 3.0

Side Wall

WEST

Sprinkler w/TC

TConly X22.9

Mass Flow Meter (0.31 m below ceiling) Radiometer

R, (1.2 m off floor) R2 (6.1 m below ceiling) R3 (0.31 m below ceiling)

All Dimensions in Meters

21.6

22.3 S7

-•I

12.2 S6

-»i

7.9 6.7 S5 7.3 S4

-IKSOUTH

6.1 4.6 3.0 S3 S2 S1 a M fl

NORTH

3.0 N1

6.1 N2

*S7d *S6d S5d*

Adjacent Bay

tS4a nS3a;tS2a US1a-1.5

S4b

{S4c

US4d

S3b tS2b

S3c *S2c *S

!;S3d icS2d |tS1d-6.1

tS1b-3.0

1c -4.6

Draft Curtain

Figure 61. Instrumentation locations in 22 m high facility.
4 Cold Climate - 22 m Facility 141

50.8 X 50.8 mm Aluminum Tube

Welded Supports

12.7 mm x .38 m dia. Aluminum Plate

12.7 mm x 0.203 m dia. Aluminum Plate

Welded Supports

Model 5353 227 kg

(500 lb.) Strain Gauge

12.7 mm Calcium Silicate Board

Figure 62. Three-point load platform used to measure mass loss in 22 m high facility experimental

fires.
142 4 Cold Climate - 22 m Facility

Aluminum Plate n

Square Rod

Welded to Plate

Load Cell Assembly Bottom Plate

Partial Detail

4.57 m (15 ft.)

Aluminum Plate protected

with Calcium Silicate Insulation Board

Figure 63. Four-point load platform used to measure mass loss of larger pan fires conducted in

22 m high facility.
4 Cold Climate - 22 M Facility 143

An output voltage signal Vdc to 5 Vdc is produced which is proportional to the total mass flow. The

usable range for these transducers is standard m/s to 0.5 standard m/s (0 ft/min to 100 ft/min).

Wind Speed and Direction Meters

Wind speed and direction were measured inside and outside the hangar during the experiments. Four

wind speed/direction meters were used in the following manner. One meter was mounted on the roof

at the south end of the hangar to observe ambient wind conditions. The other three meters were placed

within the hangar at various locations depending on the fire test size. Figure 66 describes the location

of each sensor. The four wind speed/direction sensors were calibrated at NIST in a standard wind

tunnel. Additional information and theory of operation on these sensors can be found in section 3.

Heat Flux Meters

Three water cooled, Gardon type heat flux transducers were used to measure total heat flux from the

test fires. Figure 61 indicates the location of the gauges. Two transducers, R2 and R3 were mounted at 12.2 m from the test center in the east direction. Depending on the fire pan size, Rl was positioned at various distances away from the pan. Transducer R3 was mounted 0.3 m below the ceiling and

transducer R2 was mounted 6.1 m below the ceiling. The third transducer, Rl, was positioned 1.63 m

off the floor for the first 4 tests, and at 1 .07 m for rest of the test series. Cooling water for these

transducers was provided by the water supply used for filling the sprinkler trees. Plastic hose (9.5 mm

O.D.) was used to supply the transducers and provided a drain line which was piped to a central drain

in the hangar. Section 3 describes the operating principle of these transducers.

Data Acquisition System

The data acquisition system used to collect fire test data in the 22 m high facility was the same system

used in the previous test series. Additional information and a block diagram of the system can be

found in section 3. The overall system scan rate for all 144 channels varied between 3.5 s and 4.5 s depending on the graphical display requirement for each test.

Other Measurements and Information

In addition to measurements described above, video footage of each test fire was taken. In all cases, high resolution 8 mm cameras were located in two specific areas with respect to the test fire. Camera 1 was approximately 14.3 m (47 ft) from the center of the test fire, looking in the direction of the east wall of the hangar. Height markings were placed on the east wall at equal intervals, to provide a visual

flame height measurement. Camera 2 was located in the northeast corner of the test area to provide

footage of smoke filling rates and relative obscuration. Camera 3 was portable so as to capture

important events during the tests. The locations of cameras 1 and 2 complimented one another by also

supplying information on time to full pan involvement, flame propagation across fuel pan, flame

structure, and symmetry of the plume.

Weather data, measured at several locations near the hangar, were provided by the weather station at NAS Keflavik. Temperature, relative humidity, wind speed/direction, dew point, barometric pressure,

and precipitation amounts were all reported hourly. In addition, relative humidity was measured inside

the hangar prior to each test.
144 4 Cold Climate - 22 M Facility

4.2 Test Fires in 22 m High Facility

Twenty-two fire experiments were conducted in the 22 m high faciUty. The majority of these fires involved JP-5, and the remainder burned JP-8. The jet fuel fires ranged in size from 0.06 m^ (1 ft^) to 20.9 m^ (225 ft'). The following sections include the rationale for each fire size, computer modeling of

the facility based on anticipated heat sources, test procedures, summary of all experiments, and fuel specifications for JP-5 and JP-8.

4.2.1 Rationale for Experimental Fire Sizes

A combination of plume theory, three-dimensional computational fluid dynamics modeling, and

engineering judgement were used to determine the heat release rates and associated pan sizes to meet

the experimental objectives. Each of the experiments can be grouped into one of two categories, one

referred to as "detector fires" and the other "sprinkler fires." Detector fires were designed to determine the approximate minimum fire size for detectability for the various types of heat, smoke, and

flame detectors installed. Detector fires were small square pan fires of four different sizes: 0.3 m x 0.3

m (1 ft X 1 ft), 0.6 m X 0.6 m (2 ft X 2 ft), 0.9 m x 0.9 m (3 ft x 3 ft), and 1.2 m x 1.2 m ( 4 ft x 4 ft). The detector fire sizes were chosen to correlate with those conducted in the 15 m high facility in order

to determine the effect of the higher ceiling on the maximum ceiling temperature and the response of

the various detectors. The larger 1.2 m x 1.2 m detector fire was added due to the higher ceiling

height.

The sprinkler fires were a combination of round pan fires and large square pan fires. Sprinkler fires were designed to determine the approximate fire size for activation of the various types of automatic

sprinklers. An ambient temperature of 7 °C (45 °F) was assumed for calculation purposes. Sprinkler

fires were designed to meet four objectives:

• To demonstrate a large fire that would come close to but not activate any of the installed test sprinklers. The first sprinkler fire was a 2.0 m diameter circular pan fire with an estimated

heat release rate of approximately 8 MW.

• To demonstrate a fire large enough to activate the 79 °C (175 °F) sprinklers within the fire plume. The second sprinkler fire was a 2.5 m diameter pan fire with an estimated heat release

rate of approximately 13 MW.

• To demonstrate a fire that would activate the 79 °C (175 °F) sprinklers inside and outside the

fire plume and the 141 °C (286 °F) within the fire plume. The third sprinkler test was a 3.0 m

X 3.0 m (10 ft X 10 ft) square pan fire with an estimated heat release rate of 20 MW.

• To demonstrate a fire that would activate the 141 °C (286 °F) sprinklers inside and outside the

fire plume. The fourth sprinkler test was a4.6mx4.6m(15 ftx 15 ft) square pan fire and

with an estimated heat release rate of 45 MW.

The fire experiments were conducted in the center draft curtained area, which measures 14.8 m

(48.5 ft) in width by 45.7 m (150 ft) in length. Some of the key fires were repeated with JP-8.

Laboratory scale experiments discussed in section 2 showed similar heat release rates for JP-5 and

JP-8.
4 Cold Climate - 22 M Facility 145

4.2.2 Computer Modeling of 22 m Facility

Computer modeling for the 22 m high faciUty was focused toward predicting the impact that the curved

ceiling and large draft curtains would have on smoke and heat flow. The draft curtains had depths of

8.7 m (28.5 ft) which should substantially inhibit the flow of heat outside of the curtained area. Predictions were also made concerning the fire size required to activate a 141 °C (286 °F) sprinkler

heads at the ceiling. Finally, the effect that wind blowing in the open side of the hangar would have on

the fire and heat flow was investigated.

The CFD model, HARWELL FLOWSD was used to investigate the hot gas flow since this hangar had

a curved roof and the available zone models only allowed for flat roof simations. Initially, the hangar was modeled without draft curtains in order to separate the draft curtain effects on the hot gas flow

from that of the curved roof. The results of these calculations revealed that the flow of heat in the

direction of the curved ceiling would be slowed by the curved ceiling. Including the draft curtains into

the calculation provided a major change in the hot gas flow patterns. The draft curtains were deep

enough to completely contain the heat early in the fire. Figure 65 shows the temperature patterns

within the draft curtains for a 32 MW fire at 60 s into the simulated fire. The flow moves along the

ceiling, down the draft curtain, and turns back toward the fire plume. As the hot gas flows beneath the

draft curtain, it flows up the other side and is trapped by the adjacent draft curtain as shown in Figure

65. Inside the second draft curtained volume, filling of the far side should occur prior to filling the

side adjacent to the first draft curtain. Based on these calculations, two sets of thermocouples were

designed to investigate these flow patterns.

To investigate ceiling temperatures versus fire size, calculations using 32 and 40 MW fires at an

ambient temperature of 7 °C (45 °F) predicted maximum ceiling temperatures at plume center of

201 °C (394 °F) and 243 °C (469 °F) 60 s into the simulated fire. The simulated fire was designed to reach its maximum heat release rate during the first 10 s. Both fire sizes were predicted to activate all the 141 °C (286 °F) sprinkler heads enclosed by the draft curtains in the direction perpendicular to the

curved ceiling. In the direction parallel of the curved ceiling, activation of all 141 °C heads should occur 15 m (49 ft) from plume center for the 32 MW fire and all the way to the wall for the 40 MW

fire. Either fire size should meet the goal to activate the high temperature sprinkler heads both inside

and out of the plume region regardless of the range of ambient temperatures expected for these

experiments.

The effect of wind blowing in one hangar door was investigated for a 32 MW fire. It was assumed that the hangar door was fully opened and that there was a small leak at the bottom wall on the hangar side

opposite the door. The wind was assumed to be blowing perpendicular to the door and have a constant

vertical velocity profile. Figures 66 and 67 show the results of the calculations for flow velocity and

local gas temperatures with a wind speed of 8.9 m/s (20 mph). Figures 68 and 69 show the results of

the calculations for flow velocity and local gas temperatures with a wind speed of 17.8 m/s (40 mph).

In both cases, the wind is deflected down by the door opening and by the time it reaches the center of

the hangar, the strongest velocity component is near the floor. The 8.9 m/s wind will produce some

flame lean and show preferential smoke filling of the draft curtain area centered under the fire and die one immediately behind the fire opposite the open door. As the wind speed increases to 17.8 m/s, the

fire should exhibit a significant flame lean with insignificant amounts of smoke filling draft curtain areas on the door side of the flame. The available venting area in the side of the hangar opposite the

open door should have a significant impact on the amount of flame lean and hot gas flow.
146 4 Cold Climate - 22 m Facility

Iceland Hangar

32 M^V Fire, 60 s

Temperature, Deg C

> 1 77

1 7 7

1 3 7

9 7

5 7

1 7

1 7

Figure 65. Side view of the 22 m high facihty in a plane through the fire center. The draft curtains are represented by two vertical lines extending from the ceiling to just below

the side roof level. The 32 MW fire is located on the hangar floor at the right side of

the figure.
4 Cold Climate - 22 M Facility 147

If the hangar is more open on the opposite side than is assumed in these calculations, the slow down of

the wind velocity will lessen and the wind impact on the fire and plume will be enhanced.

Two different thermocouple configurations were used for test fires in the 22 m hangar. The goals of

the first configuration were to measure the ceiling jet flow along the curved portion (i.e., east - west) of

the hangar roof, to measure the temperamre at the smoke detectors and sprinkler heads, and to measure the rate of smoke filling in the hangar. Computer simulations had indicated that the rate of hot

gas flow along the curved roof of the hangar would be slowed compared to the rate of hot gas flow in the direction of constant ceiling height (i.e., north - south). In order to test this prediction and also measure the overall hot gas filling rate of the hangar, thermocouples were located 0.15 m ( 6 in.)

beneath the ceiling at fire center and at 3.0 m, 6.1 m, 9.1 m, 12.2 m, 15.2 m, and 23 m (0 ft, 10 ft, 20 ft, 30 ft, 40 ft, 50 ft, 60 ft, and 75 ft) along the curved ceiling in both the east and west directions

from the fire center. In addition, a thermocouple was mounted at 23 m (75 ft.) from fire center and 6.1

m beneath the ceiling in the east direction. In addition, thermocouples were located 0.15 m beneath the

ceiling at 3.0 m, 4.6 m, 6. 1 m, and 6.7 m in the south direction and at 3.0 m and 6. 1 m in the north

direction. This set of thermocouples would be used to measure the time of arrival of the hot gases at each location.

A set of thermocouple trees was designed to measure the vertical temperature profile of the ceiling jet

along the curved section of the ceiling. Here, thermocouple trees located at distances of 0. 15 m, 0.30

m, 0.46 m, 0.76 m, and 0.91 m below the ceiling at 9.1 m, 12.2 m and 15.2 m distances along the

curved ceiling toward the east direction. The thermocouples would be used to measure the temperamre

profile of the ceiling jet at three locations outside the plume. The vertical spacing of the thermocouples

in these trees were increased over the distances monitored for the 15 m high facility based on the

results obtained from the 15 m high bay facility experiments and the larger fires designed for these

experiments.

The second thermocouple configuration was designed to examine the hot gas movement within the draft

curtained area as a function of depth beneath the ceiling. Computer simulations had suggested that the

deep draft curtains used in this facility would cause a circulation pattern to be set up in the draft curtained area instead of a uniform hot gas layer slowly filling the curtained volume. Secondly,

computer simulations suggested that these draft curtains would be deep enough to contain the hot gases

for some time with hot gas flow into the adjacent curtained regions occurring later in the fire. When

hot gas flow did spill into the adjacent curtained areas, it would tend to drop down the side of the

curtain, move along the ceiling and then back down the far curtain, leaving the middle of the curtained

area void of hot gas for an additional period of time.

In order to test these predictions, the thermocouples used to measure the vertical temperamre profile of

the ceiling jet were replaced by four thermocouple trees in the south direction with thermocouples at depths beneath the ceiling of 0.15 m, 1.5 m, 3.0 m, 4.6 m, and 6.1 m and distances from the plume

center of 3.0 m, 4.6 m, 6.1 m, and 6.7 m. In addition, four thermocouple trees in the east direction were replaced with thermocouples at depths beneath the ceiling peak of 0.15 m, 1.5 m, 3.0 m, 4.6 m,

and 6.1 m. Utilizing a second tree at plume center with the same thermocouple configuration, two

measurement planes were used to track the time needed for the hot gases to fill the draft curtain

volume. In the adjacent draft curtain to the south, three thermocouple trees were located at distances of

7.9 m, 12.2 m, and 22.6 m from the fire center. Each tree had thermocouples located at depths of

0. 15 m and 6. 1 m from the ceiling.
148 4 Cold Climate - 22 m Facility

Iceland Hangar

32 MW Fire, 8.9 m/s Wind

Long Arro\vs Represent 8.9 m/s Wind Speed

Figure 66. Side view of 22 m high facility in plane through the fire center. Rectangle at far right

represents region outside of hangar with door and wall represented by vertical lines on

side of rectangle. Draft curtains are represented by vertical lines extending from

ceiling to just below pair of horizontal lines near middle of figure. Arrows: direction

and magnitude of velocity. 32 MW fire located on hangar floor centered between

second and third draft curtains from hangar door. Wind speed 8.9 m/s (20 mph).
4 Cold Climate - 22 m Facility 149

Iceland Hangar

32 MW Fire, 8.9 m/s Wind

Temperature Deg.

127.0

127.0

99.5

72.0

42.5

17.0

Figure 67. Contours represent local gas temperatures from the 32 MW fire and with a wind speed

of 8. 9 m/s.
150 4 Cold Climate - 22 m Facility

Iceland Hangar

32 MW Fire, 17.8 m/s Wind

Long Arro^vs Represent 17.8 m/s Wind Speed

\ \ \ \ I

\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ A , TTTT

X \ \ \ A A \ \ 1 , , \ \ \ \ \ X A \ \ , , N \ \\\\\\\N.

N \ \ \Naa,\\\v.

V V \ \ \ N.\.\\N-

^ V V \ \ \

-. ^ K S \ \'

Figure 68. Similar modeling configuration of 22 m facility as described in Figure 66. Wind speed

is 17.8 m/s (40 mph).
4 Cold Climate - 22 m Facility 151

Iceland Hangar

32 MW Fire, 17.8 m/s \Vind

Temperature Deg

I>

127.0

127.0

" 7 2.0

44 . 5

< 17.0

Figure 69. Similar modeling configuration of 22 m facility as described in Figure 67. Contours

represent local gas temperatures from 32 MW fire, wind speed of 17.8 m/s.
152 4 Cold Climate - 22 M Facility

The two sets of four thermocouple trees in the east and south directions plus the center thermocouple

tree formed planes which allowed the hot gas filling within the draft curtains to be monitored. The

three thermocouple trees in the adjacent draft curtain will be used to analyze the time to spill over and

the flow pattern with this draft curtained volume.

4.2.3 Experimental Procedures and Test Information

A test procedure was developed to ease the many tasks required to conduct each full scale experiment.

These tasks were supervised by the project leader according to the following procedures.

Equipment Check

Instrumentation and fire protection devices were inspected before each experiment. Thermocouple and

sprinkler connections were electronically checked to ensure no open circuits. Initially, thermocouples were tested with a small heat source to ensure temperature response and switch-like sprinkler

connections were inspected to verify operation. Each data channel was checked for proper

measurement and response. Channels or measurement points with incorrect or intermittent operations were repaired. The data system was readied for the upcoming experiment. Power supplies and

controllers for wind speed transducers, linear heat sensor, load platform, and mass flow transducers were examined for proper operation. Water supplies for the three water-cooled radiometers were

inspected for proper flow. Video cameras used to capture test footage were positioned. The camera

designed to aid in flame height measurements was placed at a known distance from the fuel pan with a backdrop of elevation markings at 1.5 m (5 ft) intervals starting at the floor.

Projected beam detectors were inspected for proper alignment and operation. A nominal output voltage

of four volts from each detector confirmed operation. A lower output meant the detector's lens was

dirty or the unit was defective. Lenses were manually cleaned after nearly all experiments. Smoke and

heat detectors were inspected to confirm acceptable operation and the central fire alarm panel provided

a measure of percent-of-alarm for each detector. Generally, a value greater than 1 % to 2 % suggested

that the detector needed to be cleaned or replaced. To speed these changes, detectors were installed

onto mounting plates so they could be easily removed. Upon completion of the larger fire tests, most

detectors were replaced. UV/IR detectors were located at pre-determined distances from the fire pan.

A small hand held source, used as a calibration, was directed at each detector and necessary

adjustments were made. The temperature of the water contained in the sprinkler piping was measured.

If the temperature of the water was higher than ambient, the water was drained and the piping refilled.

Set Fuel Pan

The next major step in the procedure was to position the load platform and appropriate fuel pan. It was

critical that these elements were centered so that measurements concerning plume symmetry,

temperature and hot gas movement could be referenced to a central consistent location. The pan was

then leveled on the load platform and the weight of the empty pan was measured using the load cell controller. An LED indicator on the controller provided a continuous display of the weight in appropriate engineering units. Depending on the pan size (i.e., 2.5 m diameter and 3.0 m x 3.0 m

pans), a larger four-point load platform was used. For the smaller experiments a three-point load

platform was used. For the largest fire tests, the 4.6 m x 4.6 m pan was placed directly on the floor.
4 Cold Climate - 22 M Facility 153

The load platform was not used in these experiments because of stability problems and flexing of the

steel pan.

The fuels (JP-5, JP-8), which were stored in steel drums were transported into the hangar via a fork

lift. Fuel was pumped from the fuel truck into calibrated buckets to measure the volume. Once

measured, the fuel was carefully poured from the buckets into the pan. This method of volume

measurement has an estimated uncertainty of +0.47 f (0.5 quarts), based on the error in reading the

fuel volume from the buckets, and any spillage occurring during fuel transfer. As an added precaution,

all activities concerning fuel transport was supervised by fire fighting personnel to safeguard the

operation.

For the larger full scale tests , fuel was pumped directly from 208 H (55 gal) drums into the pan. The

initial and residual volumes were measured using a calibrated measuring stick, basing volume on an

increment of depth and assuming a constant cross sectional area of the barrel. The estimated

uncertainty for this measurement was ±3.8 f (1 gal), based on the flexing of the drum when fuel was

added. This flexing created different cross sectional areas of the drum at different depths, reducing the

accuracy of these volume measurements. Since several drums of fuel were required for larger tests, the uncertainty stated should be included for each full drum of fuel. Another weight measurement was

recorded for initial weight of fuel in the pan. Once again, a check on the stability and center position of

the pan was made.

At this point a final check of all instrumentation was made. The floor based radiometer was positioned

at a predetermined distance from the pan. Each UV/IR detector was located at a measured position and

aimed at the fire pan using a small visible laser mounted on the side of the detector.

Building Check

The next step in the procedure was to confirm the position of hangar and side maintenance doors

throughout the hangar. Two experiments conducted required hangar doors to be partially open,

however, for the majority of the tests all doors were closed. Other openings such as office doors and

ventilation fan louvers were closed and secured. The base fire personnel were notified to stand ready.

For the larger fire tests, a charged hose line containing AFFF was brought into the hangar in case an emergency shutdown was necessary. Fire fighting personnel were provided protective suits and

breathing gear.

Countdown Sequence

Once all instrumentation, fuel pan and building checks were completed a countdown sequence was

started. The project leader notified all participants to enable their data systems and record necessary

ambient conditions. Personnel who operated hangar doors for post-test smoke evacuation were told to stand ready. Video cameras began recording. The data system used to measure temperatures,

sprinkler activation, and other fire parameters began recording background information.

The fuel in the pan was ignited using an acetylene torch. Ignition time was defined by sustained

burning of the fiiel when the torch flame was removed. A member of the test crew signaled ignition.

At this point, all data systems began recording or indicated ignition time within their data files. A

stopwatch was started at the time of ignition.
154 4 Cold Climate - 22 M Facility

During Tests

Visual observations of plume symmetry, smoke filling, smoke movement throughout the hangar, and

burning characteristics, including flame spread rate across the pan, were noted along with the elapsed

time. Photographs of important events which occurred during the experiment were taken and

documented. Throughout the experiment, safety temperatures (i.e., steel beam and fuel pan) were

monitored to ensure that structural integrity was not at risk. Also, smoke depth above the floor was

monitored. If any of these conditions surpassed established risk protocol or other serious conditions

arose, the project leader would terminate the experiment and take appropriate action to evacuate the

building and begin suppression procedures. If everything ran smoothly, the test continued for

nominally ten minutes or until temperatures near the ceiling reached equilibrium.

Suppression and Smoke Evacuation

Upon completion of the experiment, the project leader signaled the suppression crew to begin

extinguishment process. The suppression crew consisted of base fire personnel and team members with

fire fighting experience all equipped with required safety gear. CO2 type extinguishers were used to suppress the smaller fires. For the larger fires, a combination of CO2 extinguishers and a suppression

lid mounted on long handles was used. As the lid was lowered over the pan, CO2 was applied to the

flame, thus inerting the space underneath the lid. This method proved very efficient in not only

suppressing the fire but protecting the load platform electronics and without spilling large amounts of

fuel. For the larger fires, a4.9mx4.9m suppression lid was used. This lid was suspended from a boom connected to large fork truck, which was used to transport the lid and hoist it over the burning

pan. Once the lid was placed over the pan, a small port on the side of the lid was carefully opened and

CO2 was injected to suppress the fire. This method worked extremely well.

Once the fire was suppressed, personnel opened hangar doors to evacuate the smoke. During this time,

all nonessential personnel were evacuated from the building until the smoke abated. Members of the

fire fighting crew remained near the extinguished pan to ensure complete suppression and prevent

potential re-ignition of the fuel.

Data Reduction and Fuel Removal

Once the smoke had been evacuated, participants reentered the building and returned to their stations. Data systems were reset and files were transferred to backup media. Results were printed and graphed

for analysis. The residual fuel in the pan was removed once the temperature of the fuel decreased well

below its flash point. Small hand pumps were used to transfer the residual fuel into the calibrated

containers for final volume measurement. The fuel was then discarded into scalable steel drums and

removed from the building. The base hazard materials team performed all fiiel transfers and clean-up.

Discuss Results with Participants

The final process was to discuss the results from the previous experiment. Interesting events and

unusual behavior of instrumentation was also discussed. Participants evaluated instrumentation damage

and or changes required for the next experiment. The project leader was responsible for evaluating all results and planning the next experiment accordingly.
4 Cold Climate - 22 m Facility 155

Table 40. Test information for each experiment conducted in 22 m high facility

Test Date Time Pan Size Fuel Amb. Ign. Test Number Type Temp.

(°C)

Time

(s)

Duration

(s)

1 5/4/95 08:24 0.3 mx 0.3 m JP-5 10 43 674

_..,.,.„,.,....,.. 5/4/95 09:25 0.3 mx 0.3 m JP-5 10 86 693

3 5/4/95 10:52 0.6 m X 0.6 m JP-5 11 66 638

4 5/4/95 11:49 0.6 m xO.6 m JP-5 14

17

75

207

620

5 5/4/95 13:35 0.9 mx 0.9 m JP-5 621

6 5/4/95 14:51 0.9 mx 0.9 m JP-5 16 246 619

7 5/4/95 16:18 1.2mx 1.2m JP-5 16 87 609

8 5/4/95 17:49 1.2mx 1.2m JP-5 n/a 87 623

9 5/5/95 08:09 0.3 mx 0.3 m JP-8 9 71 610

10 5/5/95 09:08 0.6 m xO.6 m JP-8 9 129 618

11 5/5/95 09:58 0.6 m xO.6 m JP-8 9 91 613

12 5/5/95 11:08 0.9 mx 0.9 m JP-8 9 31 621

13 5/5/95 12:26 1.2mx 1.2m JP-8 11 39 629

14 5/6/95 09:58 2.5 m Diameter JP-5 12 639 641

15 5/6/95 13:33 3.0 m x3.0m JP-5 12 205 659

16^ 5/6/95 19:30 2.5 m Diameter JP-5 8 291 383

17 5/6/95 21:42 3.0 m x3.0m JP-8 11 51 668

18'' 5/8/95 10:36 2.0 m Diameter JP-5 10 127 679

19b,c 5/8/95 12:57 2.5 m Diameter JP-5 13 71 380

20'' 5/8/95 17:00 3.0 mx 3.0 m JP-5 14 457 665

21 5/9/95 13:12 4.6 m x4.6 m JP-5 14 211 294

22<' 5/9/95 18:15 4.6 m x 4.6 m JP-5 16 64 424

* Test conducted with two hangar doors open.

'' Ceiling jet diermocouple configuration

•^ Test conducted with one hangar door open.

"* Simulated spill test
156 4 Cold Climate - 22 m Facility

Twenty-two experiments were conducted in the 22 m high facility, using the above procedures for

each experiment. Table 40 contains a summary of information for each experiment. The date and time

along with pan size, fuel type, ignition time, and test duration are included.

4.2.4 Fuel Specifications

All experiments conducted in the 22 m high facility utilized JP-5 and JP-8 jet fuel. The JP-5 fuel for

the full scale tests was taken from on-base reserves. The JP-8 fuel was delivered to Keflavik Naval Air

Station from the United States Air Force. The base fuels department conducts certain standard tests on

each batch of fuel delivered to the base. The fuel properties for the JP-5 and JP-8 used in these

experiments as reported by the fuels department laboratory at Keflavik Naval Air Station are listed in

Table 41. These values were within acceptable range as defined in the military specification for JP-5

[5] and JP-8 [6].

Table 41. Fuel properties of JP-5 and JP-8 used in experiments

'

Fuel Sam]pies, 22 m High Facility

Reference

No.

95-047 95-048 95-049 95-050 95-041 95-042

Sample

:...,........__,.:,...,.,:,: """1P-5 JP-5 JP-5 JP-8 JP-8

Date Taken 3/8/95 5/9/95 5/4/95 5/6/95 4/28/95 4/28/95

API

Gravity @

15 °C

41.6 41.5 41.5 41.6 43.7 43.6

Specific

Gravity

0.8174 0.8179 0.8179 0.8174 0.8076 0.8081

Density

(kg/m^)

817.1 817.5 817.5 817.1 807.3 807.7

Flash Point

(°C)

62.8 63.3 63.3 62.8 45.6 47.8
4 Cold Climate - 22 M Facility 157

4.3 Behavior of Fires in 22 m High Hangar

There were twenty-two full-scale fire experiments performed in the Iceland hangar. As with the

Hawaii tests, these experiments were broken into detector fires (less than 2.8 MW) and sprinkler fires (greater than 2.8 MW). The behavior of these fires is described in the following sections.

4.3.1 Detector Fires

There were thirteen detector fires conducted in the 22 m high facility, eight fires using JP-5 aviation

fuel and five fires using JP-8 aviation fuel. All of the detector fires were conducted using square pans

supported by the three point load cell described earlier. The detector fires were ignited at one corner

of the fire test pan using an acetylene torch. The ambient fuel temperatures ranged from 9 °C to 17 °C. The time required for the fire to involve the full pan is presented in Table 42. Included in

Table 42 are the observed flame heights. These measurements were obtained through video analysis.

Plume Symmetry

The spacial location of the plume near the ceiling was determined using the regular array of

thermocouples located 0.3 m beneath the ceiling at radial positions of 0.0 m, 3.0 m, and 6.1 m in the

experimental N, S, E, and W directions from the geometric center of the fire. The initial position of

the plume near the ceiling was determined using the arrival time of the hot gas at each thermocouple

while later plume positions were deduced by comparing the relative temperature of symmetric pairs of

thermocouples in the N-S or E-W directions. An idealized plume should possess its highest

temperature on its center line with mixing of the entrained ambient air causing the temperature

distribution to decrease radially outward. The largest uncertainties in the determination of plume center would occur due to thermal irregularities in the plume and to the lack of simultaneity in the

thermocouple measurements. Pairs of thermocouples were typically separated by no more than 10 data

channels such that the lack of simultaneity was considerably less than the recording cycle of

approximately 3.1s. For the 0.3 m x 0.3 m pan fires, the low values of temperamre at the ceiling

make the determination of plume location difficult.

Videos of the fire taken using cameras looking east and southwest were used to determine the lean of

the flame and lower plume. While the location of the smoke plume at the ceiling was either not

available or difficult to determine owing to poor visibility at the ceiling, the lean of the flame and lower

plume could provide verification of the positions determined by the thermocouples at the ceiling. The

flame leans are determined based on the position of the tip of the continuous part of the flame

compared to the location of the edge of the fire pan. The amount of the lean is given in meters from

fire center. When the term 'slight lean' is used, the flame lean is less than 0.15 m. Measurements of

flame lean should be regarded as an estimate with an accuracy equal to about 0.25 of the pan diameter.

Two 0.3 m X 0.3 m test were conducted using JP-5 (tests 1 and 2). Video observations of test 1 indicated that the flame exhibited a northeast lean of 0.15 m at about 40 s into the test. At 100 s, the

flame leaned about 0. 15 m to the southeast and then to the south at about 140 s. At 170 s, fuel was

observed to be burning off the southeast corner of the pan. Small amounts of fuel were observed to be

burning off the south or southeast side of the pan up to 400 s into the test. The flame exhibited a northwest lean of about 0.3 m at 200 s, centered itself at 240 s, and then leaned 0. 15 m to the southeast

at 360 s. At 410 s, the flame again leaned 0.15 m to the northwest and then centered at 460 s.
158 4 Cold Climate - 22 M Facility

Thermocouple measurements at the ceiling suggest that the plume exhibited a slight lean to the south

between 80 s to 200 s into the test. This lean increased to about 3 m between 200 s to 500 s. The

increased lean coincided with observed burning of the fuel off the south side of the pan.

Video observations of test 2 indicate that the flame was initially centered but exhibited a 0.15 m lean to the northwest at about 25 s into the test. The flame centered 90 s into the test and then leaned 0.15 m

to 0.3 m to the south or southeast for the next 300 s. There was some burning of fuel off the south side

of the pan at about 100 s into the test and on the east side of the pan at about 500 s into the test. Thermocouple measurements at the ceiling suggested that the plume was centered. The signals

reflected the high turbulence levels in the plume, making the precise assessment of center position

difficult.

Two 0.6 m X 0.6 m tests were conducted using JP-5 (test 3 and 4). Video observations of test 3

showed that the flame leaned to the north or northwest from 20 s to about 430 s. The average flame

lean was about 0. 15 m but at 70 s, the lean appeared to increase to about 0.6 m. During the period of

maximum flame lean, there appeared to be some fuel burning off the north side of the pan. The flame was centered after 430 s.

Thermocouple measurements at the ceiling showed about a 1.5 m plume lean to the north between 40 s and 170 s. There was also a slight lean to the east between 100 s and 140 s. Between 180 s and 450 s, the plume was centered in the north - south directions and only leaned slightly to the west between

200 s and 280 s and again between 320 s and 500 s. The plume also exhibited a slight southward lean

between 460 s and 500 s.

The flame lean for test 4 was consistently to the north or northwest with the lean typically only 0.15 m.

At 300 s into the test, some fuel was observed burning off the northeast corner of the pan and the lean

increased to 0.3 m in the northwest for the next 90 s. At 580 s into the test, burning off the north side

of the pan occurred with the plume leaning as much as 0.6 m to the northwest. Thermocouple

measurements at the ceiling indicated only a slight lean in the north and east direction. Plume lean to the east occurred between 40 s and 300 s and again between 410 s and 500 s. Plume lean to the north

occurred between 60 s and 120 s and again between 260 s and 390 s.

Two 0.9 m X 0.9 m tests were conducted using JP-5 (Test 5 and 6). For test 5, there was an initial flame lean of 0. 15 m to the north with observed burning of fuel off the northwest side of the pan. The

north lean of the flame increased to 0.3 m at 110 s and then increased to 0.6 m and changed directions

to the northwest at 160 s. At 120 s, additional fuel burning off the north side of the pan was observed

but the flame was essentially centered. At 200 s, the plume started to rotate and produce a fire whirl.

Additional burning of fuel off the northeast corner occurred at 230 s but this burning only produced a 0.15 m flame lean to the north. By 240 s the plume became centered and the fire whirl dissipated. At

345 s into the test, additional fuel burning again occurred on the south side of the pan with the flame

leaning 0.3 m to the southeast. At 400 s, a fire whirl developed to the south with additional burning of

fuel off the south side of the pan. At 520 s, the flame centered and the fire whirl dissipated.

Thermocouple measurements at the ceiling show that the plume leaned about 1.5 m to the south

between 10 s and 30 s. At 80 s, the plume leaned to the north by as much as 3.0 m. The 3.0 m lean to the north reoccurred between 350 s and 460 s. In the east-west directions, the plume was initially

centered but then leaned to the east by as much as 3.0 m between 35 s and 70 s. The plume became
4 Cold Climate - 22 M Facility 159

upright between 80 s and 130 s and then leaned eastward about 1.5 m between 140 s and 330 s.

The flame for test 6 exhibited a 0.15 m lean to the northwest between 30 s and 55 s and again between

280 s and 350 s. At 420 s, a northwest lean occurred which reached a maximum of 0.45 m at about

450 s. Thermocouple measurements at the ceiling indicated only a slight lean to the south between 30 s and 50 s. Between 70 s and 260 s and again between 290 s and 320 s, the plume leaned slightly to the

north. In the east - west direction, the plume exhibited a slight lean to the west between 30 s and 40 s and again between 120 s and 140 s. It exhibited a slight lean to the east between 60 s and 90 s and

again between 160 s and 350 s.

Two 1.2 m X 1.2 m tests were conducted using JP-5 (tests 7 and 8). For test 7, the flame exhibited a lean of 0. 15 m to the southeast between 20 s and 1 10 s. At 215 s, the flame began to lean to the

northwest, reaching a maximum lean of 0.8 m to the northwest at about 220 s. At this time there was

burning of fuel off the north side of the pan. At 300 s, the flame became upright and remained that way until 335 s when the flame leaned 0.6 m to the north. The northward lean increased to about

0.9 m to the north west at 400 s. During this period, there was burning of fuel off the north side of

the pan. From 480 s to 600 s, the flame was upright. Thermocouple measurements at the ceiling

indicated that the plume exhibited only a slight lean to the north between 20 s and 90 s. In the east - west direction, the plume leaned slightly to the west between 100 s and 150 s and again between 220 s and 250 s. The plume leaned slightly to the east between 160 s and 210 s and again between 410 s and

500 s.

For test 8, the flame exhibited a slight north lean at 90 s which increased to 0.4 m to the northwest by

100 s. At 130 s, the flame became upright and with the exception of a 0. 15 m lean to the northwest

between 180 s and 420 s and again between 560 s and 580 s was upright through the rest of the test period. Thermocouple measurements were not available for this test due to an equipment malfunction.

The JP-8 tests were conducted on a day when strong winds in excess of 48 km/h (30 mph) were

observed. The impact of the wind on the hangar test fires was to produce consistently large plume

leans even though the building doors were closed during the tests. The wind blew consistently from

the south which resulted in observed plume leans in the north direction. Test 9 was a0.3mx0.3m

JP-8 pan fire. The flame leaned 0.8 m to the north for the entire test. Fuel burned off the north side of

the pan starting at 200 s into the test and continued to for the next 200 s. Smoke was observed filling

the north half of the curtained area first. Thermocouple measurements at the ceiling for this test indicated that the plume was centered for the first 250 s of the test and then leaned slightly to the north

for the test duration.

Test 10 was a0.6mx0.6m JP-8 pan fire. The flame leaned 0.5 m to the north at the start of the test. The flame lean increased to 0.9 m north by 50 s and was accompanied by burning off the north side of

the pan. The strong north lean continued throughout the rest of the test with occasional episodes of

burning off the north side of the pan. Thermocouple measurements at the ceiling indicated a north lean

of 1.5 m between 40 s and 60 s. This lean decreased in the north direction between 60 s and 100 s and

then increased to a lean of 1.5 m to 3.0 m to the north between 100 s and 500 s. The greatest north

lean occurred between 220 s and 260 s. There was also a slight eastward plume lean between 40 s and

370 s.

Test 11 was a repeated 0.6 m x 0.6 m JP-8 pan fire. The flames started with a slight north lean which
160 4 Cold Climate - 22 M Facility

increased to a lean of 0.8 m to the north by 50 s. At 70 s, burning was observed off the north side of

the pan which persisted till about 250 s. The flame consistently leaned 0.8 m to the north throughout

the rest of the test. Thermocouple measurements at the ceiling indicated that the plume was centered

for the first 300 s and then developed a slight east lean. Between 340 s and 370 s the plume was

upright and then leaned slightly to the east between 370 s and 440 s. The plume then remained upright

throughout the rest of the test.

Test 12 was a0.9mx0.9m JP-8 pan fire. The flame leaned slightly north at the start of the fire and

increased its lean to 0.8 m north at 80 s when burning off the north side of the pan was observed. At

90 s, a small fire whirl was observed to form at the northwest corner of the pan and lasted for about

20 s. The 0.8 m lean to the north persisted for the remainder of the experiment. Thermocouple

measurements at the ceiling indicated that the plume leaned between 3 m and 5 m to the north over the

duration of the experiment. The plume also leaned slighdy to the east between 400 s and 500 s.

Test 13 was a 1.2mx 1.2m JP-8 pan fire. The flame leaned 0.3 m to the north at the start of the fire. This lean increased to 0.9 m to the north at about 100 s into the fire and remained between 0.6 m and

0.9 m to the north for the duration of the fire. Burning off the north side of the pan produced a small

fire whirl approximately 70 s into the test. By 160 s, the fire whirl disappeared but there was still substantial burning of fuel off the north side of the pan. Thermocouple measurements at the ceiling

indicated that the plume leaned 3 m and 5 m to the north between 20 s and 410 s with the north lean

reducing to 3 m between 410 s and 500 s. The plume was upright in the east-west direction for the

entire test.

Temperature

The ambient temperature for each of the thirteen detector fires is listed in Table 43 . Ambient

temperamres for these tests ranged between 9 °C and 16 °C. Also listed in the table is the temperature

rise above ambient recorded by thermocouples located 0.3 m beneath the ceiling and radially at fire center and at 3.0 m to the north, south, east, and west of fire center (C, Nl, SI, El, and Wl). The

temperature values reported are based on analyzing the temperature range over the time interval where

the fire's mass loss rate appeared steady and choosing the value equal to ninety percent of the range.

In general, the ceiling temperature increases with time, hence the temperature values reported in the

table will typically be realized late in the test period. The temperatures reported in the table will not be

useful in determining plume symmetry with respect to the fire center, since the ninety percent

temperature values at each thermocouple could occur at different times as the plume center moves

around the ceiling. Also listed are the heat release rates and pan size for each fire.

Heat Flow

The impact of the draft curtain on smoke flow can be studied by comparing the time required for the

combustion products to produce a 3.0 °C temperature rise at thermocouples E7 and S7.

Thermocouple E7 was located 22.9 m (75 ft) from the geometric center of the fire 0.3 m (1.0 ft) beneath the ceiling along the curved portion of the ceiling. Thermocouple S7 was located 21.6 m (71

ft) from the geometric center of the fire and 0.3 m beneath the ceiling in the adjacent draft curtain bay

just before the second draft curtain. Since both thermocouples were located approximately the same

radial distance from the fire, time differences in the arrival of the hot gas would give an indication of

how effective the draft curtain was in containing heat and smoke. Figure 41 shows a comparison of the
4 Cold Climate - 22 M Facility 161

time required to produce a 3 °C temperature rise at thermocouples E7 and S7 as a function of heat

release rate (HRR) for the JP-5 pan fires. The detector fires, with heat release rates less than 3 MW,

produced substantial time differences in the two directions with the hot gas arriving at least 100 s earlier in the direction parallel to the draft curtain. The 0.3 m by 0.3 m pan fires were not included in

the figure because the temperature increases were insignificant at these large distances from the fire.

The JP-8 pan fires show a similar trend with the largest detector fire showing a 70 s difference in the

two directions. The hot gas flow for the JP-8 detector fires was impacted by strong winds blowing

outside the hangar as mentioned in the plume symmetry section. The ability of the draft curtains to contain the heat and smoke was only slightly modified by the induced air currents in the building.

Hot gas flow within the first draft curtain can be studied by using the set of 20 thermocouples located at radial distances south from fire center of 3.0 m, 4.6 m, 6.1 m, and 6.7 m and at distances beneath the

ceiling of 0.3 m, 1 .5 m, 3.0 m, 4.6 m, and 6. 1 m. The hot gas would be expected to flow radially

outward from plume center as a ceiling jet, be deflected downward by the draft curtain, lose buoyancy

and be drawn back toward the plume as shown in Figure 71. The effect of this circulation pattern

would be to create a low temperature volume in a central region between the plume and the draft

curtain. The temperature data from test 7, a 1.2 m x 1.2 m pan fire, provides an excellent example of

this flow. Table 44 presents the time necessary to reach a 3 °C temperature rise for each thermocouple

in the thermocouple array.

From the table it can be seen that thermocouple S3a, S2b, S3b, S2c, and S2d require the most time to reach 3 °C. This is consistent with the flow pattern shown in Figure 71. Other fire tests show similar

temperature profiles, but the feature is most easily visualized using the smaller tests as the large tests tend to quickly fill the draft curtain and cut off the flow of ambient air to the draft curtained region.

The flow of hot gas along the curved portion of the ceiling can be analyzed by comparing the 3 °C

temperature rise times for thermocouples El, E3, E5, and E7 at radial distances from fire center of 3.0

m, 9.1 m, 15.2 m, and 22.9 m as shown in Table 45. For the detector fires (less than 3 MW), it took

from 20 s to 44 s for the hot gas to move from thermocouple El to thermocouple E5. From

thermocouple E5 to thermocouple E7 it took from 28 s to 80 s for the hot gas to cover this distance.

The increased time for the hot gas to move between E5 and E7 indicates a substantial decrease in ceiling jet velocity.

Ceiling Jet Velocities

Ceiling jet velocities were measured using mass flow meters positioned at 6. 1 m and 12.2 m (20 ft and

40 ft) from fire center along the curved roof in the east direction. The mass flow meters were located

0.3 m beneath the ceiling. For the JP-5 tests, the 0.3 m x 0.3 m pan fires yielded a ceiling jet velocity

of about 0.25 m/s at 6. 1 m for both tests. The highest ceiling jet velocities were recorded for test 5, a 0.9 m X 0.9 m pan fire where the velocities early in the test reached speeds of about 1.4 m/s. Figure 72

presents the time history of these measurements for this 0.9 m x 0.9 m test fire. Typical ceiling jet

velocities for the three larger fires ranged from 0.6 m/s to 1.0 m/s with little evidence of dependence on fire size. With the exception of the smallest JP-5 test, measured ceiling jet velocity tended to be

larger early in the test. This is probably due to the formation of the layer with the subsequent loss of

buoyancy by the plume gases penetrating the layer. With the exception of 0.3 m x 0.3 m pan fires, the

ceiling jet velocities 12.2 m from fire center for all the JP-5 detector fires ranged between 0.2 m/s and
162 4 Cold Climate - 22 M Facility

0.4 m/s independent of fire size. The 0.3 m x 0.3 m pan fire produced a ceiling jet velocity of 0. 1 m/s

at 12.2 m east of fire center.

The JP-8 detector fires tended to exhibit higher ceiling jet velocities than the JP-5 test with the ceiling

jet velocities at 6.1 m from fire center ranging between 0.75 m/s and 1.2 m/s for the three larger tests. The ceiling jet velocity for these tests stayed relatively constant during the entire test and did not exhibit

the decrease in velocity with time observed for the JP-5 tests. The 0.3 m x 0.3 m JP-8 test exhibited

ceiling jet velocities at 6. 1 m of about twice the ceiling jet velocities for the JP-5 fires. At 12.2 m from

fire center, the larger three JP-8 fires yielded ceiling jet velocities in the range from 0.25 m/s to 0.5

m/s which again was somewhat higher than the JP-5 fires. It should be noted that the JP-8 fire plumes

were affected by windy conditions outside the hangar. These windy conditions are likely to be

responsible for the differences observed in the ceiling jet velocities between the JP-5 and JP-8 tests.

In all cases, the measured ceiling jet velocities are substantially smaller than theory would predict using

Alpert's correlations for a flat ceiling [31]. For the present experiments, the smoke flow at the ceiling

is obstructed by beams and trusses. The primary obstruction to the smoke flow is a series of ceiling

beams of width from 0.2 m to 0.3 m. These beams run perpendicularly to the flow direction measured

by the flow meters and are spaced every 1 .5 m to 2. 1 m on center. A series of trusses also running

perpendicular to the flow are positioned on top of the beams and are spaced at intervals ranging from

5.8 m to 6.4 m on center. Since the flow meters were positioned 0.3 m below the ceiling, the presence

of the ceiling beams of an equivalent width would be expected to reduce the flow velocities at these

elevations compared to the expected flow velocities from smooth ceiling calculations. A second factor

which may play a role in reducing the flow velocity is the ceiling curvature. The fire was centered over the highest part of the hangar ceiling. Smoke flow along the curved part of the ceiling would be

required to follow a downward sloping path and therefore be slowed by the buoyant forces of the fire.

Heat Flux Measurements

Heat flux was measured using three flux meters which are described in section 3. Due to the small

magnitude of the transducer output signal, the data collection system could only resolve a reading of

approximately 0.25 kW/m^; hence, only the flux meter Rl registered non-zero flux measurements for

the detector fires. Table 46 lists the average radiative flux by Rl as a function of detector position

from the center of the pan during steady-state burning.

For test numbers 1,2, and 9 the heat flux was below the measurable threshold of Rl. Plotting the heat

flux measurements from the JP-5 tests (5 - 7) and the JP-8 tests (10 - 13) where the detector positions were kept approximately constant, the flux appears to be comparable for both fuels. This comparison

is shown in Figure 73. Based on the average values of these measurements, it appears the intensity of

heat flux increases linearly with heat release rate. Figure 74 shows the measured thermal radiation with

respect to time for the 0.9 m x 0.9 m and 1.2 m x 1.2 m pan fires using JP-5 fuel. Figure 75 shows the

measurements for each detector fire using JP-8 with the exception of test 9. The heat flux radiometers

mounted at two positions near the ceiling did not indicate measurable levels of heat flux for these

detector fires.

Heat Release Rate

Heat release information for the 13 detector fires was calculated using time dependent mass loss data
4 Cold Climate - 22 M Facility 163

provided by the load platform. In addition, measurements of initial and final fuel volume were made.

This method of volume measurement has an estimated uncertainty of ±0.47 f (± 0-5 quarts), based on

the error in reading the fuel volume from the buckets, and any spillage occurring during fuel transfer.

The amount of fuel consumed by the fire was determined using both the load platform (direct mass loss

rate) method and volume consumed method. The heat release rate was then determined by multiplying

the measured mass loss of fuel by the heat of combustion of the fuel. Using the volume of fuel consumed method, an estimate of heat release rate was made by calculating the average mass loss,

using the density of the fuel multiplied by the measured volume, over the duration of the test. This

method of determining heat release rate included the volume consumed over the entire test. Since the

final volume was not measured until the residual fuel in the pan cooled to below its flash point, the total volume of fiiel consumed would include any losses due to fuel vaporization and minimal losses during

the extinguishment process. Table 47 shows calculated heat release rates using both methods of mass

loss measurement, burning rates, and steady state time interval.

The mass loss rate using the load platform method is provided for all thirteen detector fires with the

exception of test 8, which is not available due to equipment malfunction. For each test, a linear curve

fit was used to determine burning rate after an approximate steady state condition was reached. The

steady state condition was defined as the region on the mass loss curve where the slope was consistently

decreasing without major fluctuations.

There were difficulties in determining the steady state heat release rate values for several of the

detector experiments. These problems are attributed to fluctuations in the mass loss curves during the

early stages of the experiment. Fluctuations were caused by instrumental anomalies, non-uniform

burning, and burning outside of the pan in some cases. An effort was made to adapt high-order

polynomial curve fits that were representative of the time dependant mass loss rate. However, heat

release rates calculated from the derivative of these polynomials were very sensitive to small changes

in slope and showed poor agreement with the steady state heat release values.

To simplify the process, a steady state region was determined and the linear fit extended to the limits of

the steady state interval. It is important to realize that by changing the steady state interval, changes

may occur in the resultant heat release value. The uncertainty of the calculated heat release rates was

determined by evaluating upper and lower limits obtained by using curve fits during various portions of

the mass loss curve. Figure 76 shows the measured mass loss for test 7 and test 13 (1.2mx 1.2m

pans), the region where steady state was determined, and a linear curve fit of the steady state region.

The burning rate increased during the early part of the fire until a steady state condition was reached.

The time required to reach this condition varied with pan size with the larger pans

generally requiring more time to reach steady state. Figures 77 and 78 show the mass loss curves for

the 0.6 m x 0.6 m and 0.9 m x 0.9 m test fires using JP-5 and JP-8 fuels.

4.3.2 Sprinkler Fires

There were eight sprinkler fires conducted in the 22 m high facility, seven fires using JP-5 aviation fuel and one fire using JP-8 fuel. Two of the JP-5 fires were open door fires. All except one of the

sprinkler fires used the four point load cell. The 4.6 m x 4.6 m square pan was not rigid enough to be
164 4 Cold Climate - 22 m Facility

Table 42. Time to full-pan involvement and observed flame heights for detector fires

Test NumberFuel

Type

Pan Size

m

Time to Full

Involvement

s

Flame

Height

m

Steady State Heat

Release Rate

MW

Steady State Range

s

JP-5 0.3x0.3 0.9 0.1 120 - 600

JP-5 0.3x0.3 0.9 0.1 150 - 600

JP-5 0.6x0.6 15 2.0 0.9 120 - 360

JP-5 0.6x0.6 15 1.8 0.8 125-420

JP-5 0.9x0.9 20 2.6 1.7 90 - 330

JP-5 0.9x0.9 20 2.5 1.4 120 - 420

JP-5 1.2 X 1.2 30 3.5 2.8 150 - 420

JP-5 1.2 X 1.2 30 3.3 n/a" n/a"

JP-8 0.3x0.3 0.7^ 0.2 120 - 450

10 JP-8 0.6x0.6 15 1.4^ 0.6 120-510

11 JP-8 0.6x0.6 15 1.3" 0.8 120 - 450

12 JP-8 0.9x0.9 20 2.0" 1.6 180 - 420

13 JP-8 1.2 X 1.2 30 2.4" 2.7 120 - 420

" Significant plume

'' Data not available

and flame lean

due to equipment malfunction
4 Cold Climate - 22 m Facility 165

Table 43. Temperature data for 22 m high faciUty detector fire tests

Test Information Temperature Data (°C)

Test

Number

Pail Size

m

•amb Steady State Heat Release

Rate, MW

'"""""C""""" Nl SI Wl El Max.

Value

Rise : Above %

T^ amb Test 1 0.3x0.3 10 0.1 13 12 13 13 13 13 3 Test 2 0.3x0.3 10 0.1 13 13 13 13 13 13 3

Tests 0.6x0.6 11 0.9 20 20 19 20 19 20 9

Test 4 0.6x0.6 14 0.8 22 21 21 21 21 22 8

Tests 0.9x0.9 17 1.7 29 30 29 29 30 30 13

Test 6 0.9x0.9 16 1.4 33 32 33 32 32 33 17

Test? 1.2 x 1.2 16 2.8 47 46 45 45 45 47 31

Test 8^ 1.2 X 1.2 n/a n/a n/a n/a n/a n/a n/a n/a n/a

Test 9^ 0.3x0.3 9 0.2 11 11 11 11 11 11 2

Test 10" 0.6x0.6 9 0.6 17 18 17 18 18 18 9

Test 11" 0.6x0.6 9 0.8 17 18 16 17 17 18 9

Test 12 0.9 X 0.9 9 16 26 27 24 25 26 27 18

Test 13" 1.2x1.2 11 2.7 36 38 34 36 36 38 27

^ Data for test 8 not available due to equipment malfunction

" JP-8 aviation fuel used

Table 44. Time for hot gas to fill draft curtain volume based upon 3 ° C temperature rise for

south array of thermocouples for test 7 (1.2 m x 1.2 m, JP-5 fuel, 2.8 MW HRR)

Depth Below

Ceiling

Radial Distance From Center

south 3.0 m south 4.6 m south 6.1 m south 6.7 m

0.3m 26 s 26 s 34 s 34 s

1.5 m 26 s 34 s 42 s 34 s 3.0 m 34 s 58 s 58 s 34 s 4.6 m 38 s 46 s 34 s 34 s 6.1m 34 s 58 s 46 s 46 s
166 4 Cold Climate - 22 m Facility

Table 45. Hot gas transport times along east direction of ceiling

Test Number

Test 3

Pan Size

m

0.6x0.6

HRR

MW

0.9

El

Transport Times (s) E3 E5

93.3 97.3

E7

177.5

Test 4 0.6x0.6 0.8 77.4 101.2 101.2 196.5

Test 5 0.9x0.9 1.7 33.7 56 56 83.3

Test 6 0.9x0.9 1.4 34.3 61.5 61.5 120.5

Test 7 1.2 X 1.2 2.8 26 42.1 54.2 82.4

Test 10^ 0.6x0.6 0.6 42.4 91.6 112.2 218.8

Test IP 0.6x0.6 0.8 54.3 102.6 102.6 187.8

Test 12^ 0.9x0.9 1.6 34.5 42.6 66.8 103.2

Test 13^ 1.2x 1.2 2.7 26.6 38.6 54.7 90.9

^ JP-8 aviation fuel used

Table 46. Heat flux measurements for detector fires

Pan Size Heat Release Location with Respect to Pan Radiative Flux, Test m Fuel Rate Center, m(± 0.1) Rl

Number MW(± 0.1) Distance Height KW/m^ (±0.25)

3 0.6x0.6 JP-5 0.9 4.4 1.6 1.0

A A /c -.r A /; Tr> c A O n c 1 c A TC 4 U.D X U.O Jr-5 0.0 7.6 1.6 \j.Lj

5 0.9x0.9 JP-5 1.7 3.7 3.5

6 0.9x0.9 JP-5 1.4 3.7 3.0

7 1.2 X 1.2 JP-5 2.8 3.7 4.5

10 0.6x0.6 JP-8 0.6 3.8 1.5

11 0.6x0.6 JP-8 0.8 3.8 1.5

12 0.9x0.9 JP-8 1.6 3.8 3.5

13 1.2 X 1.2 JP-8 2.7 3.8 5.5
4 Cold Climate - 22 m Facility 167

Table 47. Heat release information for detector fires in 22 m high facility

Test Pan Si/e Fuel Eff Res. Volume

H

Burn Rate

(vol.)

kg/m^s

Bum Rate

(load)

kg/m^s

HRR

(vol.)

MW

HRR

(load)

MW

SS Range

s

Pan Dia.

m

Number

m

+0.47 ±0.001 ±0.001 ±0.1 ±0.1

1 0.3x0.3 JP-5 0.34 3.1 0.0409 0.0233 0.2 0.1 110-607

J 2 0.3x0.3 JP-5 0.34 3.3 0.0429 0.0199 0.2 0.1 150 - 600

3 0.6x0.6 JP-5 0.68 7.6 0.0266 0.0601 0.4 0.9 120 - 360

4 0.6x0.6 JP-5 0.68 9.5 0.0342 0.0496 0.5 0.8 125 - 420

5 0.9x0.9 JP-5 1.02 22.7 0.0364 0.0486 1.3 1.7 90 - 330

6 0.9x0.9 JP-5 1.02 22.7 0.0366 0.0400 1.3 1.4 120 - 420

7

o 1.2x 1.2

1 O V 1 o

JP-5

TD ^

1.35

1 1^

48.3

A^ A

0.0444 n n/IAQ0.0454 2.8 2.8 150 - 420

O

9

i.Z X l.Z

0.3x0.3

Jr-J

JP-8 0.34

4D.4

1.9

U,U4Uy

0.0278

n/a

0.0461

2.

J

0.1

n/a

0.2

n/a

120 - 450

10 0.6x0.6 JP-8 0.68 10.4 0.0378 0.0386 0.6 0.6 120-510

11 0.6x0.6 JP-8 0.68 10.4 0.0381 0.0499 0.6 0.8 120 - 450

12 0.9x0.9 JP-8 1.02 27.4 0.044 0.0465 1.5 1.6 180 - 420

13 1.2 X 1.2 JP-8 1.35 49.2 0.0438 . 0.0429 2.7 2.7 120 - 420

^ Data not available due to equipment malfunction

Table 48. Time to full-pan involvement and observed flame heights for sprinkler fires

Test NumberFuel

Type

Pan Size

m

Time to Full

Involvement

s(±5)

Flame

Height

m

Steady State Heat

Release Rate

MW

Steady State Range

s 14a JP-5 2.5 dia. 50 5.1 +0.5 7.9 120 - 420

15 JP-5 3.0x3.0 65 6.1±0.5 15.7 330 - 600

16^ JP-5 2.5 dia. 50 5.0 +0.5 180 - 270

17 JP-8 3.0x3.0 50 6.0 +0.5 14.3 270 - 540

18 JP-5 2.0 dia. 40 4.5 ±0.5 4.9 180 - 420

I9bc JP-5 2.5 dia 50 4.7 ±0.5 9.1 120 - 420

20 JP-5 3.0x3.0 65 6.1 ±0.5 14.6 240 - 540

21 JP-5 4.6x4.6 80 10 +1 33*^ n/a

Both hangar doors open fully

North hangar door open fully

Significant plume and flame lean

Heat release rate extrapolated from previous test data
168 4 Cold Climate - 22 m Facility

700

600

SOO

400

300

200

100

0.9 MW

Te«t3

0.8 MW

Test 4

1.7 MW

Tests

1.4 MW

Tecte

2.8 MW

Test 7

Figure 70. Comparison of smoke fill times for thermocouples E7 (22.9 m east) and S7 (21 .6 m south) for detector fires.
4 Cold Climate - 22 m Facility 169

6.7 m 6.1 m l»S4

i, •sAa ©Saa • S2a •Sla '<r^ 1.5 r

Draft Curtain

4.6 m

I

I Center r

S2 •si ^fX'-^Sm

• S4b A •S3b

i •S4c •S3c

\

^ •S4d •S3d

t • S2b I ©SI "

t

b-<f>- 3.0 m

I

' S2c

• S2d

•S1c<4>

•Sld <*>• 6.1 I

South Smoke Filling Thermocouple Array

Ceiling

Smoke Fill Thermocouple

Direction of Smoke Flow

Fire Pan

Figure 71 . Diagram of typical early stage hot gas flow in 22 m high facility.
170 4 Cold Climate - 22 m Facility

1.75

1.50 -

1.25

-§ 1.00 o

o>

i 0.75

O

0.50

0.25

Test 5, 0.9 m 0.9 m, JP-5 —o— V-i @6.1 meast

^i^ Vj @ 12.2 meast

0.00

120 240 360

Time (s)

f

Figure 72. Measured ceiling jet velocities for test 5, conducted in 22 m high facility.
4 Cold Climate - 22 m Facility 171

4

-

r>j

.-2 3

0)>

(0 TS

(0

Radiometer R1

Located (3.7 - 3.8) m from Pan Center, 1.1 m High

Linear Regression

Heat Release Rate (MW)

Figure 73. Average radiative flux values for detector fires using JP-5 and JP-8.
172 4 Cold Climate - 22 m Facility

03

0) X

1 80 240

Time (s)

480

Figure 74. Heat flux measurements for detector fires using JP-5 fuel.
4 Cold Climate - 22 m Facility 173

7.5

5.0

X3

(0

(U X

2.5 -

-e— Test 10, 0.6 m x 0.6 m, JP-8

-• - Test 11, 0.6 mx 0.6 m

-^— Test 12, 0.9 m X 0.9 m

-T-- Testis, 1.2 mx 1.2 m

1 f/

t w

W ^

V in J t

\

» u

T I

1

1

60 120 1 80 240

Time (s)

300 360 420 480

Figure 75. Heat flux measurements for detector fires using JP-8 fuel.
174 4 Cold Climate - 22 m Facility

140

135

130

-a 125

o 120 w

03 2 115

110

105

100

105

100

95

90

85 -

80 -

75

70

65

-60

Burn Rate = 0.045 kJ/m s HRR = 2.8 MW

Test 7, 1 .2 m X 1 .2 m Pan, JP-5 Mass Loss (kg) Linear Fit of Steady State Region

(150 to 420) s

-,

\

1

\

1

1

^

1

1

1

1

1

1

\

1

1

1

\

1 1

-60 60 120 180 240 300 360 420 480 540

Time (s) (A)

Burn Rate = 0.043 KMrvt s HRR = 2.7 IVIW

Test 1 3, 1 .2 m X 1 .2 m Pan, JP-8 Mass Loss (kg) Linear Fit of Steady State Region

(120 to 420) s

60 120

I

'

I

'

I 180 240 300

Time (s) (B)

—] '

\

'

1

'

1 360 420 480 540

Figure 76. Mass loss and linear curve fit for test 7 (A). Mass loss and linear curve fit for test 13 (B).
4 Cold Climate - 22 m Facility 175

V)o

_J

(0

CO

-| 1

\

I

I

I

I

I

I

^

I

,

\

I

1

^

1 r -60 60 120 180 240 300 360 420 480 540 600

Time (s)

Figure 77. Mass loss curves for 0.6 m x 0.6 m and 0.9 m x 0.9 m test fires using JP-5 fuel.
176 4 Cold Clin4ate - 22 m Facility

80

70 -

60

w

o 50 w

(/) TO

40 -

30

20

Test 10, 0.6 m X 0.6 m Pan, JP-8

Test 1 1, 0.6 m X 0.6 m Pan, JP-8

Test 12, 0.9 m X 0.9 m Pan, JP-8

—

\

1

\

1

\

^

\

<

1

1

1

'

\

1

I

'

I r—

1

^

60 60 120 180 240 300 360 420 480 540 600

Time (s)

Figure 78. Mass loss curves for 0.6 m x 0.6 m and 0.9 m x 0.9 m test fires using JP-8 fuel.
4 Cold Climate - 22 m Facility 177

160

140

120

100

I

80

60

40

20

H H H 1 I ^ I " ^ I 1 I "^ I H

iE7

IS7

7.9 MW 157 MW 7 0MW 14 3MW 4 9MW 9 1 MW 14 6MW 33 MW

Test 14 Test 15 Test 16 Test 1Test 1Test 19 Test 20 Test 21

Figure 79. Comparison of hot gas fill times at E7 (22.9 m east) and S7 (21 .6 m south).
178 4 Cold Climate - 22 m Facility

220

200

180

160

140 -

120 - oo

5

E 100

0)

80 -

60

40 -

20

Thermocouples at 12.2 m east —e— TC - E4, 0.3 m below ceiling —^

- TC - E4b, 0.4 m below ceiling —^— TC - E4c, 2.0 m below ceiling — -- TC - E4cl, 3.5 m below ceiling

, /> r^, / ^v

'\

-1—I—I—p60 120 180

Time (s)

240 300

Figure 80. Temperature profiles of heat flow near ceiling for 4.6 m x 4.6 m pan test using

thermocouples located 12.2 m east of fire center.
4 Cold Climate - 22 m Facility 179

220

200

180

160

140

o

°- 120

(UE 100

80

60

40 -

20

Thermocouples at 9.1 m east -e— TC - E3, 0.3 m below ceiling -r - TC - E3b, 1.2 m below ceiling -^— TC - E3c, 2.8 m below ceiling

- - - TC - E3d, 4.3 m below ceiling

1 1 r T -I 1 r 60 120 180

Time (s)

240 300

Figure 81. Temperature profiles at 9.1 m east of fire center for 4.6 m x 4.6 m test fire.
180 4 Cold Climate - 22 m Facility

2.00 -

1.75

1.50

(0 1.25

E - ^'o

o

0) >

0) 1.00

—)

O)co

o

0.75 -

0.50 -

0.25

0.00

e— V, , Test 15, 3.0 m x 3.0 m pan, JP-5 — V^, Test 21 , 4.6 m X 4.6 m pan, JP-5

180 240 300 360 420 480 540 600

Time (s)

Figure 82. Measured ceiling jet velocities for 3.0 m x 3.0 m and 4.6 m x 4.6 m test fires.
4 Cold Climate - 22 m Facility 181

2.00

1.75

1.50

1.25

oo^ 1.00

0) —i

O)

.cO

0.75

0.50

0.25

-e— v., , 6.1 m east, 0.3 m below ceiling Test 18, 2.0 m dia. pan, JP-5

Hi - Vj , 12.2 m east, 0.3 m below ceiling Test 18, 2,0 m dia. pan, JP-5

0.00 l^ fT^ 1

1 1 1 1 1

1

1 1 1 1 1

1

1 1 1 1 1

1

1 1 1 1 1

1

1 1 1 1 1

1

1 1 1 1 1

1

1 1 1 1 1

1

1 11 1 1

1

1 1 1 1 1

1

60 120 180 240 300 360 420 480 540 600

Time (s)

Figure 83. Measured ceiling jet velocities for 2.0 m diameter test fire.
182 4 Cold Climate - 22 m Facility

40

30 -

20 -

-e— E3Ja

-r - E3Jb

-D— E3Jc --- E3Jd

Depth Below Ceiling

E3Ja -0.15 m

E3-0.3 m

E3Jb-0.45 m

E3Jc - 0.61 m

E3Jd -0.76 m

E3Je -0.91 m

x.

-1—I—I—I—I—p15 30

9.1 m east

40

45 60 75 90 105 120

12.2 m east

-1 1

1 1 1 1——I r— 1 1 n

15 30 45 60 75 90 105 120

120

Time (s)

Figure 84. Temperature profiles of ceiling jet region for 2.0 m diameter test fire (test 1 8).
4 Cold Climate - 22 m Facility 183

80

li 60

2!

*-< CD

L_0)Q.E

40 -

20

E4Ja

E4

E4Jb

-*-- E4Jc

* E4Jcl -- E4Je

15

Oo

0)

k-a>Q.E

80 -

60

40

20

120

30

15 30

12.2 meast

45 60 75 90 105 120

15.2 m east

45

"^

\ ^

60

Time (s)

75 90 105 120

Figure 85. Temperature profiles of ceiling jet region for 3.0 m x 3.0 m test fire (test 20).
184 4 Cold Climate - 22 m Facility

40

30

o

I 20

<DQ.E

0)

E3Ja - 9.1 m east E4Ja- 12.2m east E5Ja- 15.2 meast

Depth Below Ceiling = 0.15 m

15

~1 ''

\

'

' T" 30 45 60 75

40

30

o

I 20

Q.E

10

-&— E4- 12.2 meast

-^ - E5- 15.2 meast

Depth Below Ceiling = 0.3 m

n \ 11 n 15

T

30 45 60

Time (s)

75

90

90 105

105 120

120

Figure 86. Ceiling jet temperature profiles at a depth of 0. 1 5 m and 0.3 m below the ceiling

for the 2.0 m diameter test fire.
4 Cold Climate - 22 m Facility 185

40

30

oo

I 20

0)Q.E

(D H10

-e— E3Jb-9.1 meast ^ - E4Jb- 12.2 meast

-a— E5Jb- 15.2 meast

Depth Below Ceiling = 0.46 m

n 1 1 1 r I 1 n 1 1 1 r

40

30

15 30 45 60 75 90 105 120

O

I 20

0)Q.E

0)

10

-e— E3JC-9.1 meast

-^ - E4Jc- 12.2 meast

-D— E5Jc - 15.2 m east

Depth Below Ceiling = 0.61 m

~i 11

1 1

1

1 r 15 30 45

" ' T" 60 75

~i 1

1

1 r 90 105 120

Time (s)

Figure 87. Ceiling jet temperature profiles at a depth of 0.46 m and 0.61 m below the ceiling

for the 2.0 m diameter test fire.
186 4 Cold Climate - 22 M Facility

supported by the four point load cell and was therefore placed directly on the hangar floor. The

sprinkler fires were ignited at one corner of the fire pan using an acetylene torch. The ambient ftiel temperatures ranged from 9 °C to 17 °C. The time required for full pan involvement of each pan fire and observed flame heights are given in Table 48.

Plume Symmetry

The spatial location of the plume near the ceiling was determined using the regular array of

thermocouples and the video images. Test 14 was a 2.5 m diameter JP-5 pan fire. The flame was

upright for nearly the entire test showing only a 0.3 m lean to the west from 90 s to 360 s and a slight

south lean after 520 s. Thermocouple measurements at the ceiling indicated that the plume had a slight

south lean between 70 s and 80 s, 150 s and 200 s, and 300 s and 500 s. In the east-west directions,

the plume leaned slightly west between 300 s and 330 s and then leaned slightly east between 410 s and

440 s.

Test 15 was a3.0mx3.0m JP-5 pan fire. The fire was lit in the northwest corner of the pan and the

smoke was observed to move straight upward during the entire test. The flames stayed upright during

the entire test. At 350 s, a small amount of fuel was observed to be burning off the south side of the

pan. Temperature measurements at the ceiling indicated that between 30 s and 50 s, the plume

exhibited a slight west lean. Between 60 s and 260 s, the plume began to lean to the south, reaching

1.5 m south between 150 s and 200 s. The plume righted itself at 260 s and then only exhibited slight

south leans between 310 s and 360 s and again between 470 s and 500 s. In the east-west directions,

the plume leaned slightly to the west until 80 s when it took on a slight east lean. At 140 s, the plume

righted itself but between 230 s and 500 s, the plume leaned 1.5 m to the east.

Test 16 was an open door test and is described later in this section.

Test 17 was a3.0mx3.0m JP-8 pan fire. The fire was lit in the northwest corner of the pan and the

smoke was observed to move straight upward during the entire test. The flame was also upright during

the entire test. Temperature measurements at the ceiling indicated that in the north - south direction,

the plume exhibited a slight lean to the south at 60 s to 80 s, 1.10 s to 140 s, 270 s to 310 s, and 360 s to 500 s. In the east - west direction, the plume leaned 1 .5 m to the east for the duration of the test.

Test 18 was a 2.0 m diameter JP-5 pan fire. The fire was lit on the north side of the pan and leaned

0.3 m to the north for the first 40 s of the test. At about 40 s, there was substantial burning of JP-5

outside the pan to the north which was extinguished at 1 10 s. Between 50 s and 100 s, the flame was

upright. At 100 s, the flame began to lean to the northwest reaching 0.6 m at 200 s. For the rest of

the test, the flame exhibited a northwest lean of 0.3 m to 0.6 m.

Temperature measurements for this test indicated that in the north - south direction, the plume leaned

1 .5 m to the north at 40 s to 60 s, 120 s to 230 s, 260 s to 300 s, and 380 s to 500 s. The plume leaned

1.5 m to the south between 350 s and 370 s. In the east - west direction, the plume leaned slightly to the west for the entire test duration.

Test 19 was another open door test and is described later in this section.
4 Cold Climate - 22 M Facility 187

Test 20 was a3.0mx3.0m JP-5 pan fire. Only the video camera looking east was available for this

fire. The fire was lit in the northwest corner with the smoke initially moving straight up. At 170 s, the

flame developed a 0.6 m north lean which became upright at 190 s. Temperature measurements at the

ceiling indicated that in the north - south direction, the plume was initially centered and only exhibited

a slight south lean between 35 s and 160 s and again between 240 s and 400 s. In the east-west

directions, the plume leaned 1.5 m west between 20 s and 150 s and then gradually became upright at 230 s.

Test 21 was a4.6mx4.6m JP-5 pan fire. The fire was lit in the northwest corner of the pan and the

smoke moved vertically upward. Thermocouples mounted at the ceiling indicated that in the north - south direction, the plume leaned 3 m north at 30 s to 70 s and at 160 s to 250 s. The plume leaned

to the south at 70 s to 120 s. In the east - west direction, the plume leaned slightly to the west at 30 s to 45 s and 65 s to 75 s. The plume leaned 1.5 m to the east between 75 s and 140 s and 4.0 m to the

east between 75 s and 140 s. Between 210 s and 260 s, temperature spikes were recorded on the Wl

thermocouple but both the El and E2 thermocouples recorded higher temperamres than the W2

thermocouple indicating that the plume was leaning to the east. The temperature spikes recorded on Wl were due to intermittent flames impinging on the thermocouple.

Temperature

The ambient temperature for each of the eight sprinkler fires is listed in Table 49. Ambient

temperatures for these tests ranged between 8 °C and 14 °C. Also listed in the table is the

temperature rise above ambient recorded by thermocouples located 0.3 m beneath the ceiling (C, Nl,

SI, El, and Wl) radially at fire center and at 3.0 m to the north, south, east, and west of fire center. The temperature values reported are based on analyzing the temperature range over the time interval

where the fire's mass loss rate appeared steady and choosing the value equal to 90 % of the range. In

general, the ceiling temperature increases with time, hence the temperature values reported in the table

will typically be realized late in the test period. The temperatures reported in the table will not be

useful in determining plume symmetry with respect to the fire center, since the ninety percent

temperature values at each thermocouple could occur at different times as the plume center moves

around the ceiling. Also listed in the table is the calculated heat release rate and pan size for each

experimental fire size.

Test 21 was the4.6mx4.6m(15ftx 15 ft) JP-5 pan fire. The high temperature recorded in the table

for the Wl thermocouple was probably due to intermittent flames striking that thermocouple. This

assumption is based on the observed temperature spikes exhibited by the data rather than a more

constant temperature profile that is exhibited by the other thermocouples. Thermocouples C and Nl

should be used to determine the gas temperature near plume center.

Heat Flow

The impact of the draft curtain on hot gas flow can be studied by comparing the time required for the

hot gas to produce a 3.0 °C temperature rise at thermocouples E7 and S7. Thermocouple E7 was

located 22.9 m (75 ft) from the geometric center of the fire 0.3 m beneath the ceiling along the curved

portion of the ceiling. Thermocouple S7 was located 21 .6 m (71 ft) from the geometric center of the

fire and 0.3 m beneath the ceiling in the adjacent draft curtain bay just before the second draft curtain.

Since both thermocouples were located approximately the same radial distance from the fire, time
188 4 Cold Climate - 22 M Facility

differences in the arrival of the hot gas would give an indication of how effective the draft curtain was

in containing heat and smoke. Figure 79 shows a comparison of the time required to produce a 3 °C

temperature rise at thermocouples E7 and S7 as a function of heat release rate (HRR) for the JP-5 pan

fires. The sprinkler fires, with heat release rates greater than 4 MW, produced hot gas arrival times of

32 s to 65 s earlier in the direction parallel to the draft curtain compared with the direction

perpendicular to the draft curtain. Once the heat release rate exceed 7 MW, the arrival time difference

became independent of heat release rate.

The single JP-8 pan fire, test 17, showed a 28 s difference in the two directions. The JP-8 fire reached

full pan involvement in 50 s which was 15 s faster than the comparable JP-5 fires. The more rapid

flame spread across the pan may be responsible for the smaller time difference observed in the two

directions based on a more rapidly growing fire in the test.

The flow of hot gas along the curved portion of the ceiling can be analyzed by comparing the 3 °C

temperamre rise times for thermocouples El, E3, E5, and E7 at radial distances from fire center of 3.0

m, 9.1 m, 15.2 m, and 22.9 m as shown in Table 50. The times shown in the table represent the actual

elapsed time from ignition as recorded by the data collection system. Since the average time interval

between channel scans was approximately 4 s, the response times shown may differ by this amount.

For the sprinkler fires, it took from 18 s to 24 s for the hot gas to move from thermocouple El to thermocouple E5. From thermocouple E5 to thermocouple E7 it took from 13 s to 24 s for the hot gas

to cover this distance. The ceiling jet slows down substantially as it traverses the distance between El

and E7.

The impact of the hot gas flow interacting with the ceiling beams produced an unexpected temperature

distribution as a function of height. Using data from Test 21 which produced the highest ceiling

temperatures. Figure 80 displays the temperature as a function of height measured by the thermocouple

tree located at 12.2 m east from fire center. During the first 120 s of the fire the highest temperatures

recorded were near the ceiling but after 120 s, the hottest temperatures are found at thermocouple E4d

which is located 3.5 m below the ceiling and the thermocouple 0.3 m below the ceiling recorded the

coolest temperature. This thermocouple tree was located directly behind one of the ceiling beams

which obstructed the flow along the ceiling.

Figure 81 displays the temperature as a function of height for the thermocouple tree located at 9. 1 m

east from fire center. This thermocouple tree was not located behind a beam. The temperature history

provided by these thermocouples shows the highest temperatures are located near the ceiling with the

temperatures recorded by each thermocouple approaching similar values as the smoke layer deepens.

The unique temperature distribution recorded by the thermocouples located 12.2 m from fire center is assumed to be a result of the proximity of the beam altering the flow. There is also a possibility of the

curved ceiling playing a role but without another thermocouple tree located further away from fire center, this speculation cannot be pursued.

Ceiling Jet Velocities

Ceiling jet velocities were measured using mass flow meters positioned at 6. 1 m and 12.2 m from fire center along the curved roof in the east direction. The mass flow meters were located 0.3 m beneath

the ceiling. Figures 82 and 83 present the time history of these measurements. The ceiling jet velocity

for all the closed door tests usually reached its maximum value during the first 50 s of the test. The
4 Cold Climate - 22 M Facility 189

maximum measured ceiling jet velocity ranged from 1.0 m/s to 1.7 m/s for these sprinkler fires.

Ceiling jet velocities for the 3.0 m x 3.0 m test (test 15) exhibit large drops in velocity roughly 100 s into the test as shown in Figure 82. The ceiling temperatures at the velocity measurement locations did

not exceed 200 °C during these tests. Had the temperatures exceeded 200 °C, the temperamre

compensation range of the hot-wire anemometer would have also been exceeded. The low velocity

measurements are probably the result of loss of buoyancy by the plume as it tries to penetrate the hot

gas layer. The loss of buoyancy seems to have less effect on the flow patterns developed during the

2.0 m diameter test fire (test 18). Figure 83 indicates a higher measured velocity for this case.

The 4.6 m X 4.6 m test fire produced the highest measured velocity. However, according to the

velocity measurement as shown in Figure 82 , the ceiling jet velocity for this large test dropped to zero 80 s into the test and remained at zero until the fire was extinguished. This test produced ceiling

temperatures in excess of 200 °C which exceeded the temperature compensation range of the hot-wire

anemometer. As soon as the center temperature dropped below 200 °C, the mass flow meter began

recording nonzero velocities. The zero velocity readings are therefore regarded as an instrumental

effect based on high temperatures and should be discounted.

As in the case of the detector fires, the measured ceiling jet velocities are smaller than theory would

predict using Alpert's correlations for a flat ceiling [31], because the hot gas flow at the ceiling is obstructed by beams and trusses.

The thermocouple configuration at the ceiling was changed for tests 18 through 20 such that the

temperature profile of the ceiling jet could be measured. Thermocouples placed 0.15 m, 0.3 m,

0.45 m, 0.61 m, 0.76 m, and 0.9 m (0.5 ft, 1.0 ft, 1.5 ft, 2.0 ft, 2.5 ft, and 3.0 ft) below the ceiling were located radially from fire center at 9.1 m, 12.2 m, and 15.2 m (30 ft, 40 ft, and 50 ft). The

thermocouples (E3, E3Je) located 0.3 m and 0.9 m below the ceiling at a radial distance of 9. 1 m east

failed during these tests. Figures 84 and 85 provide temperature history of the ceiling jet during the

first 120 s of test 18 and test 20. The thermocouple tree located at 12.2 m was directly behind a ceiling

beam whereas the other two thermocouple trees were located midway between the ceiling beams. Both

test 18 and test 20 were JP-5 fires with test 18 reaching a steady state heat release rate of 4.9 MW and

test 20 reached a steady state heat release rate of 14.6 MW.

For test 18, the highest temperatures during the first 120 s were consistently recorded by the

thermocouples located at 0.76 m beneath the ceiling for all radial positions. Only at radial position

15.2 m did the thermocouple at 0.9 m reach similar temperatures. Lower temperatures were recorded

by thermocouples located at 0.15 m below the ceiling for all radial positions. The impact on the

temperature caused by the presence of the beam at 12.2 m is easily seen by comparing the temperatures

recorded by the two thermocouples located 0. 15 m and 0.45 m beneath the ceiling at all three radial

positions. For the thermocouple positions located midway between the beams (i.e., 6.1 m and 15.2 m),

the temperatures measured by the two thermocouples agree to within 1 °C. The thermocouple located

behind the beam at 0.15 m (0.5 ft) beneath the ceiling consistently recorded substantially lower

temperamres than the temperature at 0.45 m (1.5 ft) beneath the ceiling. Since the beam is approximately 0.3 m deep, the thermocouple closest to the ceiling is in the shadow of the beam

resulting in temperatures at this position being substantially lower. The thermocouple at 0.45 m (1.5 ft)

is slightly below the beam, therefore the shadow effect is lessened.
190 4 Cold Climate - 22 M Facility

Figures 86, 87, and 88 indicate the ceiling jet temperatures recorded at similar depths below the ceiling

for the three radial positions from fire center. From these figures, a rough estimate of the initial velocity can be made. Figure 87 is perhaps the best representation of temperature profiles along the

ceiling to determine the time-of-flight from the 9. 1 m to the 15.2 m thermocouple positions. The

change in temperatures at the depth of 0.46 m below the ceiling indicate an initial velocity of

approximately 0.5 m/s. Similarly, the velocities at lower positions at 0.61 m, 0.76 m, and 0.91 m

below the ceiling are estimated to be nearly 0.5 m/s. These measurements show modest agreement

with the measured ceiling jet velocity at 12.2 m using the hot wire anemometer. However, because the

temperature data were recorded at a rate of 0.25 Hz to 0.2 Hz, the time resolution for these data points

is no worse than 4 s.

Test 20 produced similar temperature results as shown in Figures 89, 90, and 91. The shadowing

effect of the beam in front of the 12.2 m measurement location can also be seen in these figures. The

initial velocities based on temperature measurements were approximately 0.5 m/s, 0.7 m/s, and 0.8 m/s

for the depths of 0.46 m, 0.61 m, and 0.76 m respectively.

Heat Flux Measurements

Heat flux was measured using three heat flux meters located as described earlier. Minimum detector

sensitivity was 0.25 kW/m^. Table 51 lists the average heat flux measured by Rl as a function of

detector position from the center of the pan. Heat flux meter Rl was located near the floor and was not emersed in the hot gas layer during the fire tests. The heat flux measured by this meter was primarily

radiative flux from the flame. Figure 92 presents the heat flux for Rl for tests 14, 15, 17, 20, and 21

where the position of Rl was kept approximately constant. The radiative flux at this position seems to scale linearly with the heat release rate. It should be pointed out that the heat release rate for test 21 was estimated based on fuel surface area.

The radiative flux produced by the JP-8 fire of test 17 is equivalent to the radiative flux produced by

the JP-5 fire of test 20. Both tests were 3.0 m by 3.0 m pan fires with nearly the same heat release

rate. As with the detector tests, this result indicates that the radiative flux produced by these fuels is equivalent.

The heat flux measured by the radiometers located 0.3 m and 6.1 m below the ceiling at 12.2 m east from fire center are presented in Table 52. Since these meters were emersed in the hot gas layer for

most of each test, the heat flux that is measured is a combination of radiation from the smoke layer and

the flame and convective heat flux from the hot gas layer. An indication of what proportion each

transfer mechanism contributes to the measurements can be obtained by calculating the radiation flux

from the smoke layer. This calculation is based on the assumption that the smoke layer is a black body

and the radiative flux from the flame is a point source with a radiative fraction of 0.35. The radiation

flux from the layer was calculated from

I a

where R is the power per unit area received at the detector from the layer, T, is the layer temperature at the heat flux meter and T^ is the ambient temperature of the heat flux meter. The radiation from the

flame was calculated assuming that the emitting region was a point source located at pan center and that
4 Cold Climate - 22 M Facility 191

the smoke layer covering the meter did not absorb any of the radiation. It was assumed that 35 % of the

heat release rate of the fire was converted into radiation.

Referring to Table 52, the expected contributions to the heat flux from the calculated flame and layer

are generally about half the measured value. The heat flux measured by these ceiling mounted devices

is probably due mostly to convective heating. This assumption is substantiated by analyzing the timing

of the flux signals for test 21 as shown in Figure 93.

The heat flux gauge Rl provides a satisfactory time history of the radiation from the flame since it was

located near the floor and out of the smoke layer. The timing for the initial reception of the heat flux is 25 s for Rl, 80 s for R2 and 60 s for R3. If the majority of the radiation received by these heat flux

meters came from the flame, the three detectors would be expected to respond simultaneously in time.

If the layer radiation was the dominant source of heat flux for R2 and R3, these detectors would again

be expected to respond nearly simultaneously. If the dominant contribution to the heat flux came from

convective heating, R3 near the ceiling would be expected to respond first based on the ceiling jet

convectively heating R3 before the layer drops to the position of R2. Since R3 responds before R2, the

conclusion is that the heat flux is convective and that the contribution to the heat flux from radiation at these ceiling locations is at or below the minimum sensitivity of the heat flux gauges. Figure 94

presents the temperature profiles for thermocouples E4 located near R3, E4b located below R3 and E4d

located near R2. The temperature response of thermocouple E4d lags the temperature response of E4

by about 10 s which nearly equals the 20 s delay observed when comparing R2 to R3. These estimates

include the data sampling uncertainty of approximately 4 s. Since the thermocouple measurements will

correlate with increased convective heat flux at these positions, this observation again suggests that the

heat flux meters near the ceiling are measuring convective heat flux and not radiative heat flux.

Heat Release Rate

Heat release information for the eight sprinkler fires was calculated using time dependent mass loss data provided by the load platform. The four-point load platform used for the sprinkler fires could

easily accommodate the 3.0 m x 3.0 m pan. In addition, measurements of initial and final fuel volumes were made. This method of volume measurement has an estimated uncertainty of +3.8 ^ (± 1 gallon),

based on the error in reading the fuel volume from the containment barrels, and any spillage occurring

during fuel transfer.

The amount of fuel consumed by the fire was determined using both the load platform (direct mass loss

rate) method and volume consumed method. The heat release rate was then determined by multiplying

the measured mass loss of fuel by the heat of combustion of the fuel. Using the volume of fuel

consumed method, an estimate of heat release rate was made by calculating the average mass loss,

using the density of the fuel multiplied by the measured volume, over the duration of the test. This

method of determining heat release rate included the volume consumed over the entire test. Since the

final volume was not measured until the residual fuel in the pan cooled to below its flash point, the total volume of fuel consumed would include any losses due to fuel vaporization and minimal losses during

the extinguishment process. Table 53 shows the heat release rate using both methods of mass loss measurement, burning rates, and steady state time interval.

The mass loss rate using the load platform method is provided for all eight sprinkler fires with the

exception of test 21, which is not available because the 4.6 m x 4.6 m fuel pan was not rigid enough to
192 4 Cold Climate - 22 M Facility

be safely placed on the load platform. For this case, the fuel pan was placed directly on the floor. For each test, a linear curve fit was used to determine burning rate after an approximate steady state condition was reached. The steady state condition was defined as the region on the mass loss curve where the slope was consistently decreasing without major fluctuations.

For each experiment a steady state region was determined and the linear fit extended to the limits of the

steady state interval. It is important to realize that by changing the steady state interval, changes may

occur in the resultant heat release value. The uncertainty of the calculated heat release rates was

determined by evaluating upper and lower limits obtained by using curve fits during various portions of

the mass loss curve. Figure 95 shows the measured mass loss for test 14 (2.5 m diameter pan) and test 17 (3.0 m X 3.0 m pan), the region where steady state was determined, and a linear curve fit of the

steady state region.

The burning rate increased during the early part of the fire until a steady state condition was reached.

The time required to reach this condition varied with pan size with the larger pans generally requiring more time to reach steady state. Figures 96 and 97 show the mass loss curves for the 2.0 m diameter,

2.5 m diameter and 3.0 m x 3.0 m test fires using JP-5 and JP-8 fuels. Figure 98 shows a linear

relationship between heat release rate and pan area. The extrapolated heat release value for a 4.6 m x

4.6 m pan is approximately 33 MW.

As previously explained in the detector fire section, there were difficulties in determining the steady

state heat release rate values for several of the sprinkler experiments. These problems were caused by

fluctuations in the mass loss curves during the early stages of the experiment. Fluctuations occurred

due to instrumental anomalies, non-uniform burning, and burning outside of the pan in some cases. Figure 97 shows the mass loss curve for test 15 (3.0mx3.0m pan). This case represents some of the

unusual behavior seen during the initial stages of the experiment. The portion of the mass loss curve from about 330 s to the end of the test appears to be the region with the most consistent slope,

therefore, this region is considered steady state.

4.3.3 Open Door Experiments

Test 16 and 19 were both 2.5 m diameter JP-5 pan fires designed to test the impact of wind on detector

activation. Both hangar doors on the north and south side of the hangar were fully opened for test 16

while only the north door was fully opened for test 19, as shown in Figure 99. Test 14, also a 2.5 m

diameter JP-5 fire test, was conducted with both doors closed so that differences between open and

closed door tests could be examined.

The steady state heat release rates for the three tests are found in Table 53. These values ranged from

a high of 9 MW for test 19 to a low of 7 MW for test 16. The mass loss curve for test 16 was somewhat irregular compared with the mass loss data for tests 14 and 19 as shown in Figure 96. The 7

MW heat release rate for test 16 was based on a linear fit of the mass loss curve for the steady state region between 180 s and 280 s. Looking at the total fuel burned during the first 300 s of the test 16,

the average heat release rate may have been as low as 5 MW. The irregular portions of the mass loss curve may have been the result of the wind blowing through the hangar and thus affecting the mass

readings.
4 Cold Climate - 22 m Facility 193

Table 49. Temperature data for 22 m high facility sprinkler fire tests Test Information Temperamre Data (°C ±2)

Test Pan Size

m

amb Steady State Heat Release

Rate, MW

Nl SI Wl El Max.

Value

Rise Above

T,amb

14a 2.5 dia. 12 7.9 91 90 93 90 87 93 81

15 3.0x3.0 12 15.7 173 169 173 154 168 173 161

16 2.5 dia. 57 63 55 58 62 63 55

17 3.0x3.0 11 14.3 174 175 178 154 169 178 167

18 2.0 dia. 10 4.9 66 66 63 63 62 66 56

19" 2.5 dia. 13 9.1 65 61 70 68 65 70 57

20 3.0x3.0 14 14.6 165 165 166 163 164 166 152

21 4.6x4.6 14 33<^ 277 278 249 464 210 277 263

^ Both hangar doors fully open

'' North hangar door fully open

•^ Heat release value extrapolated from previous test data

Table 50. Hot gas transport times along east direction of ceiling

Test Num. Pan Size

m

HRR

MW

Transport Times (s ±4*)

El E3 E5 E7

Test 14" 2.5 dia. 7.9 30 44 49 77

Test 15 3.0x3.0 15.7 39 43 57 80

Test 16 2.5 dia. 35 44 49 63

Test 17^ 3.0x3.0 14.3 22 42 38 62

Test 18 2.0 dia. 4.9 46 66 66 91

Test 19^ 2.5 dia. 9.1 46 58 54 78

Test 20 3.0x3.0 14.6 30 44 45 66

Test 21 4.6x4.6 33'' 31 39 48 62

indicates the average time interval between successive data scans

^ JP-8 aviation fuel used

" Both hangar doors fully open

" North hangar door fully open

^ Heat release rate estimated from previous data
194 4 Cold Climate - 22 M Facility

Table 51. Average heat flux measurements for detector fires

Test

Number

Pan Size

m Fuel

Heat Release

Rate

MW

Location with Respect to Pan

Center, m(± 0.1)

Distance Height

Heat Flux, Rl

kW/m^(±0.25)

14 2.5 Dia. JP-5 7.9 7.1 1.1 3.5

15 3.0x3.0 JP-5 15.7 7.6 1.1 5.0

17 3.0x3.0 JP-8 14.3 7.2 1.1 5.5

18 2.0 Dia. JP-5 4.9 4.2 1.1 7.0

20 3.0x3.0 JP-5 14.6 7.2 1.1 5.5

21 4.6x4.6 JP-5 33=' 7.2 1.1 9.0

Estimated heat release rate based on previous data

Table 52. Average measured heat flux at R3 & R2 including calculated values.

Heat R3 R2 R3 R2

Layer

R3

Flame

Radiation

Flame

Radiation

kW/m^

Release Measured Measured

kW/m^

±0.25

Layer • Test Number

Rate

MW

kW/m"

±0.25

Radiation

kW/m^

Radiation

kW/m kW/m

14 7.9 1.5 1.0 0.40 0.39 0.27 0.35

::::::::.:::::::::::j:g:::::::::::::::::::::: mm^f^j 2.5"^'"

1.5 0.77 0.68 0.54 0.69

17 14.3 2.5 1.2 0.73 0.64 0.50 0.63

.-.:.-...-...-..,..18. ........,„„ 4.9 ......:..:.,....1.J..:........::.,...:.. .:.:.:.:.:.:.:.:..QJ.:.:.:...:.:.:.:.:.. :.:.:.:.::::.:J.M:.:.:.:.:.:.:.:...: 0.24 0.17 .:.::-::-..,.....;0,.22,.,,„,,..,. 20 14.6 3.0 2.0 0.76 0.69 0.51 0.64

21 33 6.0 4.0 2.47 2.02 1.14 1.45
4 Cold Climate - 22 m Facility 195

Table 53. Heat release information for sprinkler fires

Test

Number

Pan Size

::TM::::x::,,:,.

Fuel Eff. Res. Bum Rate Bum Rate HT?P JclKK HPP rlKK SS Range

Pan Dia. Volume

H ±3.8

(vol.)

kg/m^s

±0.001

(load)

kg/mh

(vol.) (load)

m MW MW s ±0.001 ±1 ±P ±5

14 2.5 dia. JP-5 2.5 143.8 0.037 0.037 8 8 120 - 420

15 3.0x3.0 JP-5 3.39 283.9 0.039 0.041 15 16 330 - 600

16" 2.5 dia. JP-5 2.5 109.8 0.047 0.033 10 7 180 - 270

17 3.0x3.0 JP-8 3.39 325.5 0.044 0.037 17 14 270 - 540

18 2.0 dia. JP-5 2 113.6 0.043 0.036 6 5 180 - 420

19b 2.5 dia. JP-5 2.5 121.1 0.052 0.043 11 9 120 - 240

20 3.0x3.0 JP-5 3.39 280.1 0.038 0.038 15 15 240 - 540

21 4,6x4.6 JP-5 5.19 n/a n/a n/a n/a 33" n/a

* The uncertainty of this value is based on the quality of the measurement over the steady state time

range reported.

" Open door experiment.

"^ Heat release rate determined by extrapolation of pan area versus HRR for previous test data.

Table 54. Comparison of activation time ranges for 2.5 m diameter test fire with open and closed

door configurations.

Test Information Detector Activation Time Range (s)

Test

Number

S7 °r Hpat Photoelectric

Smoke Detectors^

riangar ju'oor

Position 79 °C Sprinklers

J 1 V. ncdi

Detectors

14 Closed 262 - 560 94 - 236 59 - 105

16 North & South

Fully Open

no activations 130 - 174" 50-83

19 North Only

Fully Open

no activations 151-330 45- 115

* Includes all detector locations.

" No activations outside of 3.1 m from fire center.
196 4 Cold Climate - 22 m Facility

40

30 -

oo

0) I 20

0)a.E

h10

-e— E3Jd-9.1 meast

-^- E4Jd- 12.2 meast

-a— E5Jd- 15.2 meast

Depth Below Ceiling = 0.76 m

1 1 1 1 r "T 1 T- "T 1 1

1 r

40

30 -

Oo

0) § 20

<DQlE

(U l15 30 45 60 75 90 105 120

10 -

-e— E4Je- 12.2 meast

-^ - E5Je - 15.2 m east

Depth Below Ceiling = 0.9 m

~1 ' ^ 15 30 45 60

Time (s)

75 90 105 120

Figure 88. Ceiling jet temperature profiles at a depth of 0.76 m and 0.9 m below the ceiling

for the 2.0 m diameter test fire.
4 Cold Climate - 22 m Facility 197

80

60 -

oo

0) § 40

0)Q.E

20

-e— E3Ja-9.1 meast

-r - E4Ja- 12.2 meast

-D— E5Ja - 15.2 m east

Depth Below Ceiling = 0.15 m

15 30 45 60 75 90

80

60 -

0)

•i 40 o

a.E

20

-s— E4- 12.2 meast

-r - E5- 15.2 meast

Depth Below Ceiling = 0.3 m

105 120

15 30 45 60

Time (s)

75 90 105 120

Figure 89. Ceiling jet temperature profiles at a depth of 0. 1 5 m and 0.3 m below the ceiling

for the 3 .0 m X 3 .0 m test fire (test 20).
198 4 Cold Climate - 22 m Facility

80

60

oo

0) I 40

(DQ.E

20

80

-e^ E3Jb-9.1 meast

-r - E4Jb- 12.2 meast -a— E5Jb- 15.2 meast

Depth Below Ceiling = 0.46 m

15 30 45 60 75 90 105 120

-©— E3Jc- 9.1 m east

-^ - E4Jc- 12.2 meast

-a— E5Jc- 15.2 meast

Depth Below Ceiling = 0.61 m

120

Figure 90. Ceiling jet temperature profiles at a depth of 0.46 m and 0.61 m below the ceiling

for the 3.0 m X 3.0 m test fire.
4 Cold Climate - 22 m Facility 199

80

60

o

I 40

a.E

(U

20

-e— E3Jd-9.1 meast

-r - E4Jcl- 12.2 meast

-o— E5Jd- 15.2 meast

Depth Below Ceiling = 0.76 m

1 1

1

1 1

1

1 1

1 r ~1 II I II I 1I I T" 15 30 45 60 75 90 105 120

80

60

Oo

0) I 40 k-Q.Eo

I20

-e— E4Je- 12.2 meast

-^ - E5Je - 15.2 m east

Depth Below Ceiling = 0.9 m

~i I

I

I f 15 30 45 60

Time (s)

~\—' ^ 75 90

-\ 1

1

1 r 105 120

Figure 91. Ceiling jet temperature profiles at a depth of 0.76 m and 0.9 m below the ceiling

for the 3.0 m X 3.0 m test fire.
200 4 Cold Climate - 22 m Facility

10

8

-

.r- 6

X

>

1 -

A Radiometer R1

Located (7.1 - 7.6) m from Pan Center, 1.1 m High

Linear Regression

10

n I I I -j 1 1 1 1 [—1

1 1 1 1- -1 \

1 r 15 20 25

Heat Release Rate (MW)

30 35

Figure 92. Average measured heat flux for sprinkler fires from radiometer (Rl) position.
4 Cold Climate - 22 m Facility 201

12.5

10.0

X

3

(0 X

180 240

Time (s)

420

Figure 93. Heat flux profiles for 4.6 m x 4.6 m test fire.
202 4 Cold Climate - 22 m Facility

220

200

180 -

160 -

140 -

120

oo

0)

a3E 100

80

60 -

40 -

20 -

B— E4 - 12.2 m east, 0.3 m below ceiling r - E4b - 12.2 m east, 0.4 m below ceiling i^— E4d - 12.2 m east, 3.5 m below ceiling

-1 1

I |—

60

-\ 1 r T 1 r n 1 r 120 180

Time (s)

240 300

Figure 94. Temperature profiles in the vicinity of heat flux gauges for 4.6 m x 4.6 m test fire.
4 Cold Climate - 22 m Facility 203

450 -

425 -

400 -

375 -

350 -

325

-60

1000

975 -

950 - 3 925

900 -

875 -

850

825

800

-60

Burn Rate = 0.037 kJ/m s HRR = 7.9 MW

Test 14, 2.5 m Dia. Pan, JP-5 Mass Loss (kg) Linear Fit of Steady State Region

(120 to 420) s

1

'

1

^

1

' 1

60 120 180

I

' I 240 300

Time (s) (A)

360 420 480 540 600

Burn Rate = 0.037 kJ/m s ^HRR=14.3i\/lW

Test 17, 3.0 m X 3.0 m Pan, JP-8 Mass Loss (kg) Linear Fit of Steady State Region

(270 to 540) s

60 120 180

"~i—'—r~

240 300

Time (s) (B)

T T

360 420 480 540 600

Figure 95. Test 14 mass loss curve with linear fit of steady state region (A).

Test 17 mass loss curve with linear fit of steady state region (B).
204 4 Cold Climate - 22 m Facility

500

480

460

440

420 -

400

380 A

o) 360

(0w

340

320

300

280

260 -

240

220

200

Test 18, 2.0 m Dia. Pan, JP-5

Test 14, 2.5 m Dia. Pan, JP-5

Test 16, 2.5 m Dia. Pan, JP-5, Both Hangar Doors Open

Test 19, 2.5 m Dia. Pan, JP-5,

Nortii Hangar Door Open Only

120 —

I

' ^ 240

Time (s)

1

360 480 600

Figure 96. Mass loss curves for 2.0 m diameter and 2.5 m diameter test fires including open

door experiments (tests 16 and 19).
4 Cold Climate - 22 m Facility 205

1000

980 -

960

940

920

900

^ 880

<n

V)

(0 860

840

820 -

800

780

760 -

Test 15, 3.0 m X 3.0 m Pan, JP-5

Test 17, 3.0 m X 3.0 m Pan, JP-8

120 240

Time (s)

360 480 600

Figure 97. Mass loss curves for 3.0 m x 3.0 m test fires using JP-5 and JP-8 fuels.
206 4 Cold Climate - 22 m Facility

0)(0 on

(0

X

oo

1

— Y

1

— 11

1

I

I

1

CO

c

J

20 -

15 - T/

o

,

1

1

,

,

5 -

- Steady State Heat Release Rate HRR = 1.581(Pan Area, m^) + 0.16 D Extrapolated HRR for 4.6 m x 4.6 m Test Fire

n J u " 1 1 1 1 1

1 1 1 1 11 1 ,

1 1> . . . 10 15 20

Pan Area (m

Figure 98. Pan area versus heat release rates for sprinkler fires.
4 Cold Climate - 22 m Facility 207

Drawing not to scale

All dimensions In meters

73.8

WS4 (outside) 24.0 m

above ground, all tests

South Hangar Door Opening

Test 16 : fully open

Test 19 : closed

WS3-Test 16

WS2-Test 16

Draft Curtain 11.6 WS1-Test16

North

2.5 dia. pan

R1, 4.1 from pan ctr

WS2-Test 19

WS3-Test

North Hangar Door Opening

Test 16 : fully open

Test 19 : fully open

45.7

14.8

Figure 99. Instrumentation configuration for open door experiments in 22 m high facility.
208 4 Cold Climate - 22 m Facility

W

c

4 -

1 -

Test 16, 2.5 m Diameter Pan, JP-5 Fuel, North and South Hangar Doors Fully Open

Wind Speed Transducer #1, 0.8 m High

7.0 m from Pan Center (south)

Wind Speed Transducer #2, 2.9 m High

11 .6 m from Pan Center (south)

Wind Speed Transducer #3, 2.9 m High

16.1 m from Pan Center (south)

60

1 1 r "T 1 r 120 180 240 300 360

Time (s)

Figure 100. Wind speed measurements for test 16. North and south hangar doors open fully.
4 Cold Climate - 22 m Facility 209

15

10

E

a>

(DQ. CO

X>c

5 -

Test 16, External Wind Speed

Test 16, External Wind Direction North

- 150

West

n 1 r -1 1 r T

60 120 180 240

Time (s)

~i—'—

300

180

120

90

3

o

(AE

oi_

0)

0)

v_O)

(U 2,c

o

•s

T3C

- 60

30

360

Figure 101. External wind speed and direction measurement for test 16. Sensor was located on the roof at the south end of the hangar 24 m above floor level.
210 4 Cold Climate - 22 m Facility

80

70

60 -

50 -

p

•i 40

0)Q.E

0)

30

20 -

10 -

Test 16, 2.5 m Diameter Pan

Both Hangar Doors Open Fully Thermocouple N1 , 3.0 m North

-^ - Thermocouple N2, 6.1 m North -o— Thermocouple SI, 3.0 m South --- Thermocouple S3, 6.1 m South

n 1 r1

'—'—'

r~ 60 60

~i 1

1

1—~T 1

1

1 1 1

1 1 1 11

1 1 r- 120 180 240 300 360

Time (s)

Figure 102. Temperature profiles at 0.3 m below ceiling for test 16.
4 Cold Climate - 22 M Facility 211

50

45 -

40

35

E 30

a0)

0)Q. w

T3c

25 -

20 -

15

10

5 -

Test 19, External Wind Speed

Test 19, External Wind Direction North

West

-I 1 11

1 1 1

1

1

1 1

1 r- 60 120 180

Time (s)

-1 1

1 1 1 r 240 300

- 150

- 120

180

3o

E

V)(O

90 ^

c

g

b

C

- 60

- 30

360

Figure 103. External wind speed and direction measurement for test 19.
212 4 Cold Climate - 22 m Facility

12

11

10 -

7 - E

a

0) D w

T3C

5 -

1 -

Wind Speed Transducer #1 , 0.8 m High

6.0 m from Pan Center Wind Speed Transducer #2, 0.8 m High

5.7 m from Pan Center, 3.4 m East Wind Speed Transducer #3, 0.8 m High

5.7 m from Pan Center, 3.4 m West

Test 19, 2.5 m Diameter Pan, JP-5 Fuel, North Hangar Door Fully Open

~i 1 I

I

p I I

I I I r -1 1 1

1 1 1 r 60

r

120 180 240

Time (s)

300 360

Figure 104. Wind speed measurements for test 19. North hangar door fully open.
4 Cold Climate - 22 m Facility 213

80

70

60

50

Oo

2

Q.£

(D

40

30 -

20 -

10

Test 19, 2.5 m Diameter Pan

North Hangar Door Open Fully Thermocouple N1, 3.0 m North Thermocouple N2, 6.1 m North Thermocouple SI, 3.0 m South

Thermocouple S3, 6.1 m South

-60 60 —I , , 1

I 120 180

Time (s)

I 240 300 360

Figure 105. Temperature profiles at 0.3 m below ceiling for test 19.
214 4 Cold Climate - 22 m Facility

i

100

90

80

70

60 - O

0)

i_

\—0)Q.E

0)

ra 50

40 -

30 -

20

10

Center Temperature,

0.3 m Below Ceiling Test 14, 2,5 m Diameter Pan

Hangar Door Closed

Test 16, 2.5 m Diameter Pan, Both Hangar Doors Open Fully Test 19, 2.5 m Diameter Pan,

North Hangar Door Open Fully

60 120

-^—'—r~

180

Time (s)

240 300 360

Figure 1 06. Comparison of open door and closed door experiments and the effect on center

temperatures measured at 0.3 m below ceiling.
4 Cold Climate - 22 M Facility 215

Wind speed profiles are shown in Figure 100 for test 16. The location of the wind speed sensors are given in Figure 99. For test 16, wind sensors 2 and 3 were located at a height of 2.9 m above the floor

while the wind sensor 1 was located 0.8 m above the floor. The different heights were chosen based on CFD modeling which suggested that for wind blowing perpendicular to the open hangar doors, the

wind speed would be higher near the floor. This was realized for test 16 and as a result, wind sensor 2 was reduced in height to 0.8 m above the floor for test 19. At about 130 s, the load cell data for test 16 shows an increase of mass, but this measurement may be affected by the wind blowing through the

hangar which increases from about 1 km/hr to 3 km/hr to 6 km/hr at about the same time. If the

increasing wind caused an upward lift on the load cell, a fictitious increase in mass could be measured.

Analyzing test 16 first, at the start of the fire the flame was initially upright and then leaned to the north

from 15 ° to 30 " between 30 s and 120 s into the test. Wind speeds measured 5.7 m from the edge of

the pan and 0.8 m above the floor were less than 2 km/hr for the first 120 s of the test. At 60 s into the

test, there was some fuel burning off the north side of the pan. A rotation in the north side of the flame

developed at about 100 s which persisted for about 40 s. At 120 s, the flame began leaning further to the north reaching a lean of 60 ° north by 160 s. The wind speed during this time had increased at all three monitoring locations with the 5.7 m location reaching 6 km/hr. The flame lean continued to maintain a 45 "to 60 ° lean for the next 100 s. By 260 s, the flame was leaning 75 " to the north and

the wind speed at the 5.7 m location had increased 7 km/hr. The 75 ° lean to the north persisted until

the end of the experiment.

One notable difference between this experiment and the closed door test 14 was the amount of smoke

introduced into the ambient air near the floor. By 240 s into the test, the air was becoming very

smokey close to the floor for this test whereas the same area for test 14 remained almost free of smoke.

The difference in smoke density at this height may be verified qualitatively using the flame height camera video and observing the clarity of the image of the east wall. For test 14, the east wall remains

clear for the entire test with the leading edge of the smoke layer apparent on the wall. For test 16, the

leading edge of the smoke layer is still apparent but the clarity of the wall image below the smoke layer

is not as good.

Outside wind speed and wind direction for this test are shown in Figure 101. The measurement was made above the roof at the south end of the hangar. Since the hangar doors were oriented in the north

- south direction, the wind was blowing at an angle to the doors which increased from 30 ° west of

south to 50 " west of south by the end of the test.

Ceiling temperatures for this test followed the flame lean analysis fairly closely. Early in the test when

the flame lean was 45 degrees or less, temperatures at thermocouple positions Nl and N2 reached

about 65 °C as shown in Figure 102. At 160 s when the flame lean increased to 60 ° north, the

maximum ceiling temperature decreased to about 53 °C. The temperature then began to increase

reaching 65 °C at about 230 s into the test but as the flame leaned over to about 75 ° north, the

temperature near the ceiling fell to below 55 °C for the duration of the test. The Nl and N2

thermocouples consistently read between 5 °C and 10°C higher than the SI and S3 thermocouples

which is consistent with the northward lean of the flame.

Heat detectors with activation temperatures of 57 °C (135 °F) activated in the north, east and west

directions 3.0 m from the fire center and also in the north direction 6.1 m from the fire center as shown

in Table 52. No heat detectors activated in the south direction which is consistent with the observed
216 4 Cold Climate - 22 M Facility

flame lean to the north and the lower temperatures measured by the south thermocouples. The heat

detector located 3.0 m to the east of fire center activated 34 s earlier than the heat detector located 3.0

m to the west of fire center which is consistent with the higher temperature readings by thermocouple

El compared with Wl and is also consistent with the wind blowing 30 ° west of south.

No sprinklers were activated during the test since the minimum activation temperature of 79 °C was

not reached. This is in contrast to test 14, a closed door test, where all but two of the 79 °C sprinklers were activated within 3.1 m of fire center. Table 54 shows the activation time ranges for 79 °C

sprinklers in both open and closed door 2.5 m diameter test fires.

Smoke detector activation occurred between 46 s and 58 s for all smoke detectors located within 9.1 m

of fire center. Outside the draft curtain, the smoke detector to the north at 9.1 m from fire center

activated 8 s before the smoke detector located to the south at 9. 1 m. These activation times were

substantially longer than the activation times in the east - west direction where smoke detectors 12.2 m

from fire center were activating 16 s and 21s earlier than the north - south detector at 9. 1 m. The later activation times in the north - south directions indicate that the draft curtain was able to contain the

smoke even with the wind blowing through the hangar.

Test 19 was conducted with only the north door fully open. While the south door was closed, there was substantial leakage of air around the east and west corners of the door which would provide some

potential for the movement of air out of the south side of the building. Outside wind velocities for this

test averaged 39 km/hr with the wind direction varying from 50 " west of south to 80 ° west of south as shown in Figure 103.

The flame exhibited a 15 ° lean to the south at the start of the test which increased to 45 ° to the south

by 50 s. At 70 s, the flame lean had returned to 15 " to the south and completely disappeared by 80 s. At this time some fuel was observed to be burning off the side of the pan. By 1 10 s, the flame again

leaned 15 ° to 30 ° to the south, became more upright with about a 15 " lean at 170 s, and then returned

to the 15 ° to 30 ° south lean at 180 s. At 230 s, the flame lean increased to 45 ° and persisted

throughout the rest of the test.

At 240 s the area near the floor began to become extremely smokey. The smoke near the ceiling was

observed to be flowing toward the south part of the building. The smoke would then deflect down and

flow north back toward the fire near the floor. This mixing of smoke into the lower layer near the

floor caused an evacuation of the hangar by people not having breathing apparatus at 330 s into the

test. Neither test 14 where the air stayed relatively clear near the floor for the entire test nor test 16

where smoke did mix into the air near the floor generated the smokey condition near the floor that was

realized for test 19.

The location of the wind speed direction sensors for test 19 are presented in Figure 99. Since only one

hangar door was open and since the wind direction was at an angle to the door opening, the wind

sensors orientation was changed from the one used for test 16 in an effort to pick up any east - west

asymmetry in the wind speed near the fire. Even though the outside wind speed for test 19 was 3.5

times that measured in test 16, the wind speed within the hangar was equal to or less than the wind

speeds measured in test 16 with the exception of a single gust at 250 s which reached a peak speed of

18 km/hr at wind sensor 3. The wind speeds measured by all three sensors is shown in Figure 104.

This gust coincided with the flame lean increasing to 45 ° to the south. Wind sensor 3, which was
4 Cold Climate - 22 M Facility 217

located on the east side of the fire consistently gave higher wind speeds which would be expected with

a wind blowing from the southwest since this sensor would be least shielded by the west building wall.

Temperature profiles for this test are given in Figure 105. Maximum temperatures at the ceiling

reached as high as 80 °C for the thermocouples located at SI and S3 which is consistent with the south

lean observed by the flame. The ceiling temperatures are higher than the temperatures measured in test 16 but lower than those of test 14. Ceiling temperatures for test 14, where the doors were closed,

reached as high as 95 °C as shown in Figure 106. Temperatures were higher in the south and west

directions for test 19. The west direction is curious since the wind was blowing from the west, the

shadowing of the west wall would be expected to produce higher temperatures to the east as seen in test 16. It is possible that the closed door at the south end of the hangar generated a swirling wind pattern near the ceiling which caused the air flow to be toward the west at these elevations.

All the heat detectors activated out to 6. 1 m from fire center with the heat detectors toward the south

and west activating first, consistent with the thermocouple temperatures. Additional heat detectors

activated 9.1m and 12.2 m to the west of fire center. There were no heat detector activations to the

north beyond the draft curtain. Table 54 shows the activation time ranges for heat detectors within 6.

m of fire center for closed and open door test fires.

No sprinklers were activated for this test as ceiling temperatures did not reach the necessary threshold

of 79 °C.

All smoke detectors activated within 18.3 m of fire center as seen in Table 54. The earliest activation

times occurred to the south which is consistent with the early rise of the thermocouples located at SI

and S3. The early activation of smoke detectors to the west at 12.2 m, 15.2 m and 18.3 m from fire center compared with smoke detectors located to the east at the same distances is consistent with the

higher thermocouple readings to the west. The two smoke detectors in the north - south direction

located 9.1 m from fire center outside the draft curtain activated within 13 s of each other. The north

smoke detector activated first which suggests that the general flow pattern is out of the hangar near the

ceiling and into the hangar near the floor.
218 4 Cold Climate - 22 M Facility

4.4 Response of Detection and Sprinkler Activation Systems to Fires

4.4.1 Sprinkler Activation Times

The spacing and installation of the automatic sprinklers are described earlier in section 4. Figure 56

shows the location of the automatic sprinklers installed for these experiments. In the 22 m high facility,

the sprinkler response analysis included number and type of sprinklers activated, response times, effect of draft curtains, threshold fire sizes for detector and sprinkler response, effects of ceiling

configuration, effects of thermal element, the conductive heat transfer effects of wet-pipe versus drypipe sprinkler configurations, and the effects of ceiling height.

None of the sprinklers responded in any of the experiments where the fire size was less than 3 MW.

For fire sizes greater than 3 MW, tests 16, 18, and 19 did not activate any automatic sprinklers. Tests 16 and 19 were 2.5 m diameter pan fires with heat release rates of 7.0 MW and 9.1 MW respectively.

Both of these experiments were conducted with the hangar doors open. Tests 18 was a 2.0 m diameter

pan fire conducted with the doors closed which produced a heat release rate of 4.9 MW.

In the remaining closed-door experiments, five fires with heat release rates of 7.9 MW and greater

activated sprinklers in the 22 m hangar. Table 55 shows the response times of all the sprinklers which

activated in those five experiments as well as indicating which tests were performed using JP-5 or JP-8

fuels. Also, all five tests were performed with the hangar doors closed and with draft curtains in place.

The smallest size fire to activate any automatic sprinklers was test 14 which used the 2.5 m diameter

pan fire with a heat release rate of approximately 7.9 MW. Tests 15, 17 and 20, which were the 3.0 m

X 3.0 m pan fires, had heat release rates ranging from approximately 14.3 MW to 15.7 MW. Test 21

used the 4.6 m X 4.6 m pan fire with a heat release rate of approximately 33 MW.

Effects of Fire Size

The experimental fires were designed to determine the threshold fire sizes needed to activate a variety

of sprinklers, with the primary focus on the 79 °C and 141 °C sprinklers. The threshold fire size

needed to activate the 79 °C sprinklers in the 22 m hangar was the 2.5 m diameter pan fire which

produced a heat release rate of approximately 7.9 MW. The threshold fire size needed to activate the

93 °C and 141 °C sprinklers in the 22 m hangar was the 3.0 m x 3.0 m pan fire which produced heat

release rates ranging from approximately 14.3 MW to 15.7 MW. The 4.6 m x 4.6 m pan fire (test 21)

which produced a heat release rate of approximately 33 MW was the largest fire conducted in the 22 m

hangar. Although Table 55 indicates that not all of the sprinklers activated in test 21, it is important to note that the test was terminated at 294 s because ceiling temperatures exceeded the predetermined

safety level.

Fire size affected both the number of sprinklers activated and the response times. Table 56 shows the

number of sprinklers activated for each of the experiments. The effect of fire size on sprinkler

response time can be examined by comparing the response times of the same sprinkler heads to various

fire sizes. Figure 108 graphically shows the effect of fire size on sprinkler response times for a variety

of sprinkler heads. Fire size also affected sprinkler activation distance from the plume center. For

example, in test 14, no sprinklers activated beyond 3.1 m from plume centerline. Whereas in test 21,

sprinkler activation occurred as far away as 15.2 m from plume centerline.
4 Cold Climate - 22 m Facility 219

Table 55. Sprinkler activation times, seconds; n=no activation; a=activation, time unknown;

*=no sprinklers installed

Test

# Sprinkler Location

Sprintcler Type (see Figure 56)

A B C D E F G,H,I

#14

2.5 m

7.9 MW

center n 560 n n n 366 n,n,n 3mrad. (N,S,E,W) n,n,n,a a,361,546,

499

n,n,n,a n,n,n,n n,n,n,n n,262,485,

480

*

6.1mrad. (N,S,E,W) n,n,n,n n,n,n,n n,n,n,n n,n,n,n * + *

9.1mrad. (E,W) n,n a,n * + *

12.2 mrad. (E,W) n,n n,n * + * *

15.2mrad. (E,W) n,n n,n * * * * *

#15

3x3m

15.7 MW

center n 123 608 473 337 119 128,221,n

3 m rad. (N,S,E,W) 384,324,444,

n

119,119,132, 142501,473,640,n 440,417,501,

529

389,384,440,

444

a,119,114,

375

*

6.1mrad. (N,S,E,W) a,n,a,n 169,151,281, 174n,n,n,n n,n,a,n

* * *

9.1mrad. (E,W) n,n a,239 * * + * *

12.2 mrad. (E,W) n,n 309,291 + * * * *

15.2 m rad. (E,W) n,n 389,314 t * * * *

#17

3x3m

14.3 MW

center 392 112 575 495 n 112 121,323,n

3 m rad. (N,S,E,W) 388,378,n,

402

100,n,12I,

121

a,495,584,575 425,406,n,519 420,359,420,

519

a,92,117,112

6.1mrad. (N,S,E,W) n,n,n,n a,137,n,a n,n,n,n n,n,n,n * * *

9.1mrad. (E,W) n,n n,a

* * *

12.2 m rad.(E,W) n,n 355,a * * * * *

15.2 m rad. (E,W) n,n a,355 * * * * *

#20

3x3m

14.6 MW

center 517 119 600 512 455 115 142,n,n

3 m rad. (N,S,E,W) 447,382,493, 503

115,101,124, 115

n,n,n,n 484,n,53 1,521 414,391,n,503 n,n, 124,1 15 *

6.1 m rad. (N,S,E,W) n,n,n,n n,147,165,n n,n,n,n n,n,n,n * * *

9.1 mrad. (E,W) n,n 262,n * *

12.2 m rad. (E,W) n,n 405,n *

15.2 m rad. (E,W) n,n n,n

+

#21

4.6 m

33 MW

center n 91 127 n n 91 100,n,136

3 m rad. (N,S,E,W) 114,a,118, 118

87,87,91,91 127,a,a,154 127,a,132,132 114,109,114, 114

87,87,87,91

6.1 m rad. (N,S,E,W) a,a,136,140 a,91,95,100 a,n,n,n a,n,168,n *

9.1mrad. (E,W) 190,n 190,n * *

12.2 m rad. (E,W) 222,n 123,123 * *

15.2 m rad. (E,W) a,n a,132 * 4 *
220 4 Cold Climate - 22 m Facility

Table 56. Comparison of fire size to number of sprinklers activated

Test Number HRR(MW) No. of Sprinklers Activated

14

17

7.9

14.3 29

20 14.6 27

15 15.7 37

21 33 37

Effects of Ceiling Configuration

The roof of the 22 m hangar consisted of a series of open steel trusses which formed arches spanning

the width of the hangar bay. Although the trusses would not be expected to have an effect on the

response times, since they would not obstruct the movement of heated gases from a fire, the overall

shape of the curved roof was evaluated for its effect on sprinkler response. The effects of ceiling curvature were analyzed by comparing the response times of the sprinklers along the north/ south axis

to those along the east/west axis. This comparison was limited to the sprinklers at 3. 1 m and 6.1m

from plume centerline. The sprinklers mounted along the north/south axis were located along the peak

of the curved ceiling, while the sprinklers located along the east/west axis were at slightly lower

elevations due to the curvature of the ceiling. Figure 107 compares the average response times of six

different sprinkler types along the north/south axis versus the east/west axis, at a distance of 3.1 m

from plume centerline. As one might expect, the sprinklers at the highest elevation of the curved roof

activated faster than the same heads at a slightly lower elevation. Over 27 comparisons throughout the

five fire tests which activated sprinklers showed the sprinklers in the north/south direction had faster response times than the sprinklers in the east/west direction.

Effects of Thermal Element

Two factors were analyzed regarding the effects of the thermal element used in the sprinkler head

assembly. The first was the temperature rating of the sprinklers used (i.e., 79 °C, 93 °C, 141 °C, and

182 °C). The primary concern with respect to temperature rating deals with the fire size needed to activate various temperature heads as discussed above. As expected, the 79 °C heads responded faster than the 93 °C heads.

The second factor analyzed was the response time index (RTI), which for this analysis focused on quick

response versus standard response heads. Figure 109 shows a comparison of the 79 °C quick response

versus standard response sprinklers located at plume centerline in tests 15 and 17. This illustrates the

significantly faster response times of the quick response heads.

Effects of Wet- vs. Dry-Pipe Sprinklers

Several 79 °C sprinkler heads were piped in both the wet-pipe and dry-pipe configurations in order to determine if the type of system (i.e., wet or dry) affected sprinkler response time. Table 57 shows the
4 Cold Climate - 22

m Facility 221

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222 4 Cold Climate - 22 m Facility

Table 57. Comparison of average response times of wet-pipe and dry-pipe sprinklers

Test Number 79^ G QR-Wet (s) 79°C QR-Pry (s) % Difference

14 469 N/A N/A

15 128 203 -58.6

17

20

114 107

114 120

6.1

-5.3

21 89 88 1.1

Table 58. Comparison of sprinkler response times for tests conducted in 15 m and 22 m high

facilities Parameters 15 m hangar

Test 6b - 2.5 m pan, JP-5

22 m hangar

Test 14 - 2.5 m pan, JP-5

Heat Release Rate 7.7 MW 7.9 MW

No. of sprinklers activated 18 8

Time of 1st sprinkler response 78 s (79 °C QR) 262 s (79 °C QR)

Time range: sprinkler response 78 -439 s 262 -560 s

Furthest distance of sprinkler

response from plume center

9.1 m 3.1m
4 Cold Climate - 22 m Facility 223

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224 4 Cold Climate - 22 m Facility

360

300

240

I

180

120

60

79 C STD 79 C QR 79 C STD 79 C QR

Test 17

13,3 MW

Testis

15.1 MW

Type of Sprinkler

Figure 109. Response time comparison of 79 °C STD sprinkler to 79 °C QR sprinkler for two 3.0

m X 3.0 m test fires conducted in 22 m hangar.
4 Cold Climate - 22 M Facility 225

average response times for the 79 °C quick response (wet) vs the 79 °C quick response (dry) sprinklers

located 3.1m from plume centerline. This illustrates no significant difference in sprinkler response

times with respect to wet-pipe versus dry-pipe sprinklers. Obviously, there is still a time delay on drypipe or pre-action systems associated with opening the alarm valve and filling the distribution piping

with water.

Effects of Ceiling Height

Given the differences in size, construction and climatic conditions between the 15 m and 22 m hangars,

the effects of ceiling height on sprinkler response cannot be fully analyzed from this data set. Attempts

to compare sprinkler response times between the two sets of experiments must also consider ambient air and fuel temperatures, as well as the volume of the draft curtain spaces. In addition, only similar sized

fires can be compared. Given those limitations. Table 58 shows a comparison of sprinkler response

times for the 2.5 m diameter pan fires in both the 15 m and 22 m hangars.

4.4.2 Response of Projected Beam Smoke Detectors

Fire tests conducted in the 22 m high facility provided information relative to the response of projected

beam smoke detectors as a function of location (i.e., depth below ceiling), sensitivity settings, window

settings, and spacing. The projected beam detectors were installed parallel with the curved portion of

the ceiling at three elevations, 1.9 m (6.2 ft), 4.2 m (13.8 ft), and 10.9 m (35.8 ft) below the peak of

the arched ceiling. One exception was the beam detector set (T7/R7) installed at 1.3 m (4 ft) below the

ceiling perpendicular to the draft curtain.

In all the fire tests performed in the 22 m high facility, detectors located 1.3 m and 1.9 m below the

ceiling peak (i.e., B7, Bl, B2) used an alarm sensitivity of 20% signal loss with an alarm window

setting of 5 s. Detectors located at 4.2 m and 10.9 m below the ceiling peak (i.e., B3, B4, B5, B6)

used an alarm sensitivity of 30% with an alarm window setting of 5 s.

4.4.2.1 Fires less than 3 MW (tests 1-13)

Detector fires were used to determine the response characteristics of the projected beam smoke

detectors. The detector response times for these smaller fires are listed in Table 59.

The alarm times given indicate the length of time needed for the smoke to fill the test bay and reach the

depth of the detector. Figures are included which show each pan size tested and the resulting alarm

time for detectors at various detector depths below the ceiling peak. It is important to note that figures

which include detectors at 1.3 m and 1.9 m below the ceiling (i.e., B7, Bl, B2), have sensitivity

settings of 20% signal loss. Whereas the pairs of detectors at 4.2 m and 10.9 m depth have sensitivity

settings of 30% signal loss. In both configurations, the alarm window setting was 5 s.

For the 0.3 m x 0.3 m test fires alarm times range from an average of 57 s for detector B7, located

1.3 m below the ceiling peak, to an average of 351 s for detector B6, located 10.9 m below the ceiling

peak. Averages for these tests do not include test 9. In test 9, JP-8 fuel was used inthe0.3mx0.3m

pan. The alarm values, in this case, for the lower two detectors located 5.5 m south of center (i.e., B4,

B6) are significantly higher than the corresponding detector located 5.5 m north. This irregularity is
226 4 Cold Climate - 22 m Facility

Table 59. Results of projected beam smoke detector activation to detector fires conducted in 22 m

high facility

Test Information Projected Beam Detector Response Times (s, +5) | Test;;' Pan Size

m

Fuel BP B2'' B3'' 64" B5'' 66" B7^

1 0.3x0.3 JP-5 93 88 111 118 392 377 53

2 0.3x0.3 JP-5 78 78 99 97 362 325 60

3 0.6x0.6 JP-5 38 47 49 57 205 211 36

4 0.6x0.6 JP-5 24 29 36 45 214 244 19

5 0.9x0.9 JP-5 28 31 33 42 154 149 25 m

6 0.9x0.9 JP-5 34 39 39 44 161 171 31

7 1.2x1.2 JP-5 39 39 38 .: „:42,„,_, 106 i25 .....:..3.I ..:.:.:::.::;:: 8 1.2x1.2 JP-5 34 38 35 42 118 122 27

9 0.3x0.3 JP-8 94 149 85 165 126 205 108

10 0.6x0.6 JP-8 47 58 60 60 161 142 47

11 0.6x0.6 JP-8

35 ''

49 45

... ...^.^....._... 125 ......,..._^.... ,..„... ........_ ^...,.....,.

12 0.9x0.9 JP-8 33 43 39 49 103 96 34

13 1.2x 1.2 JP-8 31 41 42 49 85 83 37 :::

^ alarm sensitivity setting, 20%, alarm window, 5; ''alarm sensitivity setting, 30%, alarm window, 5 s

due to excessive plume lean during the early stages of test 9. During this test, external wind speeds were measured at 35 km/hr to 50 km/hr (21 mph to 31 mph) from the south direction. The upper

graph in Figure 1 10 shows the alarm times for all 0.3 m x 0.3 m test fires.

For the 0.6 m X 0.6 m test fires, alarm times were reported between 19 s to 47 s at the highest location

and 125 s to 244 s at the lowest detector depth. In comparison to the 0.3 m x 0.3 m test fires, the

detector located 1.3 m below the ceiling peak responded nearly 25 s faster. Detectors located 1.9 m

below the ceiling peak responded nearly 50 s faster. The lower two detector sets alarmed at an average

value of 52 s for the 4.2 m depth and 182 s for the 10.9 m depth. The alarm values at these two depths

are about one-half compared to the 0.3 m x 0.3 m tests. The lower graph in Figure 113 shows the

alarm times for all 0.6 m x 0.6 m fires.

The detector response times for the 0.9 m x 0.9 m and 1 .2 m x 1 .2 m pans ranged from 30 s to 45 s for

the detectors at 1.3 m, 1.9 m, and 4.2 m below the ceiling peak. Detectors B5 and B6, at the lowest

elevation, responded within an average of 139 s for the 0.9 m x 0.9 m pan and 106 s for the 1.2 m x

1.2 m pan. Figure 111 shows the alarm times for all test fires using the 0.9 m x 0.9 m and 1 .2 m x

1.2 m pans.

The test fires using JP-8 indicate slightly faster response times at the lowest elevation compared to test

fires using JP-5. The upper elevations (i.e., 1.3 m, 1.9 m, and 4.2 m) do not show this increase in

response time. One factor that may explain this is that the external wind speed during tests 9 through

13 was nearly 2.5 times higher than previous tests. The draft curtains may have provided some

protection from air currents affecting the upper areas of the test bay. However, the lower set of

detectors at 10.9 m below the ceiling peak could have been in an area where air currents caused
4 Cold Climate - 22 M Facility 227

increased smoke mixing, therefore, producing alarm times faster than in previous "calm" tests. In

addition, video footage taken during these tests indicate significant plume lean and changes in smoke

movement patterns.

Additional figures are shown that provide information on the relationship between fire size and detector

response times at various elevations in the test bay. Figure 1 12 shows the response of detectors at 1 .3 m and 1.9 m below the ceiling peak. The detectors at these locations had sensitivity settings of 20%

signal loss and a 5 s alarm window. Figure 113 shows the response of detectors at the 4.2 m and 10.9

m elevations. These detectors used a sensitivity setting of 30% signal loss and a 5 s alarm window.

These figures include the results from tests run with both JP-5 and JP-8 fuels.

The differences in response time values reported for the detectors at 1.3 m and 1.9 m versus the

detectors at 4.2 m and 10.9 m may also be attributed to the difference in sensitivity settings. The

detectors using the 20% sensitivity setting are more sensitive to the developing smoke layer. An

analysis of the detector's output signal shows a rapid decrease in strength when sensing the developing

smoke layer, meaning that any change in response time would be negligible if a lower sensitivity setting was chosen (i.e., 30% signal loss). However, those experiments where the smoke layer developed

gradually (i.e., 0.3 m x 0.3 m and 0.6 m x 0.6 m test fires) show a slower decrease in detector signal.

For example, during test 4 (0.6 m x 0.6 m test fire) the detectors at 10.9 m depth below the ceiling

alarmed at 214 s and 244 s. If their sensitivity settings were increased (i.e., 20% signal loss) the

detectors would have responded 20 s to 30 s faster. The detectors at the next higher elevation would

have responded only 5 s to 10 s faster. For the detectors at the highest elevation the difference is less than 3 s.

4.4.2.2 Fires greater than 3 MW (tests 14-21)

For the test fires with heat outputs greater than 3 MW, the response times of the projected beam smoke

detectors are presented in Table 60.

For the 2.0 m diameter test fire the detectors all responded within 97 s. The detector at the highest

elevation responded at 42 s and the detectors at 1.9 m an 4.2 m responded within 16 s later. The

detectors at the 10.9 m elevation responded at 90 s and 97 s. The upper graph in Figure 1 14 shows the

response times for this test.

Of the three tests conducted using the 2.5 m pan, only test 14 was conducted with the hangar doors in the closed position. The first open door test (16) was conducted with both north and south hangar

doors partially open and for the second open door test (19) only the south hangar door was open. The

first experiment using the 2.5 m diameter pan produced projected beam response times from 38 s at the

highest elevation to 87 s at the lowest elevation. The first open door test produced trouble conditions on all but the two detectors located 10.9 m below the ceiling. The trouble condition arises when the

detector experiences a 90% signal loss for a pre-set length of time (i.e., 2 s). Once the trouble

condition occurs the detector may be able to reenter alarm stams if the smoke thins or the object

blocking the beam is removed.

According to video footage and visual accounts, during test 16 the severity of the plume lean caused the

majority of the smoke to collect in the adjacent bay. When the cross-wind decreased, the plume
228 4 Cold Climate - 22 M FAcnjTY

420

360 -

300 -

§ 240 H

<

oI

180

120 -

60

300

240

f 180

JO<

2

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60 -

0.3 m X 0.3 m pan

O Test1,JP-5

Test2,JP-5

A Test 9, JP-8

A

1.3

I \ 1.9 4.2

Distance Below Ceiling (m)

0.6 m X 0.6 nri pan

O Test 3, JP-5

Test 4, JP-5 A Test 10, JP-8 V Test 11, JP-8

A

A

1.3 —I 1

1.9 4.2

Distance Below Ceiling (m)

A

10.9

A

I

V

10.9

Figure 1 10. Projected beam detector response times for 0.3 m x 0.3 m and 0.6 m x 0.6 m

test fires in 22 m high facility.

1
4 Cold Climate - 22 m Facility 229

180

60

30 -

180

150

^ 120

E

re < 90 H

o

O)EF

60

30

0.9 m X 0.9 m pan

O Test 5, JP-5 150 - Teste, JP-5 A Test12, JP-8

120 -

>!£- E

TO < 90 -

O

0)E

A

O

1.3 1.9 4.2

Distance Below Ceiling (m)

1.2 m X 1.2 m pan

O Test?, JP-5 H Test 8, JP-5 A Test 13, JP-8

A

A

1.3 1.9 4.2

Distance Below Ceiling (m)

Q

§

A

A

10.9

o

10.9

Figure 111. Projected beam detector response times for 0.9 m x 0.9 m and 1.2 m x 1.2 m

test fires in 22 m high facility.
230 4 Cold Climate - 22 m Facility

0.0

GO

liiU •

1.3 m Below Ceiling

O Detector B7, JP-5 • Detector 87, JP-8 90 -

v^

CD <

O

0)£

60 - o

o •

30 - o# • •

o

-

1 1 1 1 1 0.5 1.0 1.5

Fire Size (MW)

2.0 2.5

0.5 1.0 1.5

Fire Size (MW)

2.0 2.5

3.0

150 -

1.9 m Below Ceiling Detector 81

Detector 82

JP-5

JP-5 120 - • Detector 81 JP-8

Detector 82 JP-8

E

m

90 - §

•

<

o Q

Q)E

i- 60 -

30 -

• O • • 8

g !

- 1 1 1 1 3.0

Figure 1 12. Projected beam response times for detectors at 1.3 m and 1.9 m elevations with

respect to fire size.
4 Cold Climate - 22 m Facility 231

0.0

420

360

300 -

I 240

<

o% 180 E

120

60 -

o

o

0.0

lOU

4.2 m Below Ceiling 160 - O Detector B3, JP-5

Detector 84, JP-5 140 - • Detector 83, Detector 84,

JP-8

JP-8

.£. 120 - n

E

TO < 100 - o

§

E

i- 80 -

60 -

•

•

40 - o

•

• 8

O

20 -

1 1 1 1 0.5 1.0 1.5

Fire Size (MW)

2.0 2.5

10.9 m Below Ceiling

O Detector 85, JP-5

El Detector 86, JP-5 • Detector 85, JP-8

Detector 86, JP-8

@

0.5 1.0

1

1.5

Fire Size (MW)

2.0 2.5

3.0

3.0

Figure 113. Projected beam smoke detector response times for detectors at 4.2 m and

10.9 m elevations with respect to fire size.
232 4 Cold Climate - 22 M Facility

Table 60. Results of projected beam smoke detector activation to sprinkler fires conducted in 22

m high facility

. ¥ /* T* 'it r» -r^. i TS nrt+ jr /^N. Tesi iniormauon iTojeciea tjeam jueiecior Kesponse limes (^s, j::>; | Test# Pan Size

m

Fuel BP 62" 63" 64" 65" 86" B7''

14 2.5 dia. JP-5 46 46 50 53 87 87 38:.;::i 15 3.0x3.0 JP-5 43 43 49 49 84 85 33

16^ 2.5 dia. JP-5 T T, ,. . ., T 52 . . , 37;. . ., ;,.:;t..,: . T... 17 3.0x3.0 JP-8 32 34 35 35 67 107 27

18 2.0 dia. JP-5 48 55 50 58 97 90 42

19d 2.5 dia. JP-5 47 40 44 42 47 T 39

20 3.0x3.0 JP-5 37-^ •^- •

• ' "•37" "' " m "" ''''"40'^' "- ''V'

""

''m-''-'''' 31

21 4.6x4.6 JP-5 33 45 39 48 75 72 30

Alarm sensitivity setting, 20%, alarm window, 5 seconds

^ Alarm sensitivity setting, 30%, alarm window, 5 seconds

'^ Open door test (both north and south hangar doors partially open)

* Open door test (only south hangar door partially open)

T - Trouble condition

straightened and immediately filled the test bay, thus inundating the upper detectors and causing a

trouble condition. The second open door experiment using the 2.5 m diameter pan produced alarm

times from 39 s at the highest elevation to 47 s at the lowest elevation. In this experiment only detector

B6 sensed a trouble condition. The lower graph in Figure 114 shows the results for the 2.5 m diameter

fire tests.

The larger test fires conducted using the 3.0 m x 3.0 m pan produced alarm times that ranged from

27 s to 33 s at the highest elevation and from 74 s to 107 s at the lowest elevation. The alarm time

value for detector B6 seems to be the only anomaly in these data. For this particular test, the analog

signal produced by the detector indicates that the detector was completely obscured by the smoke at 65

s. This condition remained until about 100 s. When the smoke abated enough, the detector reentered

alarm stage, thus producing an alarm time of 107 s. The upper graph in Figure 115 shows the results for the 3.0 m x 3.0 m fire tests. A single experiment was performed using the 4.6 m x 4.6 m pan. This experiment produced alarm

times from 30 s at the highest elevation to 75 s at the lowest elevation. The lower graph in Figure 115

shows the results for the 4.6 m x 4.6 m fire test.

Additional figures are shown that provide information on the relationship between the larger fire sizes

and detector response times at various elevations in the test bay. Figure 116 shows the response of

detectors at 1 .3 m and 1.9 m below the ceiling peak. Figure 1 17 shows the response of detectors at the

4.2 m and 10.9 m elevations. These figures include the results from tests run with both JP-5 and JP-8
4 Cold Climate - 22 m Facility 233

E<

o

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120

90

E

SS<

o

E

60 -

30

£.\J 2.0 m diameter pan

O Test 18, JP-5 o

90 -

60 - O

O

O

• O

30 -

n

1 1 1 1 1.3 1.9 4.2

Distance Below Ceiling (m)

2.5 m diameter pan

O Test 14, JP-5

El Test 1 6

** (open door), JP-5 A Test 1 9 " (open door), JP-5

^ A k

1.3 —I

1 1.9 4.2

Distance Below Ceiling (m)

10.9

o

A

10.9

Figure 114. Projected beam activation times for 2.0 m and 2.5 m diameter test fires,

including open door experiments.
234 4 Cold Climate - 22 m Facility

E<

o

a>E

E

<

o

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120

90 -

60

30

3.0 m X 3.0 m pan

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o

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Distance Below Ceiling (m)

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<iu —

4.6 m x4.6 m pan

O Test 21. JP-5

90 -

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60 -

- o

o

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1

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Distance Below Ceiling (m)

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Figure 1 15. Projected beam activation results for 3.0 x 3.0 m and 4.6 m x 4.6 m test fires.
4 Cold Climate - 22 m Facility 235

<

<uE

3.0

<

B

0)E

3.0

6.0

6.0

ou

1.3 m Below Ceiling

O Detector B7

60 -

o

o

30 - o

n -J

1 1 1 1 9.0

Fire Size (MW)

12.0 15.0

ou

1.9 m Below Ceiling

O Detector B1

Detector B2

60 - Q

O Q

Q

30 - 8 °

U 1 I

1 1 9.0

Fire Size (MW)

12.0 15.0

Figure 116. Projected beam activation results at 1.3 m and 1.9 m elevations, with respect to

fire size.
236 4 Cold Climate - 22 m Facility

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Figure 1 17. Projected beam activation results at 4.2 m and 10.9 m elevations, with respect

to fire size.
4 Cold Climate - 22 M Facility 237

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150

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El

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Test Number (In lincreasing order of HRR)

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238 4 Cold Climate - 22 m Facility

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240 -

180 -

120

60

T

t

o Detector B3, 4.2 m depth, 5.3 m north Q Detector B4, 4.2 m depth, 5.3 m south T Detector B5, 10.9 m depth, 5.3 m north Detector B6, 10.9 m depth, 5.3 m south

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Test Number (In increasing order of HRR)

Figure 119. Projected beam smoke detector results, 30% sensitivity setting.
4 Cold Climate - 22 M Facility 239

fuels.

Figures 1 18 and 1 19 include all detectors with respect to HRR. All tests are shown, including test fires with open door configurations and test fires using JP-8 fuel. Figure 118 shows those detectors with a 20% sensitivity setting. Figure 119 shows those detectors with a 30% sensitivity setting.

4.4.3 Response of Photoelectric Smoke Detectors

It is important to note that photoelectric smoke detectors would not normally be installed in an aircraft

hangar for a variety of reasons. However, these experiments included photoelectric smoke detectors to help analyze their response in high bay applications. This may be useful in evaluating detector

response and spacing in other high bay occupancies. The locations of the smoke detectors in the 22 m

high facility are shown in Figure 57.

The spacing of detectors from the source of the fire was slightly different along the north/south axis

than the east/west axis due to the location of the permanent draft curtains. Both axes had detectors

located at 3.1 m and 6.1 m within the draft curtain. The detectors located at 9.1 m along north/south

axis were located outside the draft curtain. The detectors located at 9.1 m, 12.2 m, 15.2 m, and

18.3 m along the east/west axis were all located within the draft curtain. These distances were selected

in order to achieve the most uniform spacing from the edges of the draft curtains.

4.4.3.1 Fires less than 3 MW (tests 1-13)

Tests 1 through 13 all produced heat release rates less than 3 MW. Tests 1, 2 and 9, which were 0.3 m

x 0.3 m pans with heat release rates of approximately 100 kW, did not activate any of the photoelectric

smoke detectors. Tests 3 through 8, and 10 through 13 all produced sufficient smoke to activate the

photoelectric smoke detectors. The response times of the photoelectric smoke detectors for fire sizes

less than 3 MW are shown in Table 61.

Effects of Ceiling Curvature

Because the 22 m hangar has a barrel-shaped roof, not all of the smoke detectors were at the same

elevation with respect to the floor. All detectors were mounted approximately 0.3 m below the ceiling.

The effects of ceiling curvature can only be analyzed for the detectors at 3. 1 m and 6.1m from fire center due to the presence of the draft curtains. The detectors along the east/west axis at 3. 1 m and 6.

1

m from the fire center were installed at a height of 21 .9 m and 21 .7 m respectively above the floor. A

comparison of the average response times for the detectors along the north/south axis versus those

along the east/west axis shows that the ceiling curvature had no significant effect on the response times

of the photoelectric smoke detectors located 3. 1 m and 6. 1 m from fire center. This is illustrated graphically in Figures 120 and 121. A comparison of detector response times beyond 6. 1 m from

plume center could not be evaluated with respect to the effect of ceiling curvature because of the

configuration of the draft curtains.
240 4 Cold Climate - 22

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242 4 Cold Climate - 22 m Facility

Table 61. Response times (s) of photoelectric smoke detectors installed in 22 m high facility for

fires less than 3 MW

Location 3.1m

(10 ft)

6. 1 ill (20 ft)

9. i m

(30 ft)

9.1 m

(outside DC)

12.2 m

(40 ft)

15.2 m

(40 ft)

18.3 m

{60 ft) Test # 3 - 0.6 m X 0.6 m JP-5 (0.9 MW)

North 57 «5 -

S 382 -

; - East 53 78 123 - 132 144 178 South 69 82 - 1 386 - - - West 66 82 119 145 140 190

Test # 4 - 0.6 m X 0.6 m JP-5 (0 8 MW)

North 51 Si -

\ 333 - - - East 77 106 114 139 160 201

South 1^1 S9 E 271 - West 110 114 127 172 127 210 Test#5-0.9mx0.9niJP-5(L7MW) • | NOTt{) 36 36 - iiii:i:25S;i:i*i;ii? » -wi;iii - East 28 41 57 66 82 95 South 32 30 - - -:::••:• - West 28 49 70 79 87 108

Test #6 -0.9mx 0.9m JP-5 (L4MW) | North 4J 41 - 103 - iiiiis^iiiiiii - East- 41 46 66 - 70 87 104 South 32 45 - 17Q . ...... ,-. .,, - West 33 49 49 74 79 108 Test#7-1.2mxL2mJP-5(2.8MW) | N0ttl» 4G 48 - '' - - East 36 44 57

! ''^ 69 73

South 4Q 48 - 140 - - West 44 49 53 78 65 91 Test#8- 1.2mx L2mJP-5(2.5MW) | mmmtih 4J 37 - '78 - '^mmi Mm: - East 33 46 46 62 62 70 mmmmit 37 45 - 145 ... West 33 37 54 63 66 94

Test # 10 - 0.6 m X 0.6 m JP-8 (0.6 MW) | SiissSisNorth 192 J43 - ' - MMMmMMm

East 196 183 183 158 l')2 217

IxSSHftSbuth ISO 444 - 404 - xSsliiiiiiii

West 193 193 229 - 292 217 230

Test # 1 1 - 0.6 m X 0.6 m JP-8 (0.8 MW) |

ifi/V North :; "

i85::;::i;i:l mMMmMfM WM&MMiii' :;556--- : - ::;:;g::iiiiiiii East 90 148 136 1.36 1X1 164

:S;: South: ;;*H;xx Wmm^mim WMmM^M- iP 331;: : West 98 206 198 i 215 190 198 Test* 12 -0.9 m X 0.9 m JP-8 (1.6 MW) | m: North 45 : ::g: mmmm^v r:

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.,

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Suuth S7 74 WMMMmM m. .:..:

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: iigsiiiliiiiiii West 62 66 70 87 75 100

Test # 13 - 1 .2 m X 1 .2 m JP-8 (2.7 MW) I iilNorlh : :: 49 immi WM5M»mi WimM^: -: mmmm - -

East 41 50 50 - 62 66 78

Suuih .17 66 - 128 SxsSi West 37 50 55 " 62 58 79 detector did not activate no detector installed
4 Cold Climate - 22 M Facility 243

Effect ofDraft Curtains

To analyze the effects of the draft curtains, the detectors located along the east/west axis were compared to those along the north/south axis at a distance of 9. 1 m from fire center. The north/south

detectors were located outside the draft curtain. The draft curtain had a measurable effect on the

response time of the photoelectric smoke detectors for fire sizes less than 3 MW. This can be seen

graphically by comparing Figure 122 with Figure 123. The detectors located inside the draft curtain

responded an average of 2.3 times faster than those detectors located outside the draft curtain.

Ejfect ofFuel Type

To study the effects of fuel type on photoelectric detector response, the response times of tests 3 and 4

(0.6 m X 0.6 m, JP-5) were compared to those of tests 10 and 11 (0.6 m x 0.6 m, JP-8). Figure 124

shows that the JP-5 fires were consistently detected earlier than the JP-8 fires, although the wind

conditions may have affected the results as much as the fuel type.

Effect of Spacing

Analysis of Table 61 indicates that fire sizes less than 1 MW were difficult to detect via the

photoelectric detectors in the 22 m hangar. However, for all fire sizes greater than 1 MW, detector

spacing of 12.2 m (40 ft) would be acceptable. This confirms the results reported for the 15 m hangar

as stated in section 3.

4.4.3.2 Fires greater than 3 MW (tests 14-21)

Tests 14 through 21 generated heat release rates greater than 3 MW. The response times of the

photoelectric smoke detectors for fire sizes greater than 3 MW are shown in Table 62.

Open Door Vs. Closed Door

A comparison of test 14 with test 16 (both 2.5 m diameter pan fires) can be used to investigate the

effects that open hangar doors have on photoelectric detector response. The smoke detector response

with the hangar doors open was actually faster than with the doors closed. For example, in test 16 the

average response time of the detectors located 3.1 m from fire center was 51s compared to an average

response time of 65 s in test 14.

Effect of Ceiling Height

To analyze the effects of ceiling height, one can compare the average smoke detector response times

for the 2.0 m and 2.5 m diameter pan fires in both the 15 m and 22 m hangars. For the 2.0 m diameter

pan fire, the average response time of the smoke detectors located 6.1m from the fire center in the

15 m hangar was 35 s compared to 50 s in the 22 m hangar. Similarly for the 2.5 m diameter pan fire,

the average response time of the smoke detectors located 6.1 m from the fire center in the 15 m hangar was 31s compared to 69 s in the 22 m hangar. While this comparison shows a significant difference in average response times, the difference is not solely attributable to ceiling height. It does not account

for the differences in ambient air and fuel temperatures, ignition sequence, nor the difference in the

volume of the draft curtain areas between the two experimental sites.
244 4 Cold Climate - 22

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246 4 Cold Climate - 22 m Facility

3.0 m

BJP-5, 0.93MW

JP-5, 0.77M\A/ DJP-8, 0.6MW

aJP-8, 0.77MW

6.1 m

Distance from fire (m)

9.1m

Figure 124. Comparison of JP-5 to JP-8 fuels on photoelectric detector response time for fire sizes

less than 3 MW .
4 Cold Climate - 22 m Facility 247

Table 62. Response times (s) for photoelectric smoke detectors installed in 22 m high facility to

fire size greater than 3 MW

: Location 3.1 m

(10 ft)

6.1 m

(20 ft)

9.1 m

(30 ft) 9.1m(outside DC)

12.2 m

(40 ft) 15.2m

(40 ft)

18.3 m

(60 ft) Test # 14 - 2.5 m diameter JP-5 (7.9 MW) | iiiporih 59 68 .-.,,,..,,,.,,,, ... . 101.^ .:.: .................... -.:: - East 64 72 77 - 80 89 93

iiiiiSbum 76 68 MimmM&M wmmmmm MMwMyMmi WB::W'-Wy^MyM - West 60 69 73 - 89 89 97

Test# 15 -3.0 m X 3.0 m JP-8 (15.7 MW) | North 47 51 mmmm^m Mmmm&mw - East 49 49 56 - 68 72 85

South 43 56 - 97

....,,,.^,...,.,.. :,....,. - - West 44 49 53 - 65 65 11

Test # 16 - 2.5 m diameter JP-5 (7.0 MW) | North 50 46 - 75 - - - East 50 54 54 - 59 67 71 SouUi 54 58 - 83: - - - West 51 51 54 - 54 59 63

Test # 17 - 3.0 m X 3.0 m JP-8 (14.3 MW)

North 29 33 - 71 - - - East 38 42 54 - 54 67 71 South 29 38 - 121 - w West 25 30 42 50 55 59

Test # 18 - 2.0 m diameter JP-5 (4.9 MW) | North 54 50 - 84 - ~ - East 46 75 - 135 102

South 46 54 - 231 - - - West 51 46 59 - 63 71 80

Test # 19 - 2.5 m diameter JP-5 (9.1 MW)

North 56 65 - 102 - - - East 54 82 73 - 61 98 103 South 52 52 - 115 - - - West 61 45 45 - 65 61 69

Test # 20 - 3.0 m X 3.0 m JP-5 (14.6 MW)

North 36 40 - 77 - - - East 41 45 52 - 61 69 81 South 36 44 - 81 - ~ mmMymMm:::

West 41 41 49 - 57 65 70

Test # 21 - 4.6 m X 4.6 m JP-5 (33 MW)

North 34 34 76 WMMMmMM.

East 40 51 51 59 67 63

South 38 55 - 109 - - - West 35 35 40 - 51 56 68

detector did not activate no detector installed
248 4 Cold Climate - 22 M Facility

4.4.4 Response of Heat Detectors

The heat detectors utilized in the 22 m facility included the same type of addressable 57 °C (135 °F)

rate-compensated, fixed-temperature heat detectors used in the 15 m hangar experiments, as well as 93 °C (200 °F) hard wired, thermistor-type heat detectors. The 57 °C heat detectors would not

normally be suitable for a high bay hangar application, but were chosen to represent the lowest possible

temperamre rating which may be used in an aircraft hangar. The 93 °C detectors were selected to represent the highest temperature heat detectors typically installed in a high bay hangar.

The spacing of the detectors beyond 6.1m from the source of the fire was slightly different along the

north/south axis than the east/west axis because of the presence of the draft curtain.

None of the 57 °C or 93 °C heat detectors responded in any of the experiments where the fire size was

less than 3 MW. Fire sizes with heat release rates greater than 3 MW activated both the 57 °C and

93 °C heat detectors. Table 63 shows the response times of the 57 °C and 93 °C heat detectors for all experiments conducted in the 22 m hangar.

Ejfect of Ceiling Curvature

The heat detectors were installed adjacent to the photoelectric smoke detectors whose mounting details

with respect to the ceiling curvature were described earlier in section 4. Since the detectors within the

draft curtain along the north/south axis could only be installed a maximum distance of 6.1 m from the

plume, the analysis of the curved ceiling effect on heat detector response must practically be limited to those detectors located within 6.1 m of the plume centerline. Figure 125 graphically depicts the effects of the curved ceiling on the response time of the 57 °C heat detectors for five of the larger experiments

conducted in the 22 m hangar. This shows that the ceiling curvature had no significant impact on the

response times of heat detectors located 6.1m from plume centerline. The shorter response time in the

N-S direction is probably due to the presence of the draft curtains and not the absence of ceiling curvature.

While additional heat detectors installed along the east/west axis at distances of 12. 2m, 15. 2m, and

18.3 m were mounted at lower elevations than those at 6.1 m, there are no comparative heat detectors

along the north/south axis because of the draft curtains. One can certainly look at the response times of

the detectors beyond 6.1 m as shown in Table 63, but the reader is cautioned to avoid a direct

comparison unless it also considers the greater distance of these detectors from plume centerline.

Ejfect of Draft Curtains

Table 63 shows the response times of the 57 °C and 93 °C heat detectors outside the draft curtain.

These were installed along the north/south axis at a distance of 9. 1 m from the plume centerline. The

table shows that not a single 93 °C heat detector responded outside the draft curtain for any of the

experimental fires. The table also shows that several of the 57 °C detectors activated outside the draft

curtains. However, the response times of those detectors outside the draft curtain are twice as long as

the 57 °C detectors located inside the draft curtain as shown in Figure 126. This clearly demonstrates

the ability of the draft curtain to confine the heat within the boundaries of the draft curtain. This also

shows the ability of the draft curtains to limit the number of sprinkler heads activated in adjacent draft

curtain areas.
4 Cold Climate - 22 m Facility 249

Table 63. Response times (s) of heat detectors installed in 22 m high facility test area for fire sizes greater than 3 MW

location 1 3.1 in | 6Am 9.1 m ^*1 m <{Httside DC^ 12.2 m 15.2 m 18.3^m

'Detector '5^ ^^ '"? or-i^T o^ 93 °C 57 «C 93 °F 57 "C 93 °C 57 "C 93 °C 57 "C 93 °C 57 ''C 93 °C

Test #14- 2.5 m Diameter JF-5 7,9 MW

North U9 140 '*^ ~ 645 >n»- ~ >V -

ScHifh 94 629 181 A-mt- ~ 653 ^ ~ /«W- ~ /Mrf- ~

East 128 236 198 282 ^ ~ 33^ 331 474 468 361 565

West 111 141 286 ** ~ 332 349 641

Test #15-3.0 m X 3.0 m JP-5 15.7 MW

North 89 155 98 227 ~ 256 »*• ~ »K ~ **•' ~ $mk 82 127 % 222 'N^ ~ 269 &V ~ ' -*V ~ ^*^ ~

East 90 344 106 103 m 150 ~ 156 142 189 161 169 199

West 90 149 102 216 H!^ 309 '- 128 344 157 215

Test #1^* 2.S m JWameter S1?-B 7,0 MW

North 134 134 ^ ~ Hot ~ MmC ~ 4W ~

South ^ *w ~ A. •M*/ ~ 4W - *%*- ~

East 130 ^ ~ #

Wm ^ 174 Jtm^ ~ ; Test #17-3.0 m X 3.0 m JrP-8 14.3 MW

North 75 158 75 258 r^ ~ 241 ^ ~ ^W ~ yw ~

50t«h m 124 80 *V ~ ""W <«>< ~ 4M ~ M,^ -

East m^ 350 80 126 156 ^ ~ 135; 143 17$ 173 ,_,.

West n 160 88 il3 293 «. - 126 316 151 456 196

rmn^2,omJ> aiweterJF^ 4.^MW:"""'""

North 292 376 ^ W ^ ~ J-^mt - mt ~

So&tii 310 481 >-«K ~ ~ ^ - )**» ~

East 310 473 482 *<' ~ # ,,

West 302 368 # M^ ~ ""*'"

Test #19- 2.5 m Diameter JP-5 9.1 MW

North 246 322 ** - Ji-f - f^ ~ 4>^ ~

^tHith I5i 196 ^ ~ ^ >M» ~ ~ ~

East 243 330 - ~

West 188 168 305 ''ft 310

Tmm^Mm%mmms i4iiiiiii

North iiiiii 186 90 286 ^ ^ 261 ~ - ~ ~ ~

South 109 83 237 ~ 278 ^^^v ~ ~ ~

East 78 472 91 108 95 150 *v ~ m 137 170 174 161 184

West 70 137 91 245 124 441 J*** - 137 546 149 558 195 ~ No heat detector at that location. Heat detector at that location did not activate.
250 4 Cold Climate - 22 m Facility

210

180

150

120

7.9 MW 15.7 MW 14.3 MW 14.6 MW 33 MW

Heat Release Rate (MW)

Figure 125. Comparison of 57 °C heat detectors located 6.1 m from the plume centerline to determine effect of curved ceiling in 22 m high facility.
4 Cold Climate - 22 M Facility 251

Ejfect of Fuel Type

A comparison of the heat detector response times for similar sized using JP-5 and JP-8 fuels, showed

no significant difference in the response times of either the 57 °C or 93 °C heat detectors.

Ejfect of Spacing

Figure 127 shows a comparison of both the 57 °C and 93 °C average heat detector response times at 3.1 m and 6.1 m from plume centerline. With the exception of the 7.9 MW fire, the figure shows little or no difference between the response times of the detectors at 3. 1 m or 6. 1 m from the fire. (Note: the

bar on Figure 127 which depicts the response time of the 93 °C detector at 6. 1 m from the 7.9 MW

fire represents the response time of only one detector. Further analysis of Table 63 indicates that the

detector was faulty. Consequently, the data should show no response of the 93 °C heat detector

located 6.1 m from plume centerline in the 7.9 MW fire.) This again indicates that a detector spacing

of 12.2 m between detectors would be a suitable spacing for a 22 m hangar. Further analysis of Figure

127 also shows the difference in average response times between the 57 °C and 93 °C heat detectors.

For all the test fires under 33 MW, the average response time of the 93 °C detectors was over twice as long as the response time of the 57 °C detectors.

Comparison ofHeat Detector Response to Quick Response Sprinkler Heads

To date, existing pre-action sprinklers in military aircraft hangars have been activated primarily by the use of rate-compensated heat detectors with a listed temperature rating of approximately 93 °C. The

existing closed head sprinklers have a temperature rating of 141 °C. These tests indicate that 79 °C

quick response automatic sprinklers should be used if the overhead sprinklers are to provide any

cooling effects for aircraft adjacent to the fuel spill area. Hangars located in cold climates require the use of pre-action type sprinkler systems whose alarm valves (i.e., deluge valves) must be activated by a

detection system. Consequently, if 79 °C quick response sprinklers are to be used, it is important to select the appropriate temperature heat detectors in order to ensure activation of the deluge valves prior

to the response of a large number of sprinkler heads. In most hangar fire protection designs, the

optical flame detectors will also activate the deluge valves on the pre-action sprinkler risers. Nevertheless, it is still essential that the temperature rating of ceiling mounted spot-type heat detectors

be closely matched to that of the closed-head sprinklers.

Figures 128 and 129 show the average response time comparison of the 57 °C and 93 °C heat detectors

with the 79 °C quick response sprinklers at 3. 1 m and 6.1m from plume centerline. Although the

57 °C heat detectors always activated prior to the 79 °C sprinklers, they are typically a poor choice for

aircraft hangars because they will often activate during hot summer months. As shown in the figures,

the 93 °C sprinklers responded after the sprinklers which is unacceptable. These figures suggest that the appropriate temperamre rating for the heat detectors would be approximately in the 71 °C range.

Open Door vs Closed Door

A comparison of test 14 with tests 16 and 19 (all using 2.5 m diameter pan fires) can be used to investigate the effects that open hangar doors have on heat detector response. Both hangar doors were

open in test 16 while only one hangar door was open in test 19. Contrary to the response of the

photoelectric smoke detectors, the open door experiments had longer heat detector response times tiian
252 4 Cold Climate - 22 M FACiLnY

660

600

540

480

420

360

300

240

180

120

'9.1 m (inside draft curtain)

I9.I m (outside draft curtair

IHeat Release Rate

Figure 126. Effect of draft curtain on 57 °C heat detector response time.
4 Cold Climate - 22 m Facility 253

660

600

540

480

420

360

Time (s)

300

240

180

120

57 C (at 3.1 m)

57 C (at 6.1 m)

n93C(at3.1 m)

93 (at 6.1 m)

7.9 MW 14.3 MW 14.6 MW 15.7 MW 33 MW

Figure 127. Comparison of response times of 57 °C and 93 °C heat detectors located at 3.1m and 6.1 m from plume center.
254 4 Cold Climate - 22 M Facility

a similarly sized closed door experiment. For example, in test 14, the average response time of the

57 °C detectors located 3.1m from the fire was 113 s compared to 146 s in test 16 and 207 s in test 19. In addition, none of the 93 °C detectors activated in either of the open door experiments, yet five

of the higher temperature detectors activated in test 14. A similar comparison using the 57 °C

detectors shows that all 18 detectors activated in test 14, while tests 16 and 19 only activated 4

detectors and 10 detectors respectively.

Ejfect of Ceiling Height

Attempts to compare the heat detector response times between the 15 m and 22 m hangars for the

purpose of analyzing the effects of ceiling height must also acknowledge the differences in ambient air and fuel temperatures, as well as the difference in the volume of the draft curtain areas. The typical

ambient temperature for the 15 m hangar was about 29 °C while it was about 11 "C for the 22 m

hangar. With those limitations understood. Figure 130 shows a comparison of the 57 °C heat detector

average response times for the experiments in the 15 m and 22 m hangars at distances of 3. 1 m, 6. 1 m,

and 9.1m from plume center for comparable fire size.

Ejfect of Fire Size

Figure 131 shows the effects of fire size on the average response times of the 57 °C heat detectors

located 3.1 m and 6.1 m from plume centerline. As fire sizes increased above 14.3 MW, the

difference in average heat detector response time at the two distances decreased. For example, Figure

131 shows the average detector response time to be approximately 68 s in the 14.3 MW fire compared

to 73 s in the 33 MW fire. For these large fires the detection system is responding during the fire growth stage since it took between 50 s and 80 s for full-pan involvement to occur.
4 Cold Climate - 22 m Facility 255

660

600

480

420

360

7.9 MW 15.7 MW 14.3 MW 14.6 MW

Heat Release Rate (MW)

33 MW

Figure 128. Activation time comparison of heat detectors to 79 °C quick response sprinklers located

3.1 m from plume center for tests conducted in 22 m high facility.
256 4 Cold Climate - 22 m Facility

300

270

240

210

.V'

7.9 MW 15.7 MW 14.3 MW 14.6 MW

Heat Release Rate (MW)

»57»C HD

79 "C AS

1^93 "C HD

33 MW

Figure 129. Activation time comparison of heat detectors to 79 °C quick response sprinklers located

6. 1 m from plume center.
4 Cold Climate - 22 m Facility 257

660

600

540

480

420

360

300

240

180

115 m High Facility 122 m High Facility

120

3.0 m 6.1 m

Distance from Fire Center

9.1 m (inside do)

Figure 130. Average response times of 57 °C heat detectors to 2.5 m diameter pan fires conducted

in 15 m and 22 m high facilities.
258 4 Cold Climate -22 m Facility

480

420

360

300

240

180

120

60

>3.1 m

6.1 m

4.9 MW

lllll 7.9 MW 14.3 MW 14.6 MW 15.7 MW 33 MW

Heat Release Rate (MW)

Figure 131. Effects of fire size on 57 °C heat detector response for detectors located 3.1m

and 6. 1 m from plume center in 22 m high facility.
4 Cold Climate - 22 M Facility 259

4.4.5 Response of Optical Flame Detectors

The settings, configuration and mounting height of the combination UV/IR optical detectors were

discussed eariier in section 4 and the locations were shown schematically in Figure 59. The effects of

ceiling height and draft curtains were not evaluated for these detectors because each detector was

mounted approximately 2.44 m above the floor. The physical dimensions of the 22 m hangar permitted

detectors to be located a maximum distance of 45.7 m from the fire center. The response thresholds of

the optical flame detectors were determined for each test fire.

There are three significant facts regarding the controller settings and the physical location of the

detectors that warrant further discussion. First, because the experiments included a variety of fire sizes, detectors were located in three different configurations. Second, the UV/IR controller settings were varied for the 0.3 m x 0.3 m and 0.9 m x 0.9 m pan fires. The main effect of changing the

controller settings is to increase or decrease the detector's range. The controller setting of 0.25 s gate

length, 2 counts per gate, and 3 consecutive gates (0.25/2/3) requires a minimal signal strength of 6

counts occurring in 0.75 s to reach alarm state (8 CPS). The controller setting of 0.25 s gate length, 4

counts per gate, and 4 consecutive gates (0.25/4/4) requires a signal strength of 16 CPS for one second

to reach alarm state from both the UV and IR portions of the detector.

The third factor involves the manner in which the optical flame detectors were aimed during these tests. All experiments were conducted with the optical flame detectors positioned such that each detector had

a direct line of sight to the fire source, with the fuel pan centered in each detector's cone of vision for

optimum response. Consequently, these test results represent the best case response scenario for the

optical detectors. Fires that occur within the detector's cone of vision, but not directly along the

centerline axis will have slower response times and shorter threshold response distances. The response

characteristics will decrease proportionally as the viewing angle increases towards the maximum listed viewing angle of the detector.

General Analysis

The raw CPS data files compiled by Detector Electronics Corporation were examined for response time

from three distinct events. These events are ignition, fiill pan involvement, and steady state burning.

The determination of response time to these three events yields a representation of threshold response

distances to a variety of fire sizes, at various stages of fire growth. The data is presented in this format

to aid design engineers in determining when and at what distance these optical detectors will respond to a growing fire in an aircraft hangar.

For the purpose of analyzing this data, ignition is defined as that time that self-sustained combustion was achieved. Full pan involvement was determined by visual observation, and was considered to be

the time at which the flame front completely covered the fuel surface. The time to steady state burning was calculated using the mass loss measurements recorded by the load cell. Where load cell data was

not available, a conservative estimate of the time to steady state burning was made based on similar size

fires and by analyzing the steady state infrared signature recorded by the optical detectors.

The response times from ignition are listed in Table 64 for JP-5 fueled fires and Table 65 for JP-8

fueled fires. Tables 64 and 65 show pan size, heat release rate (HRR), controller settings, time to full pan involvement from ignition, time to steady state burning from ignition.
260 4 Cold Climate - 22 M Facility

During each experiment all of the UV/IR detectors were repeatedly reset at various times during the

test. The purpose of these resets was to obtain response time data at various stages of the fire (i.e.,

from ignition, full pan involvement from ignition, and steady state burning from ignition). Tables 66

and 67 show the response times corresponding to the first two manual resets after full pan involvement.

Times associated with each reset represents elapsed time from ignition. Tables 66 and 67 also show pan

size, HRR, controller settings, time to full pan involvement from ignition, and time to steady state burning from ignition. In most cases the manual resets occurred after most or all detectors had

responded, or changes had stopped occurring. The average time between resets ranged from 10 s to 30 s. The minimum response time from reset for any detector was 0.3 s, corresponding to the time it takes to actually reset the controller. The number of resets analyzed after achieving full pan

involvement and steady state burning reflects the lowest common denominator (i.e., number of resets)

for the vast majority of experiments. In most cases, response time results for full pan and steady state conditions were taken from the first two manual resets that occurred after these conditions were

reached.

The response times from manual reset after steady state burning are listed in Tables 68 and 69 for JP-5

and JP-8 fueled fires respectively. Tables 68 and 69 also show pan size, HRR, controller settings, time

to full pan involvement from ignition, time to steady state burning from ignition. As with the response

times from full pan involvement, the response time of each detector was determined from a manual

reset during the period of steady state burning.

Threshold Response Distances at Selected Response Times

Threshold response distances from ignition, full pan involvement and steady state burning were

examined at response times of 5, 10, 20, 30, and 45 s. Table 70 shows the threshold response

distances of the optical detectors for each fire size as a function of these selected response times. For

example, if the threshold response distance from ignition for the 0.8 MW fire in test 4 is shown as 45.7

m at 30 s, that means that 45.7 m was the maximum distance at which an optical detector responded

within 30 s for that fire test. (Note that 45.7 m was the maximum distance that the detector could be

located from the fire center within the hangar. The actual usable distance for this type of detector may

exceed this value.) These times were selected to indicate the maximum affective response "distance" at which the detectors responded within a number of response time intervals.

It is believed that the existing testing and approval criteria for optical flame detectors should be

reevaluated. It has been primarily based on two sets of acceptance criteria. First, the Navy and Air

Force design specifications require an optical detector to respond to a 3.0 m x 3.0 m (10 ft x 10 ft) steady state JP-4 fire within 5 s. Factory Mutual requires an optical detector to respond to a 1.5 m x

1.5 m steady state JP-4 fire within 10 s. Based on those requirements, the actual voluntary tests standards which the industry has developed over the years identify the following response distance

thresholds:

Fire Size Response Distance Threshold

0.3 m X 0.3 m (1 ft X 1 ft) 16.4 m (50 ft) 0.6mx0.6m(2ftx2ft) 32.8 ni (100 ft) 3.0 m X 3.0 m (10 ft X 10 ft) 49.2 m (150 ft)
4 Cold Climate - 22 m Facility 261

Table 64. UV/IR response times for JP-5 test fires conducted in 22 m high facility

PAN SIZE (m) FACILITY HRR(MW) TEST No. DETECTOR DISTANCE FROM SOURCE CENTER (m) |

0.3 X 0.3 :;::::::.::22m 0.09 1 9.1 10.7 12.2 13.7 15.2 16.8 18.3 21.3 30.5 45.7

Controller:

Full Pan:

.25/2/3 Response Time (s) 2 s St. State: 110 s4.9 15 17 16 28 29 NR NR NR NR

0,3x0.3 22m 0.08 2 9.1 10.7 12.2 13.7 15.2 16.8 18.3 21.3 30.5 45.7

Controller:

Full Pan:

.25/2/3 Response Time (s) 2 s St. State: 150 s

2.6 6.9 10 10 19 25 40 NR NR NR

0.6x0.6 22m 0.93 3 21.3 22.9 24.4 25.9 27.4 30.5 33.5 36.6 39.6 45.7

Controller:

Full Pan:

.25/2/3 Response Time (s) 15 s St. State: 120 s

22 23 23 26 25 28 29 50 NR NR

0,6x0.6 22m 0.77 4 21.3 22.9 24.4 25.9 27.4 30.5 33.5 36.6 39.6 45.7

Controller:

Full Pan:

.25/2/3 Response Time (s) 15 s St. State: 125 s16 16 25 35 26 37 38 44 59 62

0.9 X 0.9 z2m 1.69 5 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

Controller:

Full Pan:

.25/2/3 Response Time (s) 20 s St. State: 90 s

15 18 20 16 21 24 28 28 31 28

0.9x0.9 22m 1.39 6 2L3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

Controller:

Full Pan:

.25/4/4 Response Time (s) 20 s St. State: 120 s23 34 35 34 37 39 43 56 56 56

1.2 X 1.2 22m 2.81 7 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

Controller:

Full Pan:

.25/4/4 Response Time (s) 30 s St. State: 150 s

25 29 27 27 34 36 39 47 48 54

2:0 bia 22m 4.92 IB Zl.J 30.5 33.5 36.6 39.6 42.7 45.7

Controller:

Full Pan:

.25/4/4 Respoi 40 s St. State:

ise Time (s) 180 s

40 41 41 41 41 41 49 55 55 55

2.5 Dia 22m 7.86 14 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

Controller:

Full Pan:

.25/4/4 Response Time (s) 50 s St. State: 120 s26 33 33 33 38 37 39 48 46 46

2.5 Dia 22m 7 16 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

Controller:

Full Pan:

.25/4/4 Response Time (s) 50 s St. State: 180 s31 31 32 31 35 35 35 45 47 45

2.5 Dia 22m 9.13 19 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

Controller:

Full Pan:

.25/4/4 Response Time (s) 50 s St. State: 120 s

30 33 33 33 44 43 44 50 50 50

3.0x3.0 22m 15.73 15 21.3 24.4 25.9 . 27.4 . 30.5 33.5 36.6 39.6 42.7 45.7

Controller:

Full Pan:

.25/4/4 Response Time (s) 65 s St. State: 330 s15 18 20 20 26 29 30 37 36 41

3.0x3.0 22m 14.6 20 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

Controller:

Full Pan:

.25/4/4 Response Time (s) 65 s St. State: 240 s23 29 29 29 32 34 37 37 41 44

4.6x4.6 22m n/a 21 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

Controller:

Full Pan:

.25/4/4 Response Time (s) 80 s St. State: n/a

23 28 27 27 37 38 41 46 45 45

NOTE: Response

or from a

Full Pan

times are measured in reference to elaj

controller reset for full pan and steady and Steady State times are the time to r

3sed time from "time zero"(mark time) for ignition response

state responses. jach that respective state and are measured in reference to

" ime zerc "(mark time).
262 4 Cold Climate - 22 m Facility

Table 65

UV/IR response times for JP-8 test fires conducted in 22 m high facility

PAN SIZE

(m) FACILITY HRR (MW) TEST No. DETECTOR DISTANCE FROM SOURCE CENTER (m)

0.3 xO.3 22m 0.18 9.14 10.67 12.2 13.7 15.2 16.8 18.3 21.3 30.5 45.7

Controller: .25/4/4 Response Time (s) 25.6

Full Pan: 2 s St. State: 120 s

43.6 44.1 59.8 74.6 NR NR NR NR NR

0.6x0.6 22m 0.6 10 21.3 24.38 25.9 27.4 30.5 33.5 36.6 39,6 42.7 45.7

Controller: .25/2/3 Response Time (s) 11.5

Full Pan: 15 s St. State: 120 s

17 18.5 21.8 18.5 34.7 36.2 36.4 NR NR

0.6x0.6 22m 0.77 11 21.3 24.38 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

Controller: .25/2/3 Response Time (s) 20.8

Full Pan: 15 s St. State: 120 s

22.8 27.1 32.4 23.3 38.8 39.2 48.3 54 NR

0.9 X 0.9 22m 1.62 12 21.3 24.38 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

Controller: .25/2/3 Response Time (s) 18.2

Full Pan: 20 s St. State: 180 s

21.1 25.4 20.9 29.8 32 34.8 35.3 35.2 35.1

1,2x1.2 22m 2,65 13 21.3 24.38 25.9 27,4 30.5 33.5 36,6 39,6 42.7 45.7

Controller: ,25/4/4 Response Time (s) 24.1

Full Pan: 30 s St. State: 120 s

25.1 32.1 24.6 32,6 32,9 39,2 49,4 50,1 49,5

3.0x3,0 22m 14,3 17 21.3 24.38 25.9 27.4 30.5 33.5 36,6 39,6 42,7 45.7

Controller: ,25/4/4 Response Time (s) 16.4

Full Pan: 50s St, State: 270s

22,7 23,2 22.9 27.3 26 28.2 33,5 30,6 40.4
4 Cold Climate - 22 m Facility 263

Table 66. UV/IR response times corresponding to first two manual resets after full pan

involvement for JP-5 test fires conducted in 22 m high facility

"PAN SIZE"

(m)

mciLifY' 'HJtlR'PW) TEST No. DEtlJCTOR DISTANCE FROM SOURCE CENTER (m)

0.3x0.3 22m 0.09 1 9.14 10.67 12.2 13.7 15.2 16.8 18.3 21.3 30,5 45,7

1st Reset 56.5 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.8 1 NR NR NR

2nd Reset 72.1 s 0.3 0.3 0.3 0.3 0.3 0.3 9.1 NR NR NR

Controller: .25/2/3

Full Pan: 2s St. State: 110 s 0.3x0.3 22m 0.08 1 2 9.14 10.67 12.2 13.7 15.2 16.8 18.3 21,3 30.5 45.7

1st Reset 70.6 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.8 2.3 2,5 NR NR

2nd Reset 93.1 s 0.3 0.3 0.3 0.3 0.6 0.8 0.8 4.1 NR NR

Controller: .25/2/3

Full Pan: 2s St. State: 150 s 0.6x0.6 22m 0.93 1 3 21.3 22.86 24.4 25.9 27.4 30.5 33.5 36.6 39.6 45,7

1st Reset 67.7 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 1.9 1.1 4.1 NR NR

2nd Reset 81.3 s 0.3 0.3 0.3 0.3 0.3 1.8 0.3 0.8 NR NR

Controller: .25/2/3

Full Pan: 15 s St. State: 120 s 0.6x0.6 22m 0.77 1 4 21.3 22.86 24.4 25.9 27,4 30.5 33.5 36.6 39.6 45.7

1st Reset 76.4 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0,3 0.3 1.1 1,1 2nd Reset 95.3 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 6.8 NR

Controller: .25/2/3

Full Pan: 15 s St. State: 125 s 0.9x0.9 22m 1.69 1 5 21.3 24.38 25.9 27.4 33.5 36.6 39.6 42.7 45.7

1st Reset 60.2 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 2nd Reset 74.8 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

Controller: .25/2/3

Full Pan: 20 s St. State: 90 s 0.9x0.9 22m 1.39 1 6 il.3 24.38 25.^ 27.4 30.5 33.5 36.6 39.6 42.7 45.7

1st Reset 96 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1.9 2nd Reset 117.2 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1.1 4.6 4.6

Controller: .25/4/4

Full Pan: 20 s St. State: 120 s 1.2x1.2 22m 2.81 1 7 21.3 24.38 25.9 27.4 30.5 33,5 36.6 39.6 42.7 45.7

1st Reset 62.7 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0,3 0.3 0,3 0.3 0.3 2nd Reset 79.5 s 0.3 0.3 0.3 0.3 0.3 0,3 0.3 0,5 0.5 0.5

Controller: .25/4/4

Full Pan: 30 s St. State: 150 s 2.0 Dia .22m; 4.92 1 18 21.3 24.38 25.9 27.4 30.5 .33.5 36.6 39.6 42.7 45.7

1st Reset 79.5 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1.8 0.3 3.1 2nd Reset 95.4 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

Controller: .25/4/4

Full Pan: 40 s St. State: 180 s 2.5 Dia 22m 7.86 1 14 21.3 24.38 25,9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

1st Reset 58.4 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0,3 0.3 2nd Reset 70.6 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0,3 0.3

Controller: .25/4/4

Full Pan: 50 s St. State: 120 s
264 4 Cold Climate - 22 m Facility

PAN SIZE

lrn\ FACILITY HRR(MW) TEST No. DETECTOR DISTANCE FROM SOURCE CENTER (m) 1

2.5 Dia 22m 7 16 ii.3 i4.38 25.^ 27.4 50.5 33.5 36.6 w.r 42.7 45.-7

1st Reset 60.8 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1 1 1 2nd Reset 82.0 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.8 1.3 Controller: .25/4/4

Full Pan: 50 s St. State: 180 s 2.5 Dia 22m 9.13 1 19 21.3 24.38 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

1st Reset 77 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1.1 2nd Reset 93.2 s 0.3 0.4 0.3 0.3 0.4 0.3 0.3 0.3 0.4 0.4

Controller: .25/4/4

Full Pan: 50 s St. State: 120 s 3.0 X 3.0 22m 15.73 1 15 21.3 24,38 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7;:

1st Reset 84.4 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 2nd Reset 96.0 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

Controller: .25/4/4

Full Pan: 65 s St. State: 330 s • 3.0x3,0 22m 14.6 1 20 21.3 24.38 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45,7

1st Reset 66.7 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 2nd Reset 79.3 s 0.3 0.4 0.4 0.3 0.3 0.3 0.3 0.3 0.4 0.3

Controller: .25/4/4

Full Pan: 65 s St. State: 240 s 4.6x4.6 22m n/a 1 21 21.3 24.38 25.9 27.4 30.5 33.5 36.6 39,6 42.7 45.7 :

1st Reset 83.1 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.8 2nd Reset 100.5 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

Controller: .25/4/4

Full Pan: 80s St. State:
4 Cold Climate - 22 m Facility 265

Table 67. UV/IR response times corresponding to first two manual resets after ftill pan

involvement for JP-8 test fires conducted in 22 m high facility

^:^;PANSIZE

(m)

FACILITY HRR{MW) TEST No. DETECTOR DISTANCE FROM SOURCE CENTER (m)

0.3 xO.3 22m 0.18 9 9.1 10.7 12,2 13,7 15,2 16.8 18.3 21.3 30.5 45.7

1st Reset 83.5 s Response Time (s) 0.3 0.3 0.3 0.3 0.8 9.9 NR NR NR NR

2nd Reset 99 s 0.3 0.3 0.3 0.3 1.3 6.8 NR NR NR NR

Controller: .25/4/4

Full Pan: 2s St. State: 120 s

0.6 X 0.6 22m 0.6 10 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39,6 42.7 45.7

1st Reset 45.3 s Response Time (s) 0.3 0.3 0.3 .0.3 0.3 2.0 3.8 NR NR NR

2nd Reset 65.3 s 0.3 0.3 0.5 0.3 0.3 0.5 1.6 6,6 22.6 NR

Controller: .25/2/3

Full Pan: 15 s St. State: 120 s 0.6x0.6 22m 25.9

::.:^;.:.x..:-:. 0.77 11 21.3 24,4 30,5 33.5 36.6 39.6 42.7 45.7

1st Reset Response Time (s) NO RESETS PRIOR TO STEADY STATE

2nd Reset

Controller: .25/2/3

Full Pan: 15 s St. State: 120 s

f> V n T)m 1 (n n Tl "X '^^ Q 11 A in ^ XX ^ "Xf, « "^Q f» Al 1 A^ 7

1st Reset 46.8 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 2.9 3.1 3.4 17.4 2nd Reset 82.9 s 0.3 0.3 0.3 0.3 0.3 0.4 0.4 3.1 5.1 4.9

Controller: .25/2/3

Full Pan: 20 s St. State: 180 s 1.2x1.2 13

-^^x-^::;::.- ... ._. . . ... .... .. , .. , .. _ .. -1 22m 2.65 21.3 24.4 25.9 27.4 30.5 33.5 3&.6 39.6 4Z.7 45.7 :

1st Reset 66 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 5.0 8.2 8.3 2nd Reset 95.5 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1.1 7.4 7.4

Controller: .25/4/4

Full Pan: 30 s St. State: 120 s

1 1 1 3.0x3.0 22m 14.3 17 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

1st Reset 54 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 2nd Reset 72.5 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

Controller: .25/4/4

Full Pan: 50 s St. State: 270 s
266 4 Cold Climate - 22 M Facility

Table 68. UV/IR response times from manual reset after steady state burning for JP-5 test fires conducted in 22 m high facility

PAN SIZE FACILITY HRR(MW) TEST-^lNto-- DETECTOR DISTANCE FROM SOURCE CENTER (m)

(m) 0.3x0.3 22ni 0.09 1 9.14 10.7 12.2 13.7 15.2 16.8 18.3 21.3 30.5 45 72

1st Reset 116.1 s Response Time (s) 0.3 0.3 0.3 0.3 0.6 0.3 2.8 NR NR NR

2nd Reset 145.5 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 5.3 NR NR

Controller: .25/2/3

Full Pan: 2s St. State: 110 s

: 0.5x6.3 ilm 0.08 1 1 9.14 10.7 12.1 13.7 ^\i:r 16.8 18.3 11.3 30.5 45.71

1st Reset 172.8 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 2.1 6.1 NR NR

2nd Reset 502.1 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1.3 NR NR

Controller: .25/2/3

Full Pan: 2s St. State: 150 s 0.6 X 0.6 22m 0.93 1 3 21.3 12.9 24.4 25.9 27.4 30.5 33.5 36.6 39.6 45.72

1st Reset 128.7 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 4.6 8.6 8.8 2nd Reset 146 s 0.3 0.3 0.3 0.3 0.3 1.8 3.6 3.3 3.8 4.3

Controller: .25/2/3

Full Pan: 15 s St. State: 120 s 0.6x0.6 22m 0.77 1 4 21.3 22.9 24.4 25.9 27.4 30.5 33.5 36.6 39.6 45.72

1st Reset 158.6 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 2nd Reset 182.1 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1.5 1.8 Controller: .25/2/3

Full Pan: 15 s St. State: 125 s 0.9x0.9 22m 1.69 1 5 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.72:;

1st Reset 104.4 s Response Time (s) 0.3 0.3 0.3 0.3 0.8 0.5 0.5 1.8 1.8 1.8 2nd Reset 114.1 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1.5 1.3 1.5 Controller: .25/2/3

Full Pan: 20 s St. State: 90 s 0.9 X 0.9 22m 1i.yy 39 1

\ 6o 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.72:;

1st Reset 144 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1 0.8 1 2nd Reset 158.6 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 17.1 17.1 17.1

Controller: .25/4/4

Full Pan: 20 s St. State: 120 s 1.2 X 1.2 22m 2.81 1 7 21.3 24.4 25,9 27.4 30.5 33.5 36.6 39.6 42.7 45.72;

1st Reset 153.1 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 1.6 2nd Reset 168.6 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 4.6 4.6 4.6

Controller: .25/4/4

Full Pan: 30 s St. State: 150 s 2.0 Dia 22m 4.92 1 18 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.72

1st Reset 182.1 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.5 0.5 0.5 2nd Reset 195.1 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

Controller: .25/4/4

Full Pan: 40 s St. State: 180 s 2.5 Dia i2m 7.86 1 14 21.3 24.4 25.9 17.4 30.5 33:5 36.6 39.6 42.7 45.72

1st Reset 137.9 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 2nd Reset 150.6 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

Controller: .25/4/4

Full Pan: 50 s St. State: 120 s 2.5 Dia 22m 7 1 16

..^.^.. 14.4 15.9 27.4 30.5 33.5 36.6 30.6 41.7 45.71

1st Reset 236.2 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 1.1 3.1 NR NR NR

2nd Reset NO 2ND RESET

Controller: .25/4/4

Full Pan: 50 s St. State: 180 s
4 Cold Climate - 22 M Facility 267

PAN SIZE

(m)

FACILITY HRR(MW) TEST No. DETECTOR DISTANCE FROM SOURCE C:entefi(m)

2JDta 11m 9.13 19 2U 14.4 219 11

A

30.5 33.5 36.6 39.6 42.7 45.71

1st Reset 132.1 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 2nd Reset 160 s 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3

Controller: .25/4/4

Full Pan: 50 s St. State: 120 s "i3-;oT5:(}-- mmmm. mmm^:^..> 15 1 21.3 -^KAT23:9 -UA~ 30.5 13T- 36.6 39.6 I^TT 45.72

1st Reset 2nd Reset NO RESETS AFTER STEADY STATE

Controller: .l'bli,l\

Full Pan: 65 s St. State: 330 s 3.0x3.0 22in 14.6 20 1 21.3 24A 25.9 27.4 30.5 33.5 36.6 39.6 42:7 45.72

1st Reset 258.5 s Response Time (s) 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 0.3 2nd Reset 282.8 s 0.3 0.4 0.4 0.3 0.3 0.3 0.3 0.3 0.4 0.3

Controller: .25/4/4

Full Pan: 65 s St. State: 240 s 4.6x4.6 22m n/a 21 1 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.72

1st Reset Response Time (s) 2nd Reset

Controller: .25/4/4

Full Pan: 80s St. State: STEADY STATE NOT REACHED PRIOR TO EXTINGUISHMENT
268 4 Cold Climate - 22 m Facility

Table 69. UV/IR response times corresponding to manual reset after steady state burning for JPtest fires conducted in 22 m high facility

PAN SIZE

(m) FACILITY HRR (MW) TEST No. DETECTOR DISTANCE FROM SOURCE CENTER (m)

0.3 xO.3 22m 0.1 9.14 10.7 12.2 13.7 15.2 16.8 18.3 21.3 30.5 45.7

1st Reset 2nd Reset

Controller:

Full Pan:

142.5 s 164.5 s .25/4/4 2sResponse Time (s)

St. State: 120 s

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

3.3

0.3 NR15.1 NRNR

NR

NR

NR

NR

NR

0.6x0.6 22m 0.9 10 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

1st Reset 2nd Reset

Controller:

Full Pan:

120 s 164.9 s .25/2/3

15 s

Response Time (s)

St. State: 120 s

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

18.8 0.3 NR

0.3

0.6x0.6 22m 0.8 11 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

1st Reset 2nd Reset

Controller:

Full Pan:

134.3 s 176.6

.25/2/3

15 s

Response Time (s)

St. State: 120 s

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

1.1

0.3 14.429.5

24.8

0.9x0.9 22m 1.7 12 21.3 24.4 25.9 27.4 30.5 33.5 36.6 39.6 42.7 45.7

1st Reset 2nd Reset

Controller:

Full Pan:

189.6 s 209.3 s

.25/2/3 20 s

Response Time (s)

St. State: 180 s

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3 0.30.3

0.3

0.3

0.3

0.3

0.3

0.8 0.80.3

0.3

1.2 X 1.2 22m 2.8 13 21.3 24,4 25.9 27.4 30.5 33.5 36.6 39,6 42.T 45;:7;

1st Reset 2nd Reset

Controller:

pull Pan:

122.6 s 137.6 s .25/4/4 30 sResponse Time (s)

St. State: 120 s

0.3

0.3

0.3

0.3

0.3

0.3

•0.3

0.3

0.3

0.3

0.3

0.3

0.3

0.3

1.6 0.31.6

1.8

1.6

2.1

3.0 X 3.0 22m 14.3 17 21.3 24.4 25.9 27.4 30.5 33.5 36,6 39.6 42.7 45.7

1st Reset 2nd Reset

Controller:

Full Pan:

276.9 s 293.3 s .25/4/4 50 s

Response Time (s) 0.3 0.3

0.3 0.40.3 0.4

0.3

0.3

0.3 0.40.3 0.4

0.3 0.40.3 0.40.3 0.4

ST. STATE: 270 s

0.3 0.4

Previous studies by the Factory Mutual Engineering Corporation indicate that the skin of aircraft

fuselages will fail after 45 s of spill fire exposure [30]. Unfortunately, those data do not represent the

decreased resistance to fire of today's typical composite material (i.e., stealth aircraft). Nevertheless,

45 s was the maximum response time used in determining threshold response distances. Further studies on the effect of fire exposure on aircraft skin will help determine acceptable response times of optical

detectors. An additional element which must be considered in determining the acceptable response

time is the time required to achieve foam coverage of the designated floor areas after the fire has been

detected.

The controller settings of combination UV/IR detector varies with respect to test number. The

controller setting variations for similar sized fires was done on a very limited basis in the 22 m high
4 Cold Climate - 22 M Facility 269

facility. However, Figures 132 and 133 graphically illustrate the effects on the 0.3 m x 0.3 m and

0.9 m X 0.9 m pan fires respectively. Figure 132 clearly shows the detectors in test 9 with a setting of

0.25/4/4, failed to respond in the 5 s, 10 s, and 20 s time intervals. The detectors in tests 1 and 2, with

a setting of 0.25/2/3 responded in all selected times. Where the detectors in test 9 (i.e., 0.25/4/4) do

respond at 30 s and 45 s, the threshold response distances are 27 % to 46 % shorter than they are in

tests 1 and 2 (i.e., 0.25/2/3).

Maximum Response Distances

The maximum response distances for optical flame detectors for the tests conducted in the 22 m facility were determined to be the maximum distance at which a detector responded without respect to the

selected response times. Since detector response was measured at three fire events, the time at which

the maximum response distance was reached is represented for each stage of fire growth. The

maximum response distances are presented in Table 71. The effect of different controller sensitivity

settings on the maximum response distance was studied for the 0.3 m x 0.3 m and 0.9 m x 0.9 m pan

fires. Figures 132 and 133 illustrate that the detectors having a controller setting of 0.25/4/4 cannot be

expected to respond within 45 s when placed beyond 12.2 m for the 0.3 m x 0.3 m pan fire and 36.6 m

for the 0.9 m x 0.9 m pan fire respectively.

Predicted Response of Unitized UV/IR Optical Flame Detectors.

The researchers from Detector Electronics Corporation were asked to take the acmal raw counts per

second data acquired from the fire tests and mathematically predict the response of unitized optical

flame detectors and compare them to the responses of the controller based detectors. This analysis was

performed for responses from ignition during a select time interval.
270 4 Cold Climate - 22 m Facility

Table 70. UV/IR detector response threshold distances

all test fires conducted in 22 m high facility,

limited by hangar arrangement.

(m) at selected times after steady state for

Note: maximum distance (45.7 m)

TEST HRRfPANSIZE) CONTROLLER FUEL

SELECTED TIMES

1 0.1 MW (0.3 m X 0.3 m) 0.25/2/3 •JP-5

5 s

18.3

10 s

18.3

zu s

18.3

.)U s

18.3

45 s

18.3 2 1 MW <^0 3 m X 3 ni~t 25/2/3 JP-5 18.3 21.3 21.3 21.3 21.3

9 0.2 MW (0.3 m X 0.3 m) 0.25/4/4 JP-8 15.2 15.2 15.2 15.2 15.2

3 0.9 MW (0.6 mx 0.6 m) 0.25/2/3 JP-5 36.6 45.7 45.7 45.7 45.7

4 0.8 MW (0.6 mx 0.6 m) 0.25/2/3 JP-5 45.7 45.7 45.7 45.7 45.7

10 0.6 MW (0.6 mx 0.6 m) 0.25/2/3 JP-8 39.6 39.6 39.6 42.7 42.7

11 0.8 MW (0.6 mx 0.6 m) 0.25/2/3 JP-8 39.6 39.6 42.7 45.7 45.7

5 1.7 MW (0.9 mx 0.9 m) 0.25/2/3 JP-5 45.7 45.7 45.7 45.7 45.7

6 1.4 MW (0.9 mx 0.9 m) 0.25/4/4 JP-5 36.6 36.6 45.7 45.7 45.7

12 1.6 MW (0.9 mx 0.9 m) 0.25/2/3 JP-8 45.7 45.7 45.7 45.7 45.7

7 2.8MW(1.2mx 1.2 m) 0.25/4/4 JP-5 45.7 45.7 45.7 45.7 45.7

13

18

2.7 MW (1.2 mx 1.2 m)

4.9MW(2.0mDia.)

0.25/4/4

0.25/4/4

JP-8

JP-5

45.7

45.7

45.7

45.7

45.7

45.7

45.7 45.745.7

45.7

14 7.9 MW (2.5 m Dia.) 0.25/4/4 JP-5 45.7 45.7 45.7 45.7 45.7

16 7.0MW(2.5mDia.) 0.25/4/4 JP-5 36.6 36.6 36.6 36.6 36.6

19 9.1 MW (2.5 m Dia.) 0.25/4/4 JP-5 45.7 45,7 45.7 45.7 45.7

15 15.7 MW (3.0 mx 3.0 m) 0.25/4/4 JP-5 N/A" N/A" N/A" N/A" N/A"

20 14.6 MW (3.0 mx 3.0 m) 0.25/4/4 JP-5 45.7 45.7 45.7 45.7 45.7

17 14.3 MW (3.0 mx 3.0 m) 0.25/4/4 JP-8 45.7 45.7 45.7 45.7 45.7

21 33MW(4.6mx4.6m) 0.25/4/4 JP-5 N/A' N/A'^ N/A' N/A*^ N/A'

N/A" - No resets prior to steady state N/A'' - No resets after steady state N/A' - Fire Extinguished prior to steady state.
4 Cold Climate - 22 m Facility 271

Table 71. UV/IR maximum response distances and response times from selected events for all test fires conducted in 22 m high facility

TEST HRR (PAN SIZE, m) FUEL

CONTROLLER

SETTING

THRESHOLD

DETECTOR

MAXIMUM

DETECTOR

PLACEMENT

(m)

RESPONSE TIMES (s)

;; # DISTANCE

(ra) IGNITION FULL

PAN

ST. STATE

1 0.09 MW (0.3 X 0.3) JP-5 .25/2/3 16.8 45.7 28.8 0.8 0.3 2 0.08 MW (0.3x0.3) JP-5 .25/2/3 18.3 45.7 39.8 2.3 2.1 9 0.18 MW (0.3x0.3) JP-8 .25/4/4 15.2 45.7 74.6 1.3 3.3

3 0.93 MW (0.6 X 0.6) JP-5 .25/2/3 36.6 45.7 49.5 4.1 4.6 4 0.77 MW (0.6 X 0.6) JP-5 .25/2/3 39.6 45.7 59.1 6.8 1.5 10 0.6 MW (0.6 X 0.6) JP-8 .25/2/3 36.6 45,7 36.2 3.8 0.3

11 0.77 MW (0.6 X 0.6) JP-8 .25/2/3 42.7 45.7 54 N/A' 14.4

5 1.69 MW (0.9x0.9) JP-5 .25/2/3 45.7 45 7 98 1 '\ 1 8

6 1.39 MW (0.9x0.9) JP-5 .25/4/4 45.7 45.7 56.3 4.6 17.1

12 1.62 MW (0.9x0.9) JP-8 .25/2/3 45.7 45.7 35.1 17.4 0.3 7 2.81 MW(1.2x 1.2) JP-5 .25/4/4 45.7 45.7 53.7 0.5 4.6

13 2.65 MW (1.2 X 1.2) JP-8 .25/4/4 45.7 45.7 49.5 8.3 2.1

18 4.92 MW (2.0 Dia.) JP-5 .25/4/4 45.7 45.7 54.9 3.1 0.5

14 7.86 MW (2.5 Dia.) JP-5 .25/4/4 45.7 45.7 46.3 0.3 0.3

16 7.0 MW (2.5 Dia.) JP-5 .25/4/4 36.6 45.7 35.4 0.3 3.1 19 9.13 MW (2.5 Dia.) JP-5 .25/4/4 45.7 45.7 49.8 1.1 0.3

15 15.73 MW (3.0x3.0) JP-5 .25/4/4 45.7 45.7 40.7 0.3 N/A^

20 14.6 MW (3.0x3.0) JP-5 .25/4/4 45.7 45.7 44.1 0.3 0.3

17 14.3 MW (3.0x3.0) JP-8 .25/4/4 45.7 45.7 40.4 0.3 0.04 21

33 MW (4.6x4.6) JP-5 .25/4/4 MmMMmm:: 45.7 44.5 0.8 N/A'

NR - No detector response N/A" - No reset prior to steady state. N/A*" - No reset after steady state.

N/A'^ - Fire Extinguished prior to steady state.
272 4 Cold Climate - 22 m Facility

Bh Ph Pn

1-9 i-s i-s fO K^ t

r« r< Tt

V) V) in

r« N n e e e

^ ^ •^ a a a

n c« n

a. o. Q. a B a

fO K^ t^ e e e

M M H

S S a

f»» n m

e e e

* «t •» ^ ^ ^ s s s

9\ 00 00

H H H

H D

(ui) SHONVISIQ 3SN0dS3U QIOHSaUHl

V2

0)

)-( Im

-1—

>

C/5 0)

*-*

lO B

* d

6

m

d

Mn

n o

(U A o U c^ S »3 H

-o

w fO o s

H

U «5 u 0) m9 k-i U 73

(» 1

1

§

CO00 e

rV/IR

controller

settin

in

22m

high

facility.

W -^ T3

Figure

132.

Effect

of

conducte
4 Cold Climate - 22 m Facility 273

H

fiH

U

Eden

(ui) SHDNVlSia HSMOdSHH QlOHSHHHl

<u

e

OSd

ONd

(US

T3

(UO

o

c

03

o

ex

C/1 1)

i-i T3OXc/l (U

kH J=co

00

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-4-» >,

-t-t on o

n x;

iH Oi) C Si o

a S

Qi (N ^^ <N > e

i*- ^ a(1) o a

o

3

tji; C vt-i n

UJ o

COen

•—

(U

Ui
274 4 Cold Climate - 22 M Facility

4.4.6 Response of Line-Type Heat Detector

The line-type heat detector installed in the 22 m high facility provided continuous measurement of

ceiling temperature as a function of fire size. A description of the way the sensor was installed was

provided earlier in section 4, and the theory of its operation and characteristics was given in section 3. The following table and graphs describe how the linear sensor responded to various fire sizes. A

comparison to automatic sprinkler response and spot-type heat detector response is made. Also, a

linear heat detector is characterizing (for a high bay) space where there may be temperature

stratification in the upper layer.

Table 72 describes how the linear heat sensor responded to various fire sizes. The table shows fire parameters, the maximum ceiling temperature, maximum sensor temperature, and the time the sensor reached 57 °C (135 °F) and 79 °C (175 °F). These temperatures correspond to the activation

thresholds for spot-type heat detectors and intermediate range automatic sprinklers.

From Table 72 it is shown that for smaller test fires, 0.3 m x 0.3 m pan to 1.2mx 1.2m pan, the

maximum temperature at the center never exceeds 50 °C (122 °F). Likewise, the maximum sensor temperature does not exceed 37 °C (99 °F). Therefore, using criteria designed for spot-type heat

detector or automatic sprinkler response may not be appropriate for this sensor. Figure 134 shows the

response of the linear heat sensor along with the center thermocouple measurement for each of these

smaller test fires. Additional experiments were conducted using JP-8 aviation fuel in the smaller pan

sizes (tests 9-13). These tests were omitted from the table since the burning characteristics and heat

output were similar to the JP-5 fueled experiments.

For the larger JP-5 fires the maximum temperature at the ceiling ranged from 59 °C to 272 °C.

However, the maximum temperature recorded with the linear heat sensor ranged from 49 °C to 205 °C. Figures 135 and 136 show the comparison of ceiling temperature to linear heat sensor response for many of the larger fires. For example, test 14 used a 2.5 m diameter pan fueled with JP5. The maximum center temperature at 0.3 m below the ceiling reached 93 °C (199 °F). The linear

heat sensor reached a maximum temperature of 75 °C (167 °F) and surpassed the 57 °C threshold in

222 s. The time to reach this threshold is nearly 120 s slower than the time it took the first 57 °C spottype heat detector to alarm. In addition, intermediate range sprinklers (i.e., 79 °C, quick response)

activated at 262 s. The linear heat sensor in this case never reached the 79 °C threshold. Figure 137

shows the response times of spot-type heat detectors and automatic sprinklers with respect to the line- type heat detector response for this case.

In test 15, a 3.0 m x 3.0 m pan produced a maximum ceiling temperature of 170 °C (338 °F).

Whereas the linear heat sensor reached a maximum of 139 °C (282 °F). Spot-type heat detectors

began activating at 82 s and 79 °C QR sprinklers at 119 s. The linear heat sensor reached the 57 °C

threshold at 116 s and the 79 °C threshold at 171 s. This comparison is shown in Figure 138.

A comparison can be made between the center temperature profiles and line-type heat detector

response. The preceding figures show a marked difference in temperature between the center thermocouple and line-type heat detector. It is understood that the center thermocouple, within the

plume region, would indicate a higher temperature than thermocouples outside the plume region. The

linear heat sensor is within the plume region for only a small portion of its length.
4 Cold Climate - 22 m Facility

Table 72. Results of line-type heat detector response to test fires in 22 m high facility.

275

Test Information

Test

Number

1

2

3

4

5

6

7

8

14

15

16*

17 (JP-8)

18

19*

20

21

Pan Size

m

0.3x0.3

0.3x0.3

0.6x0.6

0.6x0.6

0.9x0.9

0.9x0.9

1.2x1.2

1.2x1.2

2.5 dia. 3.0x3.0

2.5 dia. 3.0x3.0

2.0 dia.

2.5 dia. 3.0x3.0

4.6x4.6

Fire Size

MW

0.1

0.1

0.9

0.8

1.7

1.4

2.8

n/a

7.9

15.7

7.0

14.3

4.9

9.1

14.6

33

Measured Temperatures and Response Times

Max. Ceiling

Temperature ^ °C, ±2

12

14

21

23

34

33

49

n/a

93

170

59

175

71

72

176

272

Max. Sensor

Temperature

°C, ±2

14

15

18

20

27

28

36

n/a

75

139

49

137

53

56

136

205

Time to 57 °C

s, ± 4

n/a

222

116

106

103

90

Time to 79 °C

s, ± 4

n/a

171

184

190

100

n/a

Open door test. Did not reach temperature threshold.

No data available.

Center thermocouple at 0.3 m below the ceiling.
276 4 Cold Climate - 22 m Facility

70

60

50

Oo2 40

3

TO

k_

0)Q.

E

I- 30

20 -

10 -

22 m High Facility

#1 - 0.3 m X 0.3 m pan, JP-5, Test 1 #2 - 0.6 m X 0.6 m pan, JP-5, Test 3 #3 - 0.9 m X 0.9 m pan, JP-5, Test 5 #4 - 1.2 m X 1.2 m pan, JP-5, Test 7

rJ ^J

t^^^^^\

\

A# - Center Thermocouple @ 0.3 m Below Ceiling

B# - Linear Heat Sensor Response

I

'

' '

I

' ' '

I 120 240 360

1

1 1 1

1

1 1 r 480 600 720

Time (s)

Figure 134. Comparison of line-type heat detector to center temperature for smaller fires conducted

in 22 m high facility.
4 Cold Climate - 22 m Facility 277

220

200 -

180

160

140

p

^ 120

4-< (0

L_(UI" 100

h80

60

40

20 -

22 m High Facility

#1 - 2.5 m dia. pan, JP-5, Test 14 #2 - 3.0 m X 3.0 m pan, JP-5, Test 15 #3 - 2.0 m dia. pan, JP-5, Test 18

^^j^.^ _ A# . Center Thermocouple @ 0.3 m Below Ceiling

B# - Linear Heat Sensor Response

"T" 120 240 360

Time (s)

480 600 720

Figure 135. Line-type heat detector response and center temperature profiles for test fires using 2.0

m dia., 2.5 m dia., and 3.0 m x 3.0 m pans (tests 14, 15, 18).
278 4 Cold Climate - 22 m Facility

300

280 -

260 -

240 -

220 -

200

180

O

^ 160 H

4—» K 140

E" 120

100

80

60

40 H

20

22 m High Facility

#1 - 3.0 m X 3.0 m pan, JP-5, Test 17 #2 - 3.0 m X 3.0 m pan, JP-5, Test 20

#3 - 4,6 m X 4.6 m pan, JP-5, Test 21

Jjjy A# - Center Thermocouple @ 0.3 m Below Ceiling

B# - Linear Heat Sensor Response

n 1 1 1 r n 1

1 1 1 1 1

1 1 1

1

1

1

i 1 1 1 r 120 240 360 480

Time (s)

600 720

Figure 136. Line-type heat detector response and center temperature profiles for tests using 3.0 m x

3.0 m and 4.6 m x 4.6 m pans (tests 17, 20, 21).
4 Cold Climate - 22 m Facility 279

120

120

100 -

80 - Oo

2

0)Q.

E

60

40

20

240

\ 360

\ 480

a b c d e

II /I

/ I g 1

Center Thermocouple @ 0.3 m Below Ceiling

Linear Heat Sensor Response

120 240

\ ' ' ' 360 480

Time (s)

Events

57.2 °C (135 T) Spot-type heat detectors a - 3.0 m S, 94 s b - 3.0 m W, 1 1 1 s c-3.0mN, 119s

d-3.0mE, 128 s e-6.1 mN&W, 141 s f-6.1 mS, 181 s g-6.1 m E, 236 s

Automatic Sprinklers

1 -S1F, 79°CQRdry, 262 s 2-S1B, 79°CQR, 361 s 3 - CF, 79 °C QR dry, 366 s 4 - W1 F, 79 °C QR dry, 480 s

Figure 137. Comparison of spot-type heat detectors and automatic sprinkler activation to line-type

heat detector for 2.5 m dia. test fire (test 14).
280 4 Cold Climate - 22 m Facility

120 240 360 480

200

180 -

160

140 -

120 Oo

I 100

0)Q.

§ 80 H

60

40

20

a b cd e,1 2

/

/

''^^

79.4 °C (175 °F)

57.2 °C (135 °F)

Center Thermocouple @ 0.3 m Below Ceiling

Linear Heat Sensor Response

"T 1 r 120 240

Time (s)

—

' ' '—

360 480

Events

57.2 "C (135 "F) Spot-type heat detectors

a - 3.0 m S, 82 s b - 3.0 m N/W/E, 90 s c-6.1 mN/S, 98 s d-6.1 mE/W, 102 s e-9.1 mE/W, 119 s

Automatic Sprinklers

1 - SI, S1F, NIB, E1F, 79 °C QR dry, 119 s 2 - CB, CG, 79 °C QR, (123 to 127)s

CG, 93=CQR, 127 s 3-CH, 79°CSR,220s

4-W5B, S1E, S1A, CE

141 °CQR, (314to338)s

5 -SID, 141 "CSRLINK

Figure 138. Comparison of spot-type heat detectors and automatic sprinkler activation to line-type

detector for 3.0 m x 3.0 m pan fire (test 15).
4 Cold Climate - 22 M Facility 281

Since this sensor was installed along the curvature of the hangar ceiling, if temperature stratification occurred during an experiment, portions of the sensor would be at different temperamres. The sensor measures a weighted average over its entire length. Therefore, a temperamre gradient will have a dramatic effect on the overall output. A simple example is shown of how temperature gradients can

effect the output of this type of sensor when installed along the curved portion of a ceiling.

Temperamre measurements are made at various points along the ceiling. Figure 139 shows an example

configuration. The relationship between temperature and sensor resistance is defined by;

/? = C,

(T

where R is the sensor resistance, T is the temperature (°F), and C,, C2, and C3 are constants. From the

figure, each 3 m section is defined by an average temperamre along that portion. This is similar to the

actual layout of temperature measurement points in the 22 m high facility. Each 3 m section of sensor

has a corresponding resistance, R^, based on the temperature of that zone. The resistance is calculated

for each 3 m section and then summed using the relationship of parallel resistors. Once the total resistance has been calculated, the resistance for the entire length of sensor is found to be 2.52 Mfi by

multiplying by the total length, 21m. By solving the above equation for T, the resuhing temperamre

output of the sensor can be computed.

ln(/? /C,) 1 -' T — r ^ sensor 1 ^ ^ - sensor ^ ^ y~, ^

For the above example, the calculations indicate that T^^^^x is equal to 27.3 °C.

A similar method was used to analyze the data from the acmal fire tests. Thermocouple measurements were used to determine the average temperature over the center portion of the linear heat sensor. By

assuming that the temperature "zones" were approximately uniform across the ceiling, perpendicular to the curvature, an estimate of the overall sensor temperature was found. The calculations were carried out for test 14 and 15. Figure 140 describes the comparison between actual sensor response and

computed sensor response. The computed temperature response of the linear heat sensor is similar to but higher than the measured response. This information may provide guidance on how the sensor should be installed in a space with a similar curved roof strucmre. Recalling that the roof structure of

the 15 m high facility was relatively flat, the response of the linear heat detector closely resembled

acmal temperature measurements, which were closer to uniform in the layer where the linear detector was installed.

The ability to predict the response of this type of sensor allows one to anticipate how various ceiling

configurations will affect the detector's performance. Based on calculated temperature profiles from a

fire model, an alarm point value and temperature response characteristics for this type of sensor can be

evaluated.
282 4 Cold Climate - 22 m Facility

21 m

Figure 139. Example configuration of linear heat detector installation in a facility with a curved

roof
4 Cold Climate - 22 m Facility 283

lilU - Actual Sensor Response Test 14 - 2.5 m dia. pan, JP-5

- " -- Computed Sensor Response

Center Thermocouple

100 -

o 80 - ^^/—'^^

(1)

- — —-~-.__-"'"' , -^

li. ^ —— —

-J

-^ ^ —

60 - / ^ . -^

I- / -^

<Dn _ ^ '-' F / /

0) 40 -

20 -

ly

- ~~-~'~y^

n

U 1

' 1'

1

' .1 1 ' 1 120 240 360

Time (s)

480 600

£.\JVJ Actual Sensor Response

Test 15 - 3.0 m X 3.0 m pan, JP-5 180 - Computed Sensor Response

160 -

Center Thermocouple

oo

140 -

120 -

100 -

. .- _^ ^'^

QiQ.

E

0) H

80 -

60 -

/ /'^ y

• / y

/ / /

40 -

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- 1

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'

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480 600

Figure 140. Comparison of measured line-type heat detector temperature to computed values for 2.5 m dia. and 3.0 m x 3.0 m test fires in 22 m high facility.

285

APPLICATIONS OF FIRE MODELS

The computational fluid dynamics model FLOWSD [29] was used prior to conducting the full-scale fire

tests to predict the size fires necessary to activate the sprinklers. These calculations (discussed in sections 3 and 4) were also useful for estimating the range of conditions that would exist in the vicinity

of the fire. Rather than a detailed field model such as FL0W3D, fire protection engineers more

typically use simple correlations or zone models for guidance in the analysis of fire protection strategies

for structures. However, the performance of fire correlations and zone fire models have not been

extensively tested at the heights studied in these experiments.

The purpose of this section is to look at the capabilities of some of these models and assess their ability to predict maximum ceiling temperature and sprinkler activation. The models considered include the

plume correlation of Heskestad [1 1], DETACT [12], and FPEtool [13]. All three models allow for the

calculation of peak ceiling temperature over plume center and both DETACT and FPEtool provide

ceiling jet models for sprinkler activation predictions. The sprinkler activation model in DETACT is based on the ceiling jet correlation of Alpert [14]. This correlation is also included in FPEtool. A

second sprinkler detection algorithm is included in the Fire Simulator part of FPEtool and simulates the

impact of the presence of an upper layer on the plume entrainment. Details of each of these models

may be found in the cited references. The ceiling plume temperature model in FPEtool is based on the

correlation developed by Alpert and Ward [15].

In order to simulate plume centerline temperatures, the estimated steady state heat release rate for each

test was used to represent the fire. These heat release rates were determined using load cell measurements as discussed in section 3.3 with the exception of tests 6b and 7 in Hawaii where a measurement of fuel consumption during the fire yielded an estimated average heat release rate for the

fire. The fire was assumed to grow linearly from zero at the start of each test and reach its steady-state

value 60 s after full pan involvement of the fire which was determined using visual observation. A 30

% radiative fraction was used to account for heat lost by radiation from the fire to the walls.

The ceiling heights used for the calculations were 14.9 m and 22 m. All the fire models simulate

smooth, flat ceiling geometry, hence the impact of large strucmral members found at the ceiling in both hangars and the effect of the curved ceiling in the 22 m hangar could not be included in the

calculations.

A comparison of the measured plume centerline temperature and the predictions of the correlation and

models are presented in Figures 141 and 142. The uncertainty in the thermocouple measurements are represented by the brackets on the experimental Tmax bars. For the Hawaii tests, both the ceiling

plume temperature model in FPEtool and Heskestad's plume theory provided good predictive results when compared with the measurements. Only for test 6b, with a heat release rate of 7.7 MW, did the

predictions significantly disagree with measurements. For this test, the heat release rate was based on

the volume of fuel burned and hence the discrepancy with predictions may be a result of an incorrect

heat release rate rather than a problem with the models.

The Iceland fire tests provided a larger data base to do model comparisons. Tests 1- 7 and 14, 15. 18,

and 20 were closed door JP-5 tests. Tests 16 and 19 were open door JP-5 tests and tests 9-13 and 18 were closed door JP-8 tests. For the closed door JP-5 tests, the models tended to over predict the
286 5 Applications of Fire Models

160

STmax (Act) FPETOOL

DDETACT

hesk.

Test

Figure 141. Hawaii Plume Centerline Temperatures.
5 Applications of Fire Models 287

Iceland Plume Temperature

160

Figure 142. Iceland Plume Centerline Temperatures.
288 5 Applications OF Fire Models

ceiling temperature for the smaller fires but as the fire size increased, the models substantially under

predicted the observed ceiling temperature. Model predictions for the open door JP-5 fire were closer

to the measured values but the lower ceiling temperatures produced by the fires were due to wind

effects and since none of the models include wind interactions, any agreement between model

predictions and experimental results should be regarded as fortunate. The JP-8 closed door fire tests followed the same trend as the JP-5 closed door fire tests in that the models provided good predictive

results for the small fires but substantially under predicted the ceiling temperature for the large fires.

There are several possible reasons for the model failure in the large fires. The first reason is that the

radiative fraction drops significantly for large pan fires [16] due to the fire volume becoming optically

thick. The drop in radiative loss increases the convective heat release rate and would boost the model

predictions above the temperatures predicted using the 30 % radiative fraction. Inclusion of this effect would change model predictions of ceiling temperamre for the largest fires by about 12 °C which is not

sufficient to explain the temperature gap between model predictions and experimental results for the

large fires. A second explanation would be that due to the extremely high flame heights produced by

the large fires, the measurements done at the ceiling were not sufficiently far out of the combustion

region for the plume theories to be valid. Flame heights for these experiments are given in table 48

and with the possible exception of test 21 where temperature spikes were observed at the ceiling, the

observed flame height was substantially less than the ceiling height. A final reason may lie with the

plume correlations. The data sets used to derive the correlations typically favor smaller fires and are based on data from unconfined ceiling experiments. These correlations, which do not include the

impact of a smoke layer, are not adequate for large fires where a hot, deep, smoke layer develops

quickly.

Of the three models used to predict ceiling temperature, the ceiling plume temperature model in FPEtool predicted the highest ceiling temperatures and DETACT predicted the lowest ceiling

temperatures. This difference is due to the conservative design of both models. The correlation used in FPEtool is designed to be high to provide structural damage estimates while the DETACT correlation is designed to give lower temperatures for sprinkler activation. None of the models gave accurate temperature predictions for experiments with ceiling temperatures in excess of 79 °C.

To investigate model predictions of sprinkler activation, FPEtool was used to calculate sprinkler

activation for the test fires in Hawaii and Iceland where sprinkler activation was observed. Both the

ceiling jet correlation of Alpert and the ceiling jet correlation in Fire Simulator were included in the

comparison. Alpert's correlation is designed for smooth, unconfined ceilings while the correlation in Fire Simulator uses a smooth ceiling correlation but includes the impact of a growing layer on the

ceiling jet temperature.

Tables 73 and 74 present the results of this analysis for the 15 m and 22 m facilities. In the tables,

"Alpert" refers to Albert's ceiling jet model which is available in both DETACT and FPEtool.

"FPEtool F.S." refers to Fire Simulator which accounts for entrainment changes in the plume due to layer formation. The average activation time for the quick response sprinklers are tabulated in the row

labeled "Actual." Entries containing asterisks indicate that one or more sprinklers did not activate

during the experiment. Albert's correlation was computed using FPEtool but similar results would be

obtained using DETACT. The fire was modeled using a heat release rate that started at zero and

linearly grew to its steady state value by 60 s after full pan involvement. The radiative fraction used

for the computation was 0.3. The sprinklers simulated had an activation temperature of 79 °C and a
5 Applications OF Fire Models 289

RTI of 35 (m s)'^

The activation times predicted by both ceiling jet models for tests 5 and 7 are much too short compared

to the measured response times. A major reason for this discrepancy is probably due to the changing

location of the plume center. Typically, the plume center, which is the hottest part of the plume moves

around the center of the ceiling as discussed in section 3.3.2. As the plume moves or the fire pulsates,

the local temperature at the thermocouple will vary. These experiments were designed to be threshold

experiments for sprinkler activation. When the temperature at the sprinkler head is marginally above

the activation temperature, the heating rate, which is proportional to the temperature difference

between the gas and the thermal element, is not as fast as would be calculated using computer analysis

which does not include plume movement and intermittent temperatures. These models assume a steady

temperature above the activation temperature. An example of this effect can be found in Figure 41

where the local gas temperature fluctuates substantially prior to the activation of the sprinkler. Other

effects which impact the accuracy of the model predictions include the uncertamty in the RTI and

activation temperature of the sprinkler head and the effect of the ceiling structures on the hot gas flow.

For the larger fire, test 6b, the model provided good predictions for the sprinkler located on the center

line and for the one at 3.0 m. Alpert's model failed to predict sprinkler activations further from the

plume centerline which may be a failing of the ceiling jet algorithm or the result of plume movement.

FPEtool F.S. predicted much quicker activation times for the sprinklers at 6. 1 m and 8.5 m and also

predicted activation at 11.6 m even though no sprinkler activated at this distance.

For the 22 m hangar tests, Alpert's ceiling jet model predicted sprinkler activation only for the 33 MW

fire while quick response sprinklers were activated for a fire size as small as 7.9 MW. The failure of

this model is understandable as the smoke layer develops rapidly in these experiments. The presence of

the smoke layer will produce ceiling jet temperatures in excess of those predicted using an algorithm

which does not include layer formation.

FPEtool F.S. results were obtained using fire simulator in FPEtool. Modeling of the 22 m hangar was

done by assuming that the ceiling was flat and located 22.3 m above the floor. The draft curtained

space had a ceiling area of 676 m^. A leak of length 45.7 m with a height of 0. 1 m above the floor was

used to simulate door leakage. Since fire simulator includes the effects of the layer on the plume and

ceiling jet, a second modeling calculation, designated (2) in the table, was done using test 15 to investigate the sensitivity of layer depth on the calculation. In this second calculation, the draft curtain was simulated as two doors, each of height 13.4 m and length 45.7 m. This calculation should keep the

layer depth to just below the draft curtain which will be a smaller depth than observed experimentally.

The predictions for the 14 to 33 MW fires using fire simulator were very close to the measured values

for distances of 6.1 m or less. Fire simulator consistently predicted values that were less than

measured, but this is understandable based on the fact that travel time of the smoke from the fire to the

detectors is ignored in the calculations. The travel times would add anywhere from 5 s to 30 s to the

calculated results depending on radial position. For distances beyond 6.1m, the agreement is not good but at these radial distances, the curved roof begins to be important which violates the physics of

the model. FPEtool did not predict the sprinkler activations correctly in test 14. This test is a threshold test which means that the sprinklers are barely able to activate during the test. To predict

threshold activation correctly is beyond the current accuracy of the correlations in these models and

requires knowing the RTI and activation temperature of the sprinkler head accurately.
290 5 Applications of Fire Models

FPEtool contains an atrium model which provides the smoke temperature for a high space which is ventilated at a rate equal to the plume flow to the ceiling. These experiments did not provide ceiling

ventilation and so the application of this model is not valid for these experiments but since fire protection engineers may be tempted to use the model, two modeling calculations were made to indicate how badly the model fails when used improperly. The model predicted a 11 °C temperature

rise in the smoke layer for the 33 MW fire in Iceland and a 4 °C temperamre rise for the 7.8 MW fire in Hawaii. The observed temperature rise near the ceiling for both these experiments far exceeded the

predicted values which is expected since the measurements near the ceiling are in the ceiling jet and the

model is predicting smoke temperatures in a well ventilated space and not ceiling jet temperatures.

Table 73. Sprinkler Analysis in 15 m Facility

Test #5 - 2.0 m diameter JP-5, 6.8 MW

Radius Om 3m 6.1 m 8.5 m /9.1m 11.6m

Alpert 79 s 88 s NR NR NR

FPEtool F.S. 80s 85 s 120 s 153 /165 s NR

Actual 182 s 186 s 297 s NR NR

Test #6b - 2.5 m diameter JP-5, 7.7 MW

Alpert 76 s 84 s NR NR NR

FPEtool F.S. 76 s 81 s 109 s 122 s/ 132 s 152 s

Actual 85 s 112s 186 s 327 s NR

Test #7 - 2.0 m diameter JP-5, 5.6 MW

Alpert 87 s 98 s NR NR NR

FPEtool F.S. 89 s 95 s NR NR NR

Acmal 397 s 479 s NR NR NR
5 Applications of Fire Models 291

Table 74. Sprinkler Analysis in 22 m Facility

Test # 14 2.5 m diameter JP-5 7.9 MW

Radius 0.0 m 3.0 m 6.1 m 9.1 m 12.2 m 15.2 m

Alpert NR NR NR NR NR NR

FPEtool

F.S.

139 s 139 s 162 s 186 s 203 s 215 s

Actual 463 s 438 s* NR NR NR NR

Test #15 3.0 m X 3.0 m JP-5 15.7 MW

Alpert NR NR NR NR NR NR

FPEtool

F.S. (1)

92 s 92 s 105 s 116s 124 s 129 s

FPEtool

F.S. (2)

98 s 98 s 116 s 132 s 147 s 159 s

Actual 121 s 160 s* 194 s 239 s 300 s 352 s

Test #17 3.0 m X 3.0 m JP-8 14.3 MW

Alpert NR NR NR NR NR NR

FPEtool

F.S.

90s 90s 103 s 114 s 122 s 128 s

Actual 112 s 112 s* 137 s* NR 355 s* 355 s *

Test #20 3.0 x 3.0 m JP-5 14.6 MW

Alpert NR NR NR NR NR NR

FPEtool

F.S.

98 s 98 s 111 s 123 s 131 s 137 s

Actual 117 s 116 s* 156 s* 262 s* 405 s* NR

Test #21 4.6 m x 4.6 m JP-5 33 MW

Alpert 92 s 92 s 135 s NR NR NR

FPEtool 62 s 62 s 72 s 80s 86 s 90s

Actual 91 s 88 s* 95 s* 190 s* 123 s 132 s*

293

6 CONCLUSIONS AND RECOMMENDATIONS

6.1 Observations on Behavior of Fires

6.1.1 Experimental

Because a growing fire may damage aircraft adjacent to the site of ignition, it is important to evaluate

how the heat is released from realistic size fires. This test program provided a unique opportunity to study the behavior ofjet fuel pool fires in large confined spaces under environmentally controlled

conditions. Fire sizes ranged from 0.3 m x 0.3 m to 4.6 m x 4.6 m, releasing heat at rates between

100 kW and 33 MW. Two different jet fuels (JP-5 and JP-8) were used, and the hangar geometry was

varied in a systemafic way to study the impact of ceiling height (15 m and 22 m), ceiling shape (flat and

barrel vaulted), draft curtains (with and without) and cross flow created by large open doors.

Reduced scale experiments conducted at NIST examined the heat release rates of JP-4, JP-5, and JP-8.

While JP-5 and JP-8 are the primary fuels now used for military aircraft, existing fire protection

guidelines are based upon the threat posed by the fuel they have superseded, JP-4. The results from the cone calorimeter show that JP-4 burns at a rate nearly 25 % faster than both the JP-5 and JP-8 fuels. This

difference in burning rate is also seen in the large calorimeter experiments where a 1 .0 m diameter pan of

JP-4 produced heat release rates of 1 .9 MW, compared to 1 .35 MW and 1 .5 MW release rates for JP-5

and JP-8, respectively. The cone calorimeter, using 75 mm pans, produced enthalpy fluxes about five

times smaller, which is a result consistent with the literature [35].

The heat release rate from all full-scale test fires can be correlated with a single straight line with a slope

of about 1.6 MW/m^ (see, for example. Figure 98), and can be compared to enthalpy fluxes of

1.74 MW/m^ and 1.90 MW/m^ measured in 1.0 and 1.2 m diameter pans for JP-5 and JP-8, respectively,

at NIST. These results indicate that a common energy flux around 1 .7 MW/m-^ can be assumed for JP-5

and JP-8 fires as long as the pan is greater than 0.9 m^, independent of the ambient fuel temperature,

precise geometry of the room or fuel pan.

In the larger test fires, a significant amount of time was required to achieve full pan involvement.

Excluding the smallest pans, for which fire spread was faster, the average flame propagation rate (starting from ignition at a corner) is estimated to be 0.055 m/s ± 0.010 m/s for both JP-5 and JP-8. The

time to full pan involvement can then be found from t = (4A/Tr)'''Vv, with v chosen as 0.055 m/s.

From the temperature data collected and visual observations made during this test series, it is clear that no significant heat or smoke stratification occurred. The maximum temperature rise above ambient for

the JP-5 experiments ranged from 3 °C for the 0.3 m x 0.3 m pan to nearly 123 °C for the 2.5 m

diameter pan in the 15 m high Hawaiian hangar. For the 2.5 meter fire in Iceland, temperature rise was

81 °C above ambient. The ambient temperature itself (28 °C in Hawaii compared to 12 "C in Iceland) did not appear to be a significant factor in the behavior of the fires.

The data show that the use of draft curtains can improve the response time of sprinklers and heat

detectors significantly in these hangars. Draft curtains contained the heat which lessened the time for the

sprinklers to respond and increased the number of sprinkler heads activated within the fire area. Another

question answered by these experiments was whether the draft curtain completely filled before spilling
294 6 Conclusions AND Recommendations

over into the adjacent curtained areas. Temperatures were measured at intervals spanning the full depth

of the draft curtain including positions outside the draft curtain space. Based on these measurements and

visual observations of the larger fires, it is concluded that hot gases and smoke can flow under draft curtains and spill into adjacent spaces prior to filling the first draft curtain area. However, for the depths

of curtains used in these tests, this spillage does not detract significantly from the performance

enhancement provided by the curtains.

As expected, having the hangar doors open significantly affects the behavior of the fires. The 2.0 m

diameter pan fires conducted with hangar doors open resulted in severe plume lean and reduced

visibility. In some cases, the plume lean approached 80° from vertical, and those experiments had to be

terminated approximately two minutes into the test. A fire with the hangar doors open can seriously

increase the response time of detectors and sprinklers, threaten adjacent aircraft, reduce visibility, and

hamper firefighting operations.

The experimental data indicate the following parameters have the most impact on the behavior of the fire (in decreasing order of importance), and are most likely to affect detection strategies:

• fire size

• cross v^'inds (such as through large door openings)

• ceiling height

The presence of draft curtains has a significant effect on the movement of the ceiling jet, but not on the

fire itself nor on the properties at the plume centerline.

Parameters of lesser importance in determining the structure of the pool fire are the following:

fuel type (JP-5 vs. JP-8)

• pool shape (square vs. round)

• ambient temperature (12 °C vs. 28 "C)

6.1.2 Numerical Models

A limited number of field model calculations proved their worth for designing the proper fire size and

determining appropriate locations for some of the experimental measurements. No attempt was made to assess their ability to duplicate the experimental results.

Zone models and simple correlations were used to estimate plume and ceiling velocities and

temperatures, and to approximate sprinkler and detection response times in these experiments. These

models were not originally developed for high bay applications, nor are they currently used for designing

fire protection devices for hangars. Generally speaking, the predictions of the models did not correlate

well with the large jet fuel fires. Measured ceiling jet velocities were significantly different from the

estimated values. A comparison between the actual data and the output of these models shows that in their current form they should not be used to predict ceiling temperatures, detector response times,

sprinkler response times, nor structural damage from large fires, in aircraft hangars. This is due in part to the fact that most of these models are based on experiments conducted with smaller fires and/or lower

ceiling heights, where buoyancy-induced plume entrainment is considerably different from that encountered in the aircraft hangar test program.
6 Conclusions AND Recommendations 295

6.2 Summary of Detection System Performance

6.2.1 Detection of Smoke

Projected Beam Smoke Detectors

The present UL listings for projected beam smoke detectors are not suitable for detecting jet fuel fires in aircraft hangars. When tested using their listed settings, the dense smoke produced by jet fuel fires caused the projected beam detectors to activate a trouble alarm rather than a fire alarm. This is because

the light beam was quickly obscured by dense black smoke well before the detector could produce a fire alarm condition. These detectors use the trouble alarm state to indicate beam blockage (e.g., caused by

overhead cranes passing through the beam), a malfunction, or accumulation of dust or dirt on the

detector's optics. When initially set to a sensitivity less than that established under current UL listing

requirements, the projected beam detectors did activate fire alarm signals. However, the question

remains whether or not the revised settings will affect the trouble alarm ftmctions of these detectors.

The response of the projected beam smoke detectors with and without draft curtains was also

investigated during these experiments. These detectors, when located to monitor the smoke within the

draft curtain volume, respond faster to fires than when draft curtains are not used. Projected beam

detectors mounted below the lower edge of draft curtains, however, require an unacceptable amount of

time to respond.

Photoelectric Smoke Detectors

Although spot-type photoelectric smoke detectors would not typically be used in hangar applications, the

data collected can be helpful in determining proper spacing for this type of detector in similar high bay

spaces in which liquid fuels are present. The 0.3 m x 0.3 m fires did not produce enough smoke to activate any photoelectric smoke detectors. For the larger fires, ceiling curvature had no significant

effect on photoelectric detector response at 3.1 m and 6.1 m from the plume centerline. ft was found that

the detectors located 9.1 m from plume centerline compared to those spaced 3.0 m and 6.1 m from the

plume showed no significant difference in response times. Tests support that the spacing of photoelectric

smoke detectors of up to 12.2 m is acceptable (for these fast growing fires). This is contrary to the

present practice prescribed in NFPA 72 of reducing detector spacing with increased ceiling heights.

The presence of the draft curtains did not significantly affect the response time of these detectors, in contrast with the other detection devices, most likely because these detectors were installed within 0.3 m

of the ceiling (and thus in the ceiling jet).

The photoelectric smoke detectors sensed both JP-5 and JP-8 fires, and may be applied to other

combustible liquid fires that produce similar dense smoke. The measured response times for JP-5 fires were generally faster than for JP-8 fires, but this may be affected as much by the variations among the

tests as to the different fuel compositions.

6.2.2 Detection of Heat

Spot-Type Heat Detectors
296 6 Conclusions AND Recommendations

Temperature settings and detector spacings are the primary issues of concern when selecting heat

detectors. Two temperature responses were investigated in these tests: 57 °C and 93 °C. As expected,

57 °C heat detectors performed significantly faster than the 93 °C detectors. None of the heat detectors

responded to any fires less than 3 MW. When placed outside the draft curtain in the 22 m high hangar, no 93 °C heat detectors responded in any of the tests including the 33 MW fire. In the open door tests, none of the 93 °C detectors responded even when placed within the draft curtain area. The data obtained

for the 2.0 m diameter pan fires in the 15 m hangar indicate that the 57 °C spot-type heat detectors

activated nearly twice as fast with draft curtains in place as without draft curtains. The response times

of 57 °C heat detectors in the 22 m facility took 3 times as long as those in the 15 m hangar.

Since these detectors were installed at approximately 3 m intervals, the question of how far to space

these detectors for reliable activation in a high bay space was answered. The response of the 57 °C heat

detectors in the 15 m high facility showed that detectors could be installed at a spacing of 12.2 m (40 ft) without adversely affecting response times. This finding is contrary to the current practice of reducing

detector spacing with increased ceiling heights.

A secondary issue related to the performance of this type of detector is the complexity of the ceiling

configuration (i.e., structural beams). For the tests conducted in the 15 m high facility, the configuration

of ceiling level structural beams had no significant effect on heat detector response times.

Rate-compensated heat detectors are the preferred spot-type heat detector, but temperature selection is

still critical. The 57 °C heat detectors may be appropriate in a cold climate such as Iceland or Alaska,

but generally will not be appropriate in most other climates due to the possibility of false alarms during warmer weather. The 93 °C heat detectors proved unsuitable because they took longer to respond than

the 79 °C quick response sprinklers. On a pre-action type system, it is important to open the sprinkler

alarm valve before a number of sprinklers have activated. With closed-head sprinkler systems, it is important to match the temperature rating of the heat detector as closely as possible to that of the

automatic sprinklers.

Linear Heat Detectors

A linear heat detector was installed with a spacing based on the manufacturer's recommendation. In a nominally flat ceiling, using the NFPA 72 spacing for the detectors at a maximum ceiling height of 9.1 m

(30 ft), the line type detector cable reached the listed temperature of the spot type heat detectors at roughly the same time the heat detector responded. The linear heat detector closely resembled the

temperature readings measured by the thermocouples, agreeing to within ±7 °C for all experiments in the flat 15 m high facility. In nearly all cases the linear heat detector reached the 79 °C threshold before

any sprinkler activated and reached the 57 °C threshold within ± 15 s of spot-type heat detector

activation.

Because this detector was tested in a temperature measurement mode only, no alarms were initiated. One would normally select an alarm setting from the calibration curve given for each sensor and perform

several large fire tests to see when the detector reaches a certain temperature. In many cases, such as new facilities and/or "clean" facilities, this practice is not feasible. However, based on the data collected

during these test fires, alarm settings could be determined by evaluating predicted ceiling temperatures

and choosing a temperature threshold. It is important to note that the existing fire models would first have to be validated using the data collected during these experiments. This temperature threshold
6 Conclusions AND Recommendations 297

would be well above ambient temperature fluctuations but yet below the temperature ratings for the

sprinkler system.

The use of line type heat detector cable in a curved roof application is not recommended. There is not

yet enough experience installing the detectors in these applications. The line-type heat detector cable

under the curved roof had a much longer response time than any of the spot type heat detectors, yielding

average upper layer temperatures that were far lower than the peak local temperatures.

6.2.3 Detection of Flame Radiation

The UV/IR optical flame detectors respond much faster to a growing spill fire than any other detection

method examined, and long before overhead sprinklers or heat detection systems. This indicates that

UV/IR-activated foam monitors (or a similar system) might extinguish a spill fire before the overhead

systems are even activated. However, appropriate performance criteria need to be established, and

problems associated with existing foam monitor designs need to be eliminated. Until now, optical flame

detectors have only been tested and listed for their response to steady state fire conditions. From a fire protection standpoint, it is more important to evaluate their response times from the point of ignition and

during fire growth.

Controller-based optical flame detectors offer a much greater flexibility in detector setting and responded

faster than the predicted responses of the unitized optical detectors. Optical flame detectors designed for

JP-4 fires are suited for JP-5 and JP-8 fires as well.

6.3 Summary of Sprinkler Activation Performance

The data collected in the fire experiments support the use of closed head sprinkler systems in aircraft

hangars. In arriving at this conclusion, four different closed head sprinkler design parameters were

investigated to determine their impact on the activation time in the 15 m and 22 m hangars: temperature

setting, response time, link design, and dry vs. wet installations. The temperature set point is, by far, the

most important characteristic of the sprinkler, followed by the RTI. The wet-pipe versus dry-pipe

sprinkler configurations had no significant effect on the sprinkler response time to a variety of fire sizes. However, any dry-pipe or pre-action sprinkler system will incur an additional time delay delivering

water from an alarm check valve.

The 79 °C quick response sprinkler heads proved to activate most effectively of all the sprinkler heads

tested in these large fire, high bay hangar tests. Closed head sprinklers using 79 °C quick response heads

could circumvent the problems associated with false activation of deluge systems, and may provide a

similar degree of protection. The primary reason is that by the time the fire is large enough to activate

closed head sprinklers (or spot-type detectors) at the ceiling, the plume is large enough to activate a number of sprinklers, provided draft curtains are in place. A comparison of quick response vs. standard

response sprinklers shows the quick response heads activated 1 .5 to 2.5 times faster than the standard

response heads.

Test fires conducted in the 15 m high facility revealed that none of the automatic sprinklers installed

activated for the fire sizes less than 2.8 MW. The smallest test fire to activate any installed automatic

sprinklers was the 2.0 m diameter pan with a heat release rate of approximately 6 MW. In addition.
298 6 Conclusions AND Recommendations

none of the 141 °C sprinklers installed activated during any of the experiments conducted in the 15 m

high facility. The smallest fire to activate sprinklers in the 22 m hangar was 7.9 MW. The sprinklers at the peak of the 22 m roof activated approximately 20% faster than those at the same radial distance but

lower than the peak. The smallest fires to activate the 93 °C and 141 °C sprinklers were, respectively,

13.3 MW and 15.1 MW in size. In the 2.5 m open door test, no sprinklers activated; however, the

duration of this test was considerably shorter.

Fire size affects both the number of sprinklers activated and their response times. The tests performed in the 1 5 m hangar also evaluated sprinkler response with and without draft curtains. The same fire size

tests were conducted in both situations. With the draft curtains in place, more sprinklers operated with

faster response times. The draft curtains also improved sprinkler response farther from the centerline of

the plume. Without the draft curtains in place, the hot gas layer was unable to accumulate sufficiently to activate the sprinklers in a reasonable time.

The use of 141 °C closed head sprinklers in hangars is not acceptable because of the large fire size

required to actuate these sprinklers in a short enough period of time. In the 22 m hangar, a 2.5 m

diameter pan fire with a heat release rate of approximately 7.9 MW did not activate any of the 141 °C

sprinklers for the duration of the test. A fire of this magnitude could easily damage adjacent aircraft.

6.4 Overall Conclusions and Specific Recommendations

It can be concluded that current fire detection and sprinkler activation design criteria for high bay aircraft

hangars are insufficient to assure the protection of aircraft adjacent to the point of ignition. However,

there exist alternative designs and detection technologies that could be adopted to provide a much earlier

indication that a hazardous fire is present, permitting suppression strategies to be applied more

effectively.

The results of the experiments conducted in this program and the conclusions drawn from the subsequent

analysis and modeling are supportive of the following specific recommendations:

• A systematic review of the fire codes for large and high bay spaces should be initiated. The

review should include methods for large scale testing of fire detection devices and means for

appropriate model validation.

• When the protection of adjacent aircraft is a design goal for hangar fire protection systems,

NFPA 409 will need to be revised.

• Sprinkler heads with 79 °C quick response elements should be used in all closed head sprinkler

systems protecting aircraft hangars.

• Where spot-type heat detectors are used in conjunction with pre-action type sprinkler systems,

rate-compensated heat detectors should be selected with activation temperatures closely matched

to automatic sprinkler heads.

• Spot-type detector spacing for jet fuel fires in high bay hangars can be increased beyond the

limitations presently suggested in NFPA 72 for hangars up to 22 m in height.
6 Conclusions AND Recommendations 299

Optical flame detectors should be used if one wants to detect a growing spill fire quickly.

However, additional research is needed to determine response time and placement criteria based

upon hangar geometry, type and composition of aircraft.

More research is needed to determine alarm set points for line-type heat detectors in hangars in nominally flat ceilings if test fires during installation are to be eliminated. Additional research is also needed for installation and spacing of line-type heat detectors in hangars whose ceilings are curved or with significant height variations.

If accurate sprinkler or detector response, ceiling temperatures, or structural damage predictions

are sought, current fire zone models should not be applied to high bay hangars without first accounting for the growing hot ceiling layer. The data generated in this study can be used as the

basis for validation prior to the use of improved fire zone models in assessing fire protection

strategies.

The data collected in these experiments should be compared against predictions from

computational fluid dynamic models as a way to build confidence in and extend the range of

applicability of the models. With further validation, these numerical models can be used to complement experience and testing when selecting fire detection options for aircraft hangars and

other high bay spaces, but no single model prediction should be the basis of design change.

301

REFERENCES

[I] Krasner, L., Chicarello, P., and Fitzgerald, P., "Fire Protection of Large Air Force Hangars,"

Air Force Weapons Laboratory, Kirtland AFB, Report AFWL-TR-74-23, July 1974.

[2] NFPA 16A, Standard for the Installation of Closed-Head Foam-Water Sprinkler Systems,

National Fire Codes, National Fire Protection Association, Quincy, MA, 1994.

[3] Notarianni, K. and Davis, W., The Use of Computer Models to Predict Temperature and

Smoke Movement in High Bay Spaces. NISTIR 5304, National Institute of Standards and

Technology, Gaithersburg, MD, 1993.

[4] Alpert, R.L. , Calculation of Response Time of Ceiling Mounted Fire Detectors, Fire

Technology, Volume 8 Number 3, August 1972.

[5] Military Specification: Turbine Fuel, Aviation, Grades JP-4, JP-5, and JP-5/JP-8 ST, MILT5624P, September, 1992.

[6] Military Specification: Turbine Fuel, Aviation, Kerosene Types, NATO F-34 (JP-8) and

NATO F-35, MIL-T-83133D, January, 1992.

[7] Babrauskas, V., Development of the Cone Calorimeter - A Bench-Scale Heat Release Rate

Apparatus Based on Oxygen Consumption, NBSIR 82-2611, November 1982.

[8] Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products

Using an Oxygen Consumption Calorimeter, ASTM E-1354, Annual Book of ASTM Standard,

Volume 4.07, American Society for Testing and Materials (1990).

[9] Babrauskas, V., Lawson, J.R., Walton, W.D., and Twilley, W.H., Upholstered Furniture Heat

Release Rates Measured with a Furniture Calorimeter, NBSIR 82-2604, Natl. Bur. Stand.

(U.S.), 1982.

[10] Affens, W. A., McLaren G. W., and Carhart, H. W.,.Flammability Properties of Hydrocarbon

Fuels, Part 4 - The Significance of Flash Point as an Indicator of the Flammability Hazard of

Hydrocarbon Fuels, NRL Report 7549, March, 1973.

[II] Heskestad, G., "Fire Plumes," in SFPE Handbook of Fire Protection Engineering, second

edition, P. J. Dinenno, editor, NFPA, Quincy, Mass., 1995.

[12] Evans, D. D., and Stroup, D. W., "Methods to Calculate the Response Time of Heat and

Smoke Detectors Installed Below Large Unobstructed Ceilings," Fire Tech. 22, 54 (1986).

[13] Deal, S., Technical Reference Guide for FPEtool, Version 3.2, NISTIR 5486-1, National

Institute of Standards and Technology, 1995.

[14] Alpert, R., L., "Calculation of Response Time of Ceiling-Mounted Fire Detectors," Fire, Tech.
302 7 References

8, 181 (1972).

[15] Alpert, R.L., and Ward, E. J., "Evaluating Unsprinklered Fire Hazards," SFPE Technology

Report 83-2, Society of Fire Protection Engineers, Boston, MA, 1983.

[16] Yang, J. C, Hamins, A., and Kashiwagi, T, Combust. Sci. and Tech. 96, 183 (1994).

[17] NFFA 409, "Standard on Aircraft Hangars," National Fire Codes, National Fire Protections

Association, Quincy, MA, 1995.

[18] NFPA 13, "Standard for the Installation of Sprinkler Systems," National Fire Codes, National

Fire Protections Association, Quincy, MA, 1994.

[19] Military Handbook 1008B, Fire Protection for Facilities Engineering, Design, and

Construction, Headquarters, Naval Facilities Engineering Command, Alexandria, VA 1994.

[20] NFPA 72, National Fire Alarm Code, National Fire Protections Association, Quincy, MA,

1993.

[21] UL 268, "Smoke Detectors for Fire Signaling Systems," Underwriters Laboratories Inc.,

Northbrook, IL, 1994.

[22] "Beam Smoke Detection Systems Installation Instructions," Detection Systems Inc., Fairport,

NY, 1993.

[23] "Principles of Long-range Beam Smoke Detection," Detection Systems Inc., Fairport, NY,

1994.

[24] Mechler, T., (personal correspondence with K. Notarianni), Detection Systems Inc., Fairport,

NY, March 29,1995.

[25] Alt, J., (personal correspondence with J. Gott), Detector Electronics, Bloomington, MN, June

27, 1995.

[26] Instruction Manual for 9090 Sensor (PN A8MSN2), Alison Control, Inc., Fairfield, NJ,

February 1995.

[27] Davis, W., and Cooper, L., "Estimating the Environment and the Response of Sprinkler Links

in Compartment Fires with Draft Curtains and Fusible Line-actuated Ceiling Vents - Part II: User Guide for the Computer Code LAVENT," NISTIR 89-4122, National Institute of

Standards and Technology, Gaithersburg, MD, August 1989.

[28] Evans, D. D., and Stroup, D. W., "Methods to Calculate the Response Time of Heat and

Smoke Detectors Installed Below Large Unobstructed Ceilings," Fire Tech. 22, 54 (1986).

[29] FL0W3D Release 3.2 : USER MANUAL, CFD Department, AEA Industrial Technology,

Harwell Laboratory, United Kingdom, October, 1992.
7 References 303

[30] Loss Prevention Data Sheet 7-93N, Loss Prevention Data, Factory Mutual Engineering

Corporation, Inc., Norwood, MA, March 1991.

[31] Alpert, R., Comb. Sci. and Tech. 11, 197 (1975).

[32] Moore, W.D., editor. National Fire Alarm Code Handbook, First Edition, National Fire

Protection Association, Quincy, MA, 1994.

[33] Zimmerman, C.E., Bukowski, R.W., O'Laughlin, R.J., Editors, Fire Alarm Signaling Systems

Handbook, First Edition, National Fire Protection Association, Quincy, MA, 1987.

[34] Eraser, B., (personal correspondence with J. Gott), Simplex Time Recorder Co., Gardner,

MA, June 14, 1995.

[35] Hottel, H.C., "Certain Laws Governing Diffusive Burning of Liquids," Fire Research

Abstracts and Reviews 7, p. 41 (1959).

305

APPENDIX

Wood Crib Fire Tests, 15 m High Facility

Two wood crib fire tests were conducted in the 15 m high facility (test numbers 9 and 10). The purpose

of the wood crib tests was to evaluate the response of a variety of fire detection devices and sprinklers to

fires involving ordinary combustibles in high spaces. The devices evaluated included photoelectric

smoke detectors, heat detectors, projected beam smoke detectors, ultraviolet/infrared optical flame

detectors, and quick and standard response sprinkler heads with various activation temperatures. In

addition, the maximum ceiling temperature and temperature rise above ambient were obtained from

thermocouples installed throughout the test area. General information regarding these tests is shown in Table 75. It is important to note that test 10 consisted of two separate wood cribs (i.e., crib numbers 2

and 3) stacked on top of each other with each crib having dimensions of 0.6 m x 0.6 m x 0.6 m. Both

tests were conducted without draft curtains in place. Furthermore, there was no load cell present during

these tests; therefore, the heat release rate was calculated by the following equation:

Q = Ah, X mf

where

Q is the heat release rate (kW)

Ah, is the convective heat of combustion of the crib material (kJ/kg)

mf is the fuel mass burning rate (kg/s).

The convective heat of combustion is a percentage of the total heat of combustion. The remaining

percentage is loss to the environment by radiation. The fuel mass burning rate was determined by:

mf=(4/D)m„Vp[l-(2Vpt/D)]

where

D is the stick thickness (m)

m^ is the initial crib mass (kg)

t is the time since ignition (s)

Vp is the fuel surface regression velocity (m/s).

The fuel surface regression velocity is given by:

Vp = 2.2xlO-'D-'''

Response ofPhotoelectric Smoke Detectors

The response times of the photoelectric smoke detectors for tests 9 and 10 are shown in Table 76. The

photoelectric detector installation parameters are discussed in section 3, along with locations of the

detectors. The spacing of detectors beyond 6.1 m (20 ft) from the source of the fire was slightly different

along the north/south axis than the east/west axis due to the location of the draft curtain. Although the

draft curtain was removed for test 7- 1 3 the detector locations were not changed.
306 Appendix

In test 9, only 5 of 17 detectors installed responded to the 0.6 m x 0.6 m x 0.6 m wood crib fire. The

average response times at 3.0 m (10 ft) and 6.1 m (20 ft) from the source were 52 s and 58 s respectively.

Figure 143 shows the comparison of response times versus detector location. The spacing of detectors

showed no significant difference in the response times of detectors located 6.1 m (20 ft) away compared

to those spaced 3.0 m (10 ft) away. This indicates that a detector spacing of 12.2 m (40 ft) would be

acceptable for detecting a 0.6 m x 0.6 m x 0.6 m wood crib fire in a 15 m high facility. This is contrary

to the present practice of reducing detector spacing in high bay areas. No detectors beyond 6.1 m (20 ft) from the source responded during this test.

In test 10, all 17 detectors installed responded within 159 s. The average response time of the detectors

located 3.0 m (10 ft) from the source was 58 s, compared to 78 s for the detectors located 6.1 m (20 ft) from the source. These two detector locations showed no significant difference in response times.

Again, this is contrary to the present practice of reducing detector spacing in high bay areas. Figure 144

shows the comparison of response times versus detector spacing.

Response ofHeat Detectors

The heat detector installation parameters and mounting locations are discussed in section 3. No heat

detectors in either test 9 or 10 responded to the wood crib fires. The detectors were fixed temperature,

rate-compensated heat detectors with a listed temperature of 57 °C (135 °F). The maximum ceiling

temperatures directly above the plume centerline were 52 °C (125.6 °F) for test 9 and 53 °C (127.4 °F)

for test 10.

Response ofProjected Beam Smoke Detectors

The projected beam smoke detector installation parameters and mounting locations are described in section 3. The detectors were programmed with different settings (i.e., alarm sensitivity and alarm

window), some of which were outside their UL listing. The alarm sensitivity setting, which ranges

from 20 % to 70 %, represents a decrease in signal strength. The alarm window setting is the time the

signal must remain below the preset sensitivity level before an alarm is generated. The UL approved

alarm window setting is 30 s which is based on ordinary combustible fire loads. In the two wood crib

tests, there were three different alarm window settings used (5 s, 10 s, and 30 s) to determine the

difference in response of the projected beam detectors with shorter alarm windows. The projected beam

detector response times for tests 9 and 10 are shown in Table 77.

In test 9, all three detectors at the highest elevation (i.e., 0.3 m below the ceiling) responded with an

average response time of 80 s. The three detectors at the middle elevation (i.e., 1 .8 m below the ceiling)

did not respond. Of the three detectors at the lowest elevation (i.e., 2.7 m below the ceiling) only the center detector activated, with a response time of 46 s. It is important to note that this detector was

positioned directly in the fire plume.

In test 10, the average response time for the three detectors at the highest elevation was 124 s. Only 2 of

3 detectors located at the middle elevation activated, with a response time exceeding 560 s. Of the three

detectors located at the lowest elevation, only the center detector activated, with a response time of 41 s. Again, it is important to note that this detector was positioned directly in the fire plume.
Appendix 307

Table 75. General test information, wood crib experiments in 15 m high facility

Test

i Number

Crib

Number Material Dimensions Weight

Estimated

Moisture

Content

Relative

Humidity

Heat

Release

Rate

Test Duration

Test 9 Cribl Fir .6x.6x.6 m

(2x2x2 ft)

48.1 kg

(1061b)

13% 63% 0.41 MW 275 s

Test 10

Crib 2

Fir

.6x.6x.6 m

(2x2x2 ft)

50.8 kg

(112 1b) 13% 63% 0.64

MW 615s

Cribs

.6x.6x.6 m

(2x2x2 ft)

51.2 kg

(113 1b)

Table 76. Response times of photoelectric smoke detectors during wood crib fires conducted in 1

m high facility.

detector did not activate

- no detector installed

n/a no average

3.0 m 6.1m 8.5 m 9.1m 10.7 m 11.6 ra (38 ft)

13.7 m i

(45 ft)

I-/UCitllUIl (10 ft) (20 ft) (28 ft) (30 ft) (35 ft)

Test 9 - 0.6 m X 0.6 m X 0.6 m wood crib

|l North 67 s 58 s - - - -

East 42 s

- -

South 59 - - s -

West 46 s - -

Average 52 s 58 n/a n/a n/a n/a n/a

Test 1 - 0.6 X 0.6 m X 1 .2 m wood crib

1 North 76 s 80s 89 s - - - -

East 59 s 88 s

- 121 s - 138 s 126 s

South 60s 72 s 113s - 118s - -

West 38 s 72 s - 100 s

- 134 s 159 s

Average 58 s 78 s 101s 111 s 118s 136 s 143 s
308 Appendix

Table 77. Projected beam detector response times for wood crib fires (tests 9 and 10)

conducted in 1 5 m high facility

Location

Below

Ceiling

Sensor Number

, Ki-"- : ... B2««;,; .B3<^':,.,..:. :,B4<*L:: W^ ;: B^^"' : B7fr>

...P***^:.:.: B9f^>

Test 9 - 0.6 m X 0.6 m X 06. m wood crib

03 m :.:.::::::lii:.:::;:.:s .:...ll::l::....:::: mMM,, :;::::.:.:.;::;:::: _._:.:;..,.-.,.,.,,; -.v.- —... .^ ^ ;::..... ".:::.:;;: :: -viii

1.8m - - - - - - 330 s 313s 305 s

2.7 m K- * •*• 33T s : 46 $7;; 305 s'

. , - " 11

Test 1 - 0.6 m X 0.6 m X 1.2 m wood crib

0.3 m 205 s 67 s 100$ - : .'-' - - -

1.8 m - - - - - - 568 s 563 s 2.7 m -

.......:,v..v.:...v,,.xg ^-?-^:m mm'sm'mwm- - - -

detector did not activate

- no detector installed

(a) alarm sensitivity setting, 30%; alarm window, 30 s (b) alarm sensitivity setting, 20%; alarm window, 5 s (c) alarm sensitivity setting, 50%; alarm window, 30 s (d) alarm sensitivity setting, 50%; alarm window, 10 s (e) alarm sensitivity setting, 50%); alarm window, 5 s

Table 78. UV/IR optical flame detector response times for wood crib test fires conducted in 1 5 m

high facility

Test 9: 0.6 m x 6.6 m x 0.6 m wood crib

Location (m)

9.7 OVHD 12.2 15.215.2 Off Axis

18.3 21.3 24.4 27.4 30.5 48.8

Response

Time (s) 0.3 35.9 71.7 36.0 81.3 93.2 113.9 121.7 180.3

Test!.0: 0.6 m X 0.6 m X 1.2 m wood crib

Location (m)

9.7

OVHD

15.2 Off Axis

18.3 21.3 24.4 27.4 30.5 36.6 42.7 48.8

Response

Time (s) 528.1 102.7 387.5 392.6 441.3 445.7 552.0 584.8

detector did not activate
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Analysis of tests 9 and 10 show a distinct pattern. Two of the three detectors at the lowest elevation (i.e., 2.7 m below the ceiling) did not activate because the smoke layer did not descend to that level. The

center detector responded quickly because its beam was aimed directly through the plume. Had this detector been located elsewhere it probably would not have responded. The detectors at the middle

elevation (i.e., 1 .8 m below the ceiling) either did not respond or took longer than 560 s to respond. The

sensitivity setting of the detectors at this level was set at 50 %. A 50 % decrease in signal strength was

too high for the beam detectors to generate an alarm. The response times for the detectors located at the

highest elevation (i.e., 0.3 m below the ceiling) were consistent between test 9 and test 10. It is important to note that the draft curtains were removed prior to conducting the wood crib tests. Had the

draft curtains been in place, there is a high probability that the projected beam detector response would

have been significantly different.

Response ofCombination UV/IR Optical Flame Detectors

The installation parameters for the UV/IR detectors are described in section 3. The location of the

UV/IR detectors is shown in Figure 145. For both wood crib tests the controllers for the UV/IR detectors

had the following settings: 0.25 s gate length, 4 counts per gate and 4 consecutive gates. There were nine

UV/IR detectors mounted on the floor, approximately 2.0 m high. Eight of these detectors were

positioned to provide a direct line of sight to the fire and one detector was positioned off axis at a 45 ° angle to the fire. In addition there was one detector installed directly over the crib, attached to the

bottom of the truss, 9.7 m above the floor. The UV/IR detector response times for tests 9 and 10 are shown in Table 78. In all of the jet fuel experiments, the manufacturer also furnished the predicted

response on unitized UV/IR detectors; however, this was not done for the wood crib experiments.

Figure 146 shows the comparison of response times versus detector locations in test 9. The response

times ranged from 0.3 seconds at the overhead detector to 180 seconds at the detector located 30.5 m

from the fire. The detector 48.8 m from the fire did not activate. There was a noticeable difference

between the two detectors 15.2 m from the fire (i.e., the off axis detector and a detector looking directly

at the source). The detector that was positioned off axis from the source responded in half the time as the

detector that was looking directly at the source.

In test 10, the response times were very different from test 9. The off axis detector (i.e., 15.2 m from the

source) responded in 103 s, while the other detectors responded between 387 s and 585 s. Visual

observations showed (Figure 147) that in test 10, the flames were primarily confined to the interior of

the crib for the first 6 min of the test. During this time the flame detectors were being blocked by the

smoke and could not pick up the deep seated fire within the crib, even though there was significant

flaming combustion. These detectors did not respond until the flames grew to a height above the wood

crib which than became visible to the detectors.

Response ofAutomatic Sprinklers

The automatic sprinkler installafion parameters and mounting locations are discussed in section 3. No

sprinklers activated in either test 9 or 10. The maximum temperature recorded at the ceiling directly

above the plume centerline were 53 °C (127.4 °F) in test 9 and 52 °C (125.6 °F) in test 10. The lowest

temperature sprinklers installed were rated at 79 °C (175 °F).
312 Appendix

Maximum Ceiling Temperature and Temperature Rise Above Ambient

There were 64 thermocouples installed in the test area as described in section 3. For tests 9 and 10, the

maximum ceiling temperatures were 53 °C (127.4 °F) and 52 °C (125.6 °F) respectively. In addition the

temperature rise above ambient was 24 °C (43.2 °F) for test 9 and 23 °C (41.4 °F) for test 10. It is important to note that the maximum ceiling temperature and temperature rise above ambient were

obtained from the thermocouples mounted at the ceiling, directly over the fire plume.
Appendix 313

Overhead - 9.7 m

O 36.6

O 42.7 m

48.8 m

n Test #9 Only

O Test #10 Only

Both Test #9 and #10

Figure 145. UV/IR optical flame detector layout for wood crib fire tests (tests 9 and 10) conducted in 15 m high facility.
314 Appendix a ^

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Federal Information Processing Standards Publications (FIPS PUB)—Publications in this series

collectively constitute the Federal Information Processing Standards Register. The Register serves as the

official source of information in the Federal Government regarding standards issued by NIST pursuant t^ the Federal Property and Administrative Services Act of 1949 as amended, Public Law 89-306 (79 St 1127), and as implemented by Executive Order 11717 (38 FR 12315, dated May 11, 1973) and Par'

Title 15 CFR (Code of Federal Regulations).

NIST Interagency Reports (NISTIR)—A special series of interim or final reports on work pe- --y NIST for outside sponsors (both government and nongovernment). In general, initial distributir .ed by the sponsor; public distribution is by the National Technical Information Service, Springf' .2161,

in pap)er copy or microfiche form.