1983 CENTER FOR FIRE RESEARCH ANNUAL CONFERENCE ON FIRE RESEARCH

(Summaries of Research Grants and CFR

In-House Programs)

August 23-25, 1983

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Washington, D.C. 20234

July 1983

QC

100

.U56

#82-2612-

Preprint of the 1983 Center for Fire Research

Annual Conference on Fire Research to be Held

August 23-25, 1983

1983 CENTER FOR FIRE RESEARCH ANNUAL CONFERENCE ON FIRE RESEARCH

(Summaries of Research Grants and CFR

In-House Programs)

August 23-25, 1983

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Washington, D.C. 20234

July 1983

Malcolm Baldrige, Secretary of Commerce

Ernest Ambler, Director, National Bureau of Standards

Preprint of the 1983 Center for Fire Research

Annual Conference on Fire Research to be Held

August 23-25, 1983

FOREWORD

The Seventh Annual Conference on Fire Research honors Professor

Howard Emmons who retires from Harvard University this year. Professor

Emmons has provided leadership and inspiration to many in this field as attested by the breadth and depth of the topics in the conference

modeling of fire growth, flame phenomena and spread, diffusion flames

and radiation, fire plumes , extinction and suppression—and the contributions

of those he has taught. Howard Emmons has demonstrated the viability of

scientifically based fire protection engineering practice.

Of course, much remains to be done. The conference program and papers

(to be published separately) provide a good indication of where we are in

a numoer or crt-txcal areas of tare science. Thas document contaans summaraes

of Center for Fire Research in-house and grants work. This ongoing work i£

intended to sustain the momentum in fire science research that has built up over the last decade and to continue the development of rigorous fire

protection engineering practices.

This year has been an important one of testing for the Center for

Fire Research in the budget process. The results have been most gratifying,

and that challenge appears to be behind us. We hope now to focus fully on

the technical issues before us and welcome the opportunity to work with

all of you on addressing them.

Jack E. Snell, Director

Center for Fire Research
'
TABLE OF CONTENTS

Page

FOREWORD iii

ABSTRACT 1

CENTER FOR FIRE RESEARCH PROGRAMS

Ad Hoc Working Group of Mathematical Fire Modeling 2

Exploratory Fire Research 3

Facility Fire Safety Performance 8

Fire Growth Processes 15

Fire Performance and Validation 21

Fire Research Information Services 26

Fire Risk Analysis 27

Fire Suppression and Extinguishment 30

Fire Toxicology 33

Materials Fire Properties 36

Smoke and Toxic Gases 39

GRANTS AND CONTRACTS

American Institute of Architects Foundation

Fire Safety Evaluation System for Board and

Care Homes 42

Brown University

Effects of Material Properties on Burning and

Extinction-Fires on Vertical Fuel Surfaces 44

California Institute of Technology

Experimental Study of Environment and Heat

Transfer in a Room Fire 48

Case Western Reserve University

Experimental and Analytical Study of Fire

Sprinkler Scaling Laws 52

v
Page

Case Western Reserve University

Flame Spread and Spread Limits 54

Clemson University

Ternary Reactions Among Polymer SubstrateOrganohalogen-Antimony Oxides in the Condensed

Phase Under Pyrolytic, Oxidative and Flaming

Conditions 57

Colorado School of Mines

Characterization of Aerosols from Fires 60

Factory Mutual Research Corporation

Computer Modeling of Aircraft Cabin Fire

Phenomena 64

Factory Mutual Research Corporation

Determination of Fuel Parameters for

Fire Modeling 66

Factory Mutual Research Corporation (Joint

Program with Harvard University)

Prediction of Fire Dynamics 69

Harvard University

The Prediction of Fire Dynamics • 75

National Fire Protection Association

Investigation and Analysis of Major Fires 78

Pennsylvania State University

An Investigation of Turbulent Fires on Vertical and Inclined Walls 87

Princeton University

Flow Field Effects on the Sooting Structure

of Diffusion Flames 91

SRI International

Continued Development of Residential Fire

Decision Analysis Model 94

SRI International

Polymer Degradation During Combustion 96

TRW

Modeling of Wind-Aided Flame Spread 98

vi
Page

University of California, Berkeley

Dynamics of Smoke and Inert Tracers Produced

in Porous Fuels 102

University of California, Berkeley

Fire Propagation in Concurrent Flows 106

University of California, Berkeley

Intralaboratory Evaluation of a Standard

Room Fire Test 110

University of California, Lawrence Berkeley

Laboratory

Fire Modeling 114

University of California, Lawrence Berkeley

Laboratory

Flame Radiation 118

University of Florida

Network Models of Building Evacuation:

Development of Software System - Year Two 121

University of Maryland

The Determination of Behavior Response

Patterns in Fire Situations, Project

People II 125

University of Michigan

Degradation of Mechanical Properties of

Wood During Fire 128

University of Montana

Chemistry of Smoldering Combustion and

Its Control 132

University of Notre Dame

Computer Modeling of Aircraft Cabin Fire

Phenomena 136

University of Notre Dame

Scaling Correlations of Flashover Experiments 140

University of Pittsburgh

Toxicity of Plastic Combustion Products 143

vii

1983 CENTER FOR FIRE RESEARCH ANNUAL CONFERENCE ON FIRE RESEARCH

August 23-25. 1983

Abstract

This report contains extended abstracts of grants

and contracts for fire research sponsored by the Center

for Fire Research, National Bureau of Standards, as well

as descriptions of the internal programs of the Center

for Fire Research.

Key words: Combustion; decision analysis; fire models;

flame spread; human behavior; ignition; polymers; smoke;

soot; toxicity: wood.

1
AD HOC WORKING GROUP OF MATHEMATICAL FIRE MODELING

CENTER FOR FIRE RESEARCH

FY 83

Professional Personnel

Robert S. Levine, Chairman of Steering Committee

John A. Rockett, Chairman of Computer Committee

James G. Quintiere, Chairman of Models Subcommittee

Note: The Modeling Committee is chaired by Professor Howard Emmons of

Harvard University, the Subprogram Committee by John de Ris of

Factory Mutual, and the User's Needs Committee by Irwin Benjamin

of Benjamin-Clarke.

A number of CFR personnel are members of the technical committees.

Program Objectives

The objectives of this committee are to facilitate the development and use of mathematical models of fire and to coordinate and facilitate

research needed to improve the models. The steering committee includes

members from other government agencies who have influence on their

agencies' research and development in this field. The coordination, of

course, is voluntary.

Project Areas

Each applicable area is included in another program abstract. The major

portion of the CFR effort is in the Fire Modeling Program.

Associated Grants

Several grants as listed elsewhere.

2
EXPLORATORY FIRE RESEARCH

FIRE MEASUREMENT AND RESEARCH DIVISION

CENTER FOR FIRE RESEARCH

FY 83

Professional Personnel

Kermit C. Smyth, Research Chemist and Head

James E. Brown, Research Chemist

Toshimi Hirata, Guest Worker

Takashi Kashiwagi, Materials Research Engineer

W. Gary Mallard, Research Chemist

J. Houston Miller, Faculty Research Associate

Thomas J. Ohlemiller, General Engineer

William M. Pitts, Research Chemist

Kathleen E. Werner, Chemist

Program Objectives

(1) Improve the understanding of the chemical and physical processes

which underlie macroscopic fire phenomena. The research embraces

broad areas covering both solid and gas phase processes, with

particular attention to polymer degradation, the effects of

radiation, and the hot gas chemistry and physics leading to

incomplete combustion.

(2) Devise new techniques and methods for studying these phenomena.

(3) Furnish fundamental scientific information to support the other

activities within the Center for Fire Research.

Scope

This work is scientific not empirical. It embraces broad areas underpinning CFR programs with focussed study in the areas of materials

degradation, hot gas physics and chemistry, and radiation. Efforts are

directed towards improved understanding of the chemical and physical

processes which underlie macroscopic fire phenomena and include

development of new techniques and methods for studying these processes.

Proj ects

1. Polymer Gasification and Ignition

Transient gasification characteristics of polymeric materials under

nonflaming conditions are being investigated at fire level radiant heat

fluxes. Results show that the gas phase oxygen level has a marked

effect on the rate of gasification and also decreases the averaged

molecular weights and affects their distribution in the polymer

undergoing depolymerization. Molecular weight distributions of PMMA

3
residues have been measured by gel permeation chromatography. Two types

of residues were studied; one from a thermally thick sample irradiated

under non-flaming conditions with thermal radiation from an electrically

heated graphite plate. The other was a small, thermally thin sample

('v- 10 mg) heated iso thermally . The former samples were exposed to

different radiant fluxes, to different atmospheres containing various

concentrations of oxgyen, and for different exposure times. Eight to

ten thin layers (

'v 125 pm thick) were sliced from the surface, and

their molecular weight distributions were measured. Results indicate

that the effects of gas phase oxygen on the molecular weight distribution appear as deep as 0.6 mm. The broad molecular weight distribution

(large polydispersivity of 5-10) indicates that a mixture of oxidized

and non-oxidized PMMA exists in the molten layer near the surface.

The objective of the isothermal experiment with small PMMA samples is

to obtain values of degradation kinetic constants and to understand the

degradation mechanisms. The observed molecular weight distributions

indicate that the values of the polydispersivity are close to 2 in both

nitrogen and air. This means that the molecular weight distribution of

degradating PMMA follows the most probable distribution. In air the

number averaged molecular weight of PMMA decreased sharply, falling

below 10% of the original averaged molecular weight values at about 10%

weight loss. Thus, the effect of gas phase oxygen on the reduction of

the molecular weight is significant even at small weight loss. These

preliminary data indicate that the initiation mechanism of thermal

oxidation of PMMA appears to be random scission.

Kashiwagi, T., "Effects of Sample Orientation on Radiative Ignition",

Combustion and Flame 44, 223 (1982).

Kashiwagi, T. and Kashiwagi, T. , "A Study of the Radiative Ignition

Mechanism of a Solid Fuel Using Holographic Interferometry", presented

at the AIAA 20th Aerospace Sciences Meeting, Jan., 1982.

Kashiwagi, T. and Ohlemiller, T.J., "A Study of Oxygen Effects on Nonflaming Transient Gasification of PMMA and PE During Thermal

Irradiation", 19th International Symposium on Combustion (to be

published)

.

2. Smoldering Combustion of Cellulosics

The propensity for smoldering exhibited by cellulosic materials

continues to be a subject of major concern. The smolder characteristics of cellulosic insulation (made from wood pulp) represent the

present focus for this work. Smolder propagation through a thick

horizontal layer of such insulation has been investigated. Temperature, oxygen, and remaining solid fuel distributions have been

measured as a means of determining the factors controlling propagation. The overall structure appears to be determined by the diffusion

of oxygen. Boric acid slows the propagation and alters the smolder

wave structure, but does not cause extinction in these thick layers.

4
There are two overall stages of oxidation (oxidative pyrolysis and char

oxidation) that couple together to support smolder propagation in a thick layer.

The smolder initiation process, however, depends solely on the oxidative

pyrolysis. The qualitative impact of additives on this reaction stage

can be measured by means of differential scanning calorimetry, and the

results can be used to make predictions about how the additives will

affect the smolder ignition temperature. The oxidation behavior of the

wood fibers and their components (cellulose, lignin, etc.) is being

compared to see which of these contributes the most to the low

temperature exothermicity responsible for smolder initiation.

The transition from smoldering to flaming combustion as a result of

increased air flow is being investigated experimentally. The configuration of most practical interest is a horizontal layer of fuel over

which a varying air flow passes. The critical air flow for transition

is being investigated parametrically. Future plans include mechanistic

studies of the transition process.

Mulholland, G. and Ohlemiller, T.J., "Aerosol Characterization of a Smoldering Source", Aerosol Science and Technology 1_, 59 (1982).

Ohlemiller, T.J. and Lucca, D.A. , "An Experimental Comparison of Foward

and Reverse Smolder Propagation in Permeable Fuel Beds", Combustion and

Flame (to be published)

Ohlemiller, T.J., "Modelling of Smoldering Combustion Propagation",

Progress in Energy and Combustion Science (to be submitted)

3. Products of Wood Combustion

The objective of this research is to understand the degradation processes of wood under fire conditions and the formation and evolution of the

combustion products. Major support for this work comes from the

Department of Energy under its residential alternate fuels program.

Our prior studies began to elucidate the chemical processes occurring

in the fuel itself under controlled pyrolysis. High resolution nuclear

magnetic resonance spectra clearly show the evolution from a cellulo sic /lignin structure to a highly aromatic structure. Gaseous

samples from various locations in the stack of a wood stove show no chemical change once they leave the firebox. Current work is focused

on the conversion of wood to fuel gases at various heat fluxes and with

varying ambient oxygen levels. The products from transiently gasifying,

thermally thick samples of wood and wood components are captured and

analyzed. The global pyrolytic degradation and oxidation kinetics of

representative gasification products will be examined.

4. Soot Formation Chemistry and Physics

Flame radiation from incandescent soot dominates flame spread and heat

transfer in large fires. Escaping particulates hinder vision and impair

5
breathing, as well as being a sensitive signature for fire detection.

Despite this importance, there is little understanding at the molecular

level of the soot formation process; i.e., how small molecules grow

rapidly to become soot particles. We are now in the fourth year of a long-term study of the fundamental chemistry and physics of soot formation, carried out jointly with the NBS Thermal Processes Division in the

Center for Chemical Engineering.

Our studies have included a wide range of optical and mass spectronetric

experimental work, as well as theoretical models of the condensation of

large molecules. On the experimental side, new data for proposed models

of soot formation have been obtained by investigations of ( 1 ) the

ion-molecule chemistry of 0333"*’, thought to be a key precursor and ( 2 ) fluorescence from polycyclic aromatic molecules, which are likely to be

important building blocks in soot formation. In addition, by using the

optogalvanic effect in flames the laser- induced ionization of very small

scot particles has been observed . Mere recently, multiphoton ionization

experiments on several hydrocarbons have established this technique as extremely sensitive for flame diagnostics. Multiphoton ionization may

prove to be very useful in detecting the formation and decay of specific

intermediate size organic molecules in a non- intrusive manner. We will

also be characterizing the radical pool in various flames to determine

the relevance of premixed flame data to diffusion flames. On the

theoretical side, our work on condensation processes seeks to establish

the molecular size below which chemical reaction kinetics dominate and

above which the physical condensation process is controlling. Methods

of calculating the dispersive and overlap parts of the intermolecular

potential for polycyclic aromatic hydrocarbons of D^ symmetry have

been developed. The resulting total potentials are used to predict

stable dimer configurations and the corresponding binding energies.

Smyth, K.C., Lias, S.G, and Ausloos, P., "The Ion-Molecule Chemistry of

C 3 H 3

'

1' and the Implications for Soot Formation", Combustion Science and

Technology 28, 147 (1982).

Miller, J.H., Mallard, W.G., and Smyth, K.C., "The Observation of LaserInduced Visible Fluorescence in Sooting Diffusion Flames", Combustion

and Flame 44 , 61 (1982)

.

Mallard, W.G., Miller, J.H. , and Smyth, X.C., "Resonantly Enhanced TwoPhoton Photoionization of NO in an Atmospheric Flame", Journal of

Chemical Physics 75 , 3483 (1982).

Smyth, K.C. and Mallard, W.G., "Two-Photon Ionization Processes of ?0 in

a C 2 H£/Air Flame", Journal of Chemical Physics 1779 (1982).

Miller, J.H., Mallard, W.G., and Smyth, K.C., "Intermolecular Potential

Calculations for Polycyclic Aromatic Hydrocarbons”, Journal of Chemical

Physics (submitted).

6
5. Turbulent Chemically-Reacting Flow

In a large fire plume, the combustion region is turbulent and is

characterized by highly variable (both spatial and temporal) distributions of temperature and species concentration. In such cases the

flame properties are dominated by the substantial temperature and

species concentration fluctuations. Due to the scarcity of measurements on such systems and the complexity of the phenomena, the

understanding of turbulent fire plumes is poor. We have initiated

an investigation of turbulent chemically-reacting flow for the

purpose of enchancing the understanding of the nonlinear coupling

which occurs between chemical reaction and turbulent flow mixing.

Currently, as a first step in a planned series of experiments, the

effect of density differences on the mixing behavior of a turbulent

jet with its surroundings is being investigated. A novel technique

using combined Rayleigh light scattering and hot-wire anemometry has

been developed for performing simultaneous time-resolved concentration

and velocity measurements in the flow field. Detailed measurements

are being made for axisymmetric turbulent jets of C 3 Hg, CH4 , CO 2 , and He mixing with coflows of air or CO 2 . Furture work will

incorporate chemical reaction into the experimental system. The

experimental work is to be coupled with a theoretical modeling effort.

Pitts, W.M. and Kashiwagi, T. , "The Application of Laser-Induced

Rayleigh Light Scattering to the Study of Turbulent Mixing", NBS-IR 33-

2641 and Journal of Fluid Mehcanics (submitted)

.

Pitts, W.M., McCaffrey, B.J., and Kashiwagi, T., "A New Diagnostic

Technique for Simultaneous, Time-Resolved Measurements of Concentration

and Velocity in Simple Turbulent Flow Systems", Fourth Symposium on Turbulent Shear Flows, Karisruhe, Germany, Sept. 1983.

Associated Grants and Contracts

1. Sharon K. Brauman - SRI International, "Polymer Degradation During

Combustion."

2. Michael J. Drews and Christine W. Jarvis - Clemson University,

"Ternary Reactions Among Polymer Substrate-Organohalogen-Antimony

Oxides in the Condensed Phase Under Pyrolytic, Oxidative and Flamin

Conditions ."

3. Irvin Glassman, Ian M. Kennedy, and Frederick L. Dryer, Princeton

Univeristy - "Flow Field Effects on the Sooting Structure of

Diffusion Flames."

4. Patrick Pagni - Lawrence Berkeley Laboratory, "Fire Modeling."

5. Fred Shafizadeh - University of Montana, "Chemistry of Smoldering

Combustion and Its Control."

6 . Chang-Lin Tien - Lawrence Berkeley Laboratory, "Flame Radiation."

7
Facility Fire Safety Performance

Center for Fire Research

FY 83

Professional Personnel

Harold E. Nelson, Head

Bernard M. Levin, Research Psychologist

Leonard Y. Cooper, Research Fire Protection Engineer

A. Jeffrey Snibe, Research Fire Protection Engineer

W. Douglas Walton, Research Fire Protection Engineer

David Stroup, Fire Protection Engineer

Philip Chen, Research Engineer

Eric Rosenbaum, Coop Student-Fire Protection Engineer

Steven Thome, Coop Student-Fire Protection Engineer

Program Ob j ectives

The objectives of the Facility Fire Safety thrust encompass the development

of a system of relevant engineering methods for use in predicting the

performance of facilities and people in response to the potential fire

threats

.

This thrust focuses on development of a wide range of fire protection

systems, models, and other tools targeted for the practicing fire

protection engineering, design, or regulatory professional. It utilizes

the state of the art in scientific knowledge, physical property data,

empirical results from tests, fire experience, and sound engineering

practice judgment. It involves development of a framework of macro models

and other systems for setting performance requirements and/or evaluating

active and passive systems for facility fire protection and use. It

draws heavily on closely related activities in the area of fire growth

processes, suppression and extinguishment, smoke and toxic gases, building

response, and human response.

Proj ect Areas

1 . Engineering Methodologies for Predicting Facility Fire Safety

Performance

The purpose of this project area is the development of a consistant

system of scientifically based engineering methods for predicting

the performance of facilities and people in response to a potential fire.

8
Significant progress items include:

a. The development and initial exercise of a total deterministic system

linking engineering models and calculations into a facility performance

system. (See attached figure)

b. The completion and publication of a user friendly computer program

for calculating available safe egress time. The current program handles

fire growth in a single space and sets a model approach for handling

multi-space problems. The processes is on-line and has demonstrated

transferability between computers and useability by practicing engineers.

c. The development and completion of initial report of an escape and rescue model having capabilities of appraising the time involved in

undertaking emergency actions for evacuation, rescue, or other purposes.

(This work has been undertaken jointly by the American Institute of

Architect Research Corporation and the CFR staff)

d. The publication of the first laboratory acquired data on the time

increments involved in important acts necessary for successful evacuation.

e. Improved concepts for use in the available egTess time modeling on

the convected heat transfer to ceilings above enclosure fires and the

significance of wall effects during growth stages of enclosure fires.

f. Development of an optimization mode to the escape and rescue model.

g. Improvement of the subsystems within the engineering models with

emphasis on the response of fire protection devices and involvement of

combustible ceilings or other linings.

h. Increased activity in transferring of engineering methodology to the

applied fire protection engineering field.

With the help of important financial assistance from the Dept, of Health

and Human Services, (HHS) , an enhancement of this project has been

initiated. The concepts of the engineering methodologies are being used

to address a series of "Life Safety Code” types of problems of concern

to HHS. Work will involve the definition and solution of the code

problems in engineering terms, the execution of large scale tests to

validate the solutions, and derivation of validated or otherwise

accredited field applicable engineering solutions to the basic problems.

The problem areas concern fire development and transport of hazardous

conditions throughout a smoke zone of origin, the impact of such on the

surrounding barriers (smoke doors, dampers, etc.) of the smoke zone, and

the response of heat and smoke detectors and automatic sprinklers

within the space.

The directions in engineering methodology project include:

9
(a) Completion of a first facility fire safety performance model

using the HHS sponsored data as a base and presenting the best

transferable current state of the art.

Cb) The development and proofing of multi-room methods of analyses

of hazard in building spaces.

(c) Development of essential human factors subsystems for the

engineering methods approach.

2. Rational Fire for the National Park Service

Emphasis on this past year has been on the completion of a fire safety

evaluation system covering overnight accommodations in the national park

system. The Park Service now has the evaluation system and is in the

process of applying it in the field. In the process, extensive training

of park service personnel and the development of a guidance manual, for

use by architects and maintenence personnel not intimately familiar with

fire protection terminology, has been developed. Advances have also been

made on the development of a priority calculation method to assist the

National Park Service in gaining the greatest return for expenditures in

my safety improvements.

More recently the Park Service has requested extension of the project to

address problems in museums, historical buildings, and similar types of

public facilities that are not involved in overnight accommodations. An

effort is now underway to develop an evaluation system that- will be based

on engineering methodologies rather than a professional judgment. This

phase of the project is just underway and examination of typical buildings

is being made.

3. Coal Mine Fire Safety Evaluation

This project is concentrating on the development of an alternative means

for evaluating fire safety in coal mines. The project is in its second

phase involving the development of a suitable fire safety evaluation

concept that can be reviewed and tested through establish consensus

methods. It was intended to be beyond phase 2 and into the proofing

phase by this date. The problem has, however, been more difficult than

anticipated and additional means of seeking concensus among the advisory

group and bringing the critical question into appropriate focus for such

appraisal are being pursued at this time. The field test and consensus proofing phases cannot be started until the initial consensus has been

achi eved.

4 . Rational System for Health Care Facilities

A significant portion of the current activities in this area relative to

"Life Safety Code" questions is covered under the first project of this

report on engineering methodologies. This subject covers the work that

10
has been underway over the last several years on the development o~ evaluation systems for board and care facilities.

Board and Care Homes house persons or groups that have less capability

of avoiding fire threat than the general population but are not in need

of the level of care provided by institutional occupancies such as hospitals and nursing homes. While these homes have many names such as group

homes for the developmentally disabled, residential care facilities, and

community residential facilities, they all are designed to provide needed

assistance in a less restrictive, more stimulating, more pleasant and,

hopefully, less expensive environment than that which would be provided

by an institution. The Homes provide a sheltered residence for people

with a wide range of disabilities ranging from mental retardation, or physical injuries to frailty due to age. The services provided include

lodging, food, and the social support of group or family style living.

Additional services sometimes include rehabilitative training, assistance

in handling personal finances, purchasing of clothing, transportation to

medical services, etc. The residential structure includes buildings

typical of single family residences, large and small hotels, and apartment buildings.

This project has been progressively underway for several years and is

nearing completion. The major task of the project has been the development of a Fire Safety Evaluation System for Board and Care Homes (FSES/

B$C) . The FSES/B8C provides a flexible instrument of for evaluating

the fire safety of the homes . It is based on a proposed new Chapter of

Life Safety Code covering thi occupancy as a new class of occupancy.

Both the proposed chapter and FSES/B8C are under active review and

consideration by the National Fire Protection Association for inclusion

in the next edition of the Life Safety Code.

The evaluation system provides a grading system to determine the emergency

evacuation difficulty potential in groups of persons that include residents

with varying degrees of difficulty supported by staff that can do some degree compensate for those shortcomings during an emergency. The proposed

chapter to the Life Safety Code and accompancying evaluation system also

includes fire safety evaluation systems for determining the level of

facility safeguards provided in small residential type structures, larger

hotel type structures, and apartment buildings used to house one or more

board and care facilities. The level of facility safeguard is coordinated

with the degree of evacuation difficulty involved.

The FSES/B&C was published with a description of its development and

testing in NBSIR 83-2659 "A Fire Safety Evaluation System for Board and

Care Homes." Current effort involves working with the appropriate

committees of NFPA in their review and potential modification of the

FSES/B5C, and working with various Federal and state agencies in their

review of the System for potential adoption.

11
A second important task has been the development of a manual to assist

the owners and operator s of Board and Care Homes to upgrade the fire

safety of their homes through better planning and improved training

of the residents.

The manual prepared at the University of Maryland has been published as NBS-GCR-82-408 , "A Matter of Time--A Comprehensive Guide to Fire Emergency Planning for Board and Care Homes” by N.E. Groner.

Associated Grants

1. University of Maryland, John Bryan, The Determination of Behavior

Response Patterns in Fire Situations - Project People II. (Completed

1983)

2. North Carolina State Universtiy, Richard Pearson, Occupant Egress

from Simulated Fires. (Completed 1983)

3. University of Maryland, Norman Groner, The Development and Field

Testing of a Fire Safety Manual for Board and Care Homes Operators.

(Completed 1982)

4. University of Washington, John Keating and Elizabeth Loftus, Post

Fire Interviews: Development and Field Validation.

5. AIA Research Corporation, Earle Kennett, Fire Safety Evaluation

System for Board and Care Homes (Escape and Rescue Model).,

6. University of Washington, Norman Groner and John Keating, A Fire

Emergency Planning and Training Manual for National Park Residential

Buildings

.

7. University of Florida, R.L. Francis and T.M. Kisco, Network Models

of Building Evacuation: Development of Software System.

Publications (and other products)

1. Calculating Available Safe Egress Time (ASET) - A Computer Program

and User's Guide, Cooper, L.Y. and Stroup, D.W., presented at the 1982

CFR Annual Research Conference; NBSIR 82-2578.

2. A Concept for Estimating Available Safe Egress Time in Fires, Cooper,

L.Y., Fire Safety Journal, 5(2), pp. 135-144, 1983.

3. A Mathematical Model for Estimating Available Safe Egress Time in

Fires, Cooper, L.Y., Fire Materials, 6, (3/4), p. 135-144, 1982.

4. The Development of Hazardous Conditions in Enclosures with Growing

Fires, Fires, Cooper, L.Y., presented at 1982 Fall Meeting of the Eastern

Sect, of Combustion Institute with abbreviated version of paper appearing

in Proceedings of the Meeting; NBSIR 82-2622; to appear in Combustion

12
Science and Technology.

5. Convective Heat Transfer to Ceilings Above Enclosure Fires, Cooper,

L.Y., presented at the 19th International Symposium on Combustion, August,

1982; and appears in Proceedings of the Symposium.

6. On the Significance of A Wall Effect in Enclosures with Growing Fires,

Cooper, L.Y., presented at 12/18/82 Ad Hoc Math Modeling Committee Meeting,

and at 1982 Fall Conference of the Eastern Section of the Combustion Inst.,

to be presented at 1983 ASME/AICHE National Heat Transfer Conference and

at 1983 .Annual CFR Research Conference; to appear as NBSIR; to be submitted for publication.

7. Life Safety Through Designed Safe EgTess - A Framework for Research,

Development and Implementation, Cooper, L.Y., and Nelson, H.E., CFR

Memorandum for File, Jan. , 1982; presented at the UJNR Fire Research Panel

Meeting, May, 1982; and appearing in Proceedings of the Meeting.

8. Heat Transfer From a 3uoyant Plume to an Unconfined Ceiling, Cooper,

L.Y., Journal of Heat Transfer, Vol. 104, No. 3, 1982.

9. An Experimental Study of Upper Hot Layer Stratification in Full-Scale,

Multiroom, Fire Scenarios, Cooper, L.Y. Harkelroad, M. , Quintiere, J.

Rinkinen, W. , Journal of Heat Transfer, Vol, 104, No. 4, 1982.

10. A Mathematical Simulation of Enclosure Fire Phenomena and Its Application to Life Safety, Cooper, L.Y., presented at a Rutger's University

Mechanical and Aerospace Engineering Colloquium, May, 1982.'

11. The Concept of Life Safety Through Designed Safe Egress, Cooper,

L.Y., presented at the 1982 NFPA Conference (Architects, Engineers and

Building Code Official Section)

12. A Buoyant Source in the Lower of Two Homogeneous, Stably Stratified

Layers - A Problem of Fire in an Enclosure, Cooper, L.Y., to be presented

at the Symp. of Modeling of Enclosure Flow Systems during 1983 Annual

ASME Conference and to appear in Symp. Proceedings, to appear as N3SIR.

13. The Need and Availability of Test Methods for Measuring the Smoke

Leakage Characteristics of Door Assemblies, Cooper, L.Y., presented as a report on 12/6/82 ASTM E5 . 12 Committee on Protection of Openings; to

appear as NBSIR; (abstract) subcommittee for presentation of 1984 ASTM

Symp. on Application of Fire Science to Fire Engineering; manuscript

under NBS review.

14. Smoke Movement in Rooms of Fire Origin and Adjacent Spaces, Cooper,

L.Y., to be presented at 1983 SFPE Symp. on Smoke - Its Chemistry,

Physics and Control Through Engineering; manuscript under NBS review,

to be submitted for publication.

13
15. Occupancy Types-- Relative Hazards, Cooper, L.Y., to be presented

at the Manhatten College Fire Engineering Institute's 1983 (First) .Annual

Fire Engineering Conference.

16. A Fire Safety Evaluation System for Board and Care Homes, Nelson,

H.E.; Levin, B.M.; Shibe, A.J.; Groner, N.E.; Paulsen, R.L.; Alvord,D.M.;

and Thome, S.D.; NBSIR 83-2659.

17. A Matter of Time--A Comprehensive Guide to Fire Emergency Planning

for Board and Care Homes, Groner, N.E.; NBS-GCR-82-408

.

18. Egress Behavior Response Time of Handicapped and Elderly Subjects

to Simulate Residential Fires Situations, Pearson and Joost, North

Carolina State University, NBS-GCR-83-429

.

19. Implication for Codes and Behavior Models from the .Analysis of

Behavior Response Patterns in Fire Situations as Selected from the

Project People and Project People's Study to Programs, Bryan, John;

University of Maryland, NBS-GCR-83-425

.

20. A System for Fire Safety Evaluation for Multifamily Housing,

Nelson, H.E. and Shibe, A.J.; NBSIR 82-2562.

21. User Guide for the Application of Table 1-Safety Parameter Values

for the Fire Safety Evaluation System for National Park Service

Facilities, Bush, K.; Bradley, H. ; Hicks, H., NBS-GCR-83-427

.

14
FIRE GROWTH PROCESSES

CENTER FOR FIRE RESEARCH

FY-83

Professional Personnel

James Quintiere, Head

Howard Baum, Research Physicist

Dan Corley, Physicist

Margaret Harkleroad, Physicist

Ken Steckler, Physicist

Program Objectives

Hisahiro Takeda, Guest Worker

Yuji Hasemi, Guest Worker

Yogesh Jaluria, Summer Faculty (82)

Arvind Atreya, Summer Faculty (83)

Anil Kulkarni, Summer Faculty (83)

Through research we aim to develop predictive methods to describe the

comprehensive dynamics and elemental processes of fire growth within

and about compartment structures.

Scope

The work addresses fire growth within a single compartment, spread to the

adjoining space, and spread through a multi-compartment structure. It

examines the overall dynamics of the fire scenario and its elemental

processes such as ignition, flame spread, pyrolysis rate, extinction,

and the fire related transport processes. It utilizes mathematical

techniques, experimental studies and correlations, and similitude

methods to develop accurate predictions for realistic configurations

and materials. As appropriate, it formulates and demonstrates its

predictive methods for specific applications.

Pro j ect

1. Fire Generated Enclosure Phenomena

This is a joint project with the Center for Applied Mathematics.

Primarily it has sought to develop detailed predictions of phenomena

generated by fire in an enclosure. Specifically it has addressed the

flow field and smoke coagulation. This year it has achieved a notable

accomplishment; namely, transient three-dimensional results for fire

generated flows with particle tracking in a closed room (Figure 1)

.

Although computer resources still limit the easy execution and extension

of such computations, their potential applications, particularly illustrated through dynamic computer graphic display, have been demonstrated.

Related activities included the development of a smoke detector response

simulation, and improved numerical methods for fire applications.

15
Fire-Driven Buoyant-Flow Model

Heat Source

ngure j.. j-u isocnerns

Reports

1. Baum, H.R. and Rehm, R.G., "Numerical Computation of Large

Scale Fire Induced Flows", in Lecture Notes in Physics, Vol.

170, Springer Vertig, 3erlin, Heidelberg, N. Y., p. 124 (1982)

2. Baum, H.R., Rehm, R.G., and Mulholland, G.W., "Computation

of Fire Induced Flow and Smoke Coagulation", Nineteenth Svmp

.

(International) on Combustion , The Combustion Institute,

Pittsburgh, p. 921 (1982).

3. 3aum, H.R., Rehm, R.G., Barnett, P.D., and Corley, D.M.,

"Finite Difference Calculations of Buoyant Convection in an Enclosure, I. The Basic Algorithm", SIAM J. Sci. Stat. Comput.

4, p. 117 (1983).

4. Baum, H.R. , Rehm, R.G., and Mulholland, G.W., "Prediction of

Heat and Smoke Movement in Enclosure Fires", Proceedings,

Eighth International Conference on Problems of Automatic

Detectors, H. Luck, Ed., Univ. of Duisburg, p. 259, Oct 1982.

5. Rehm, R.G., 3aum, H.R. , 3arnett, P.D., Sweet, R.A. , O'Leary,

D.P. , and Corley, D.M., "Three Dimensional Computations of

Fire Induced Flow, - A Preliminary Report" 1982 Technical

Meeting, The Eastern Section of The Combustion Institute,

Dec. 14-16, Atlantic City, N.J.

6. 3eier, R.A. , deRis, J., and Baum, H.R., "Accuracy of Finite

Difference Methods in Recirculating Flows", Factory Mutual

Res. Corn. Report FMRC J.I. 0E0J4.BU, Sept. 1982.

7. 3aum, H.R. and Rockett, J., "An Investigation of the Forced

Ventilation in Containership Holds", NBSIR, May 1983.

16
2.

Flame Spread on Materials

Attention has been focused on the development of methods to predict downward or lateral spread rate, and upward spread rate on vertical materials

The opposed flow case has been studied for many materials, and a straight-forward procedure yields results for spread and ignition. From

these data phenomenological constants are deduced which enable predictions of material spread rate and ignition times in terms of irradiance.

Over thirty materials have been characterized. A typical result is

shown in Figure 2.

SHINGLE), ftSPHRLT Upward spread is being investigated by

measuring forward flame heat flux and

flame length beyond the pyrolysis zone

It is felt that this heat transfer

process is significant in upward

spread. To determine these data an apparatus has been constructed which

allows a 30 x 30 cm sample to bum

under externally radiated conditions.

The heat transfer from its extended

flame is measured to a water heated

plate by radiometers and total heat

flux sensors.

Figure 2. Ignition and Spread Rate

Reports

1. Quintiere, J., Harkleroad, M. , and Walton, D., "Measurements

of Material Flame Spread Properties", Comb. Sci. Technol. , 32_, 67 (1983).

2. Harkleroad, M. , Quintiere, J., and Walton, D., "Radiative

Ignition and Opposed Flow Flame Spread Measurements on Materials", FAA Report (in press)

3. Fernandez -P ello , A.C., and Quintiere, J., "A Simplified Model

of Radiating - Turbulent - Upward Flame Spread Over the Surface

of a Charring Combustible", 1982 Meeting, Eastern Section of

Combustion Institute, Atlantic City, Dec. 1982.

4. Baum, H.R. and Corley, D.M., "The Emmons Problem with External

Radiation, An Analytical Approach", Ibid.

17
3. Dynamics of Compartment Wall Fires

This project embraces three approaches to understanding the fire growth

on lining materials in compartments. In this problem the material and

its self-generated environment in the room interact. In one approach

a computer model attempts to simulate the fire growth on a wall of a room. The flame spread and pyrolysis rates are treated as functions of

incident radiative heat flux and local oxygen concentration. Many

aspects of the simulation model need to be refined and extended for the

model to be complete. To develop confidence in such models, a laboratory scale compartment experiment has been designed to study the

combustion of wall slabs. The time dependent burning rate of a PMMA

fixed area wall slabs shows a steady increase in mass loss rate over a significantly long period. Finally, as a third approach, the literature

on full-scale room lining material fires has been reviewed. The results

of the review suggest that low density (e.g. foam) materials with low

energy rates of combustion can yield extensive spread over room linings.

This may be due to their relatively more rapid opposed flow spread rates

than spread rates of more common (higher density) materials.

Reports

1. Steckler, K.D., "Calculations of Wall Fire Spread in an Enclosure", CSNI Specialist Meeting on Interaction of Fire

and Explosion with Ventilation Systems in Nuclear Facilities,

Los Alamos National Lab, Los Alamos, April 1983. (Also NBSIR

in press)

.

2. Quintiere, J., "Some Factors Influencing Fire Spread Over

Room Linings and in the ASTM E-84 Tunnel Test", (in review).

4. Fire Induced Flows

Over the last several years this project has focused on the measurement

of mass flow rates through door or window openings. These flows have

been generated by controlled steady-state fires within a room. The

experiments have been done at full-scale with fires of 30 to 150 kW.

In the last year line-fires against a wall have been studied. To date

the results have shown that vent flow coefficients are insensitive to

the vent geometry, fire size and fire configuration. However, theoretical results show that the flow coefficient, predicted from potential

flow analysis, agrees with the experimental results for the conditions

tested (0.62-0.72), but should increase to 1 as the opening size

approaches the wall area. With a knowledge of the flow coefficient it

is possible to estimate the vent flow rate from temperature measurements

alone, and this has been demonstrated in Figure 3 and exploited as a measurement technique. Using this method over 100 wall fire flows were

studied. Those data and associated estimates of mixing within the room

due to wall boundary layers and entrainment effects are being analyzed.

18
Figure 3. Mass flow rate derived from temperature data

Reports

1. Steckler, K. , Quintiere, J., and Rinkinen, W. , "Flow Induced

by Fire in a Compartment", Nineteenth International Symposium

on Combustion , The Combustion Institute, 1982, p..913, also see NBSIR 82-2520, Sept. 1982.

2. Jaluria, Y., "Buoyancy-Induced Wall Flow Due to Fire in a Room

NBSIR (in review) plus presentation at the 1982 Tech. Mtg.,

Eastern Sec. Comb. Inst., Atlantic City, N.J., Dec. 1982

3. Steckler, K. , Baum, H., and Quintiere, J., "Fire Induced Flows

Through Room Openings - Flow Coefficients", in review.

5. Fire Growth in Enclosures

This project deals with the general area of fire growth in compartments

Primarily it is based on the zone modeling concept which treats a room

fire in terms of discrete physical zones. The scope of activities has

ranged, from investigating an empirically derived formula to predict

temperature rise in a room fire, to developing a start at modeling fire

growth in multi-compartments. Literature results on fully-developed

compartment fires of wood cribs has revealed the prospect of highly

fuel rich fires (equivalence ratios in excess of 20) . These effects

must be understood to enable prediction of flame lengths for doors or windows. Currently we are studying the role of lining materials in

aircraft fires, and the early growth of fire due to blast effects.

19
ReDorts

1. Quintiere, J., "A Simple Correlation for Predicting

Temperature in a Room Fire", NBSIR, March 1983.

2. Tanaka, T., "A Model of Multiroom Fire Spread", NBSIR

(in press)

3. Quintiere, J. and Tanaka, T. , "Some Analyses of the FAA

Post Crash Aircraft Fire Scenario", Fire Technology , Vol. 19, p. 77, May 1983.

Grant Research

la. Harvard University, H. W. Emmons - "Compartment Fire Modeling".

lb. Factory Mutual Research, R. Friedman - "Flame Radiation and Pool

Fires".

2. Pennsylvania State University, G. Faeth - "Wall Fires".

3. California Institute of Technology, E. Zukoski - "Vent Mixing and

Gas-phase Flammability in Compartments".

4. Case-Western Reserve, J. Tien - "Flame Spread Limits"'.

5. Harvard University, G. Carrier and TRW, F. Fendell - "Wind-Aided

Flame Spread"

20
FIRE PERFORMANCE AND VALIDATION

FIRE MEASUREMENT AND RESEARCH DIVISION

CENTER FOR FIRE RESEARCH

FY 83

Professional Personnel

Sanford Davis, Head

J. Randall Lawson, General Physical Scientist

Billy T. Lee, Research Fire Prevention Engineer

Richard D. Peacock, Chemical Engineer

J. Samuel Steel, Physicist

Program Objectives

The objectives are to design and conduct tests to evaluate the

fire performance of systems, components, and structures and to

validate mathematical fire models.

Scope

This thrust includes two important efforts. First, the conduct of

unique, highly instrumented experiments to establish fire behavior on a realistic scale. Second, the conduct of validation programs in collaboration with other groups. This thrust provides particular expertise in

facility fire test experimental design, instrumentation, and data

processing and analysis.

Proj ects

1. Standard Room Fire Test

The objective of this project is to further develop the standard room

fire test for use by ASTM, with studies of fire spread and growth involving wall and ceiling finish materials when exposed to different

ignition scenarios. A secondary objective is to set up a quarter-scale

model of the test in order to (1) learn firsthand the problems which

might be encountered and to find workable solutions or necessary modifications to the proposed test method, (2) provide a data base for the

development and refinement of mathematical models which might be used

to predict the performance of materials in the standard room fire test,

and (3) evaluate the quarter-scale model room fire test as an interim

screening tool for use by industry.

Room fire tests of several materials having a wide range of fire properties have been conducted under three different ignition exposures. In

these tests, the test material fully lined three walls and the ceiling.

21
For some materials, the room fire development rate was found to be a strong function of the ignition exposures considered. Fire tests with

the same materials lining only the walls or just the ceiling will be

performed next. Quarter-scale tests of these same materials will be

carried out also

.

Lee, B.T., Quarter-Scale Modeling of Room Fire Tests of Interior Finish,

Nat. Bur. Stds. NBSIR 81-2453, March 1982.

2. Validation of Fire Models

With increased activity in the development of analytical models for the

description of fire growth processes and other fire-related phenomena,

there is a need to develop a systematic approach to determine what con- stitutes validation of these models. The validation of any model aims

at demonstrating that the model bears a close resemblance to the system

being modeled.

Basically, model validation involves two kinds of concerns: technical

and operational. Technical validation deals with identifying all the

assumptions, variables, and relationships used in relating the model to

the real world, problems of the accuracy of the input data, the correctness of mathematical and numerical calculations, and agreement between

the model and the observed outcomes. Operational validation appraises

the importance of the errors and divergences found under technical

validation. It is concerned with whether or not the model can produce

bad answers for proper ranges of parameter values and includes sensitivity analysis.

The entire process of model validation is dynamic. As theoretical

insights, computational and instrumentation capabilities improve, it is

desirable to re-examine existing models to determine if they remain

valid in the light of these improved understandings.

Accordingly, this Fire Model Validation project, initiated in FY 83,

will be an ongoing process. In order to set up the mechanisms for

determining to what extent validation has been achieved, there is a need for mathematics capability not yet applied to this situation. A

joint program with the Center for Applied Math has been developed and

the project has begun with the choice of an appropriate operational

model for which suitable validation experiments can be devised. The

protocols are being developed for a series of full scale fire experiments, including the statistical design of the conditions for the

trials and the frequency and types of data to be collected. The methodology ultimately will be developed for determining when the predictions

of the mathematical model and the data from the full scale fire ex- periments agree closely enough to constitute validation.

22
3. Fire Safety Aspects of Wood as a Fuel

The objective of this project is to study the hazards associated with

the installation, operation, and maintenance of wood-burning appliances

used for space heating in single-family dwellings and similar smallscale applications. The overall research program included (1) a survey

of fire incidents involving wood-burning appliances, (2) a review of

codes and standards dealing with solid-fuel appliances, and (3) experimental studies to develop information in the areas of clearance to

combustibles, chimney creosoting and chimney fires, fireplace inserts,

and products of combustion.

Items (1) and (2) have been completed and show wood heating as a major

cause of fire in the United States. In 1981, one in every five or six

fires in residential property were caused by such appliances. A report,

"Intensity and Duration of Chimney Fires in Several Chimneys" will be

published shortly, detailing our studies in chimney creosoting and

creosote burnouts. The report presents data showing temperature levels

during chimney fires higher than current testing standards specify.

Current studies are directed towards evaluating proper techniques for

connecting appliances to masonry chimneys through combustible walls.

A report entitled "Wall Protection Systems for Wood Heating Appliances"

was published in 1982 describing the results of tests to investigate

alternative methods to reduce clearances between heat producing appliances and combustible materials.

A newly revised code for installation of solid fuel appliances incorporating the results of these research efforts should be published in

early 1984.

Loftus, J.J., Evaluation of Wall Protection Systems for Wood Heating

Appliances, Nat. Bur. Stds. NBSIR 82-2506, May 1982.

4. Solar Collector Fire Assessment

The objective of this program is to evaluate a method for determining

the propensities of materials (used in the fabrication of solar heat

collectors) to self heat after exposure to elevated temperatures for

extended periods of time. A total of eight different urethane foams

plus exterior grade plywood, untreated and retardant created, are being subjected to adiabatic furnace tests; activation energies are determined for each of the materials. Temperatures found to start the

self-heating process will be compared with data in the literature and

available field experience on the effects of long-term heating on material fire properties. Calculations of critical size for a material

can be made if specific heat and thermal conductivity values are known.

Test results will be tabulated so as to be useful to designers or solar

collectors

.

23
5.

Fire Performance Testing of Walk-on Platforms of the VA Hospital

Building System

The objective of this project is to evaluate the fire resistive properties of building materials and construction systems proposed for use in

VA medical facilities. The VA Building System concept incorporates an interstitial space with a walk-on ceiling platform between each functional floor of a hospital building. These systems are designed to

provide a fire endurance of two hours between patient floors. A threelevel steel frame representing a portion of a mid-rise building serves

as the test structure. The walk-on platforms are built into the secondlevel of this structure and they are exposed from below to a fire which

follows the ASTM E 119 time- temperature curve. Temperature measurements

are made throughout the structure by 136 thermocouples.

In addition to the tests, a computer model is being used to simulate

the fire performance of the building systems. Data from the tests are being compared to the calculated values in an attempt to further validate the computer model.

6.

Fire Safety of Amtrak Passenger Car Interior Furnishings

The objective of this project is to develop and test cost beneficial

concepts for reducing fire hazards in passenger rail vehicles. Fullsize mock-ups of vehicle interiors have been tested with different

combinations of materials currently under consideration for use as seating, wall covering, floor covering, window masks, and window

glazing.

laboratory-scale testing of the individual materials compliments the

full-scale test program. A comparison of the laboratory-scale tests

and the full-size mock-up tests shows that while the laboratory-scale

tests are able to predict the effects of material changes in the same geometric configuration, they cannot predict effects due to changes in

geometry in the full-size mock-up tests. A report entitled "Fire Tests

of Amtrak Passenger Sail Vehicle Interiors" will be published shortly.

7.

Fire Test Standards

The objective of this project is to support CFR's participation in the

maintenance of existing and proposed voluntary consensus standard test

methods. To accomplish this objective, CFR works closely with the

various consensus standard groups and responds to the need for research

for the solution of technical problems related to fire test methods.

Work has continued on the evaluation of pilot burners for the ASTM E 162

surface flammability test. Results of the study are being submitted to

the ASTM Committee and other laboratories are conducting compartive investigations. The development of the ease of ignition by flame exposure

test for vertically oriented interior finish materials has continued.
The improvements identified during the preliminary round robin carried

out on the test method have been incorporated into the test procedure.

An interlaboratory test program is currently underway to evaluate the

revised test procedure. In addition, other ASTM and NFPA standard

tests are being reviewed to identify potential areas where improvements may be realized.

CFR has cooperated with the National Voluntary Laboratory Accreditation Program (NVLAP) on the evaluation of test results from various

fire test proficiency test programs in an attempt to identify possible

causes of variation noted from some data. The flooring radiant panel

test for carpet and for attic floor insulation and the smoldering com- bustion test for insulation have been the main subjects for discussion.

Lawson, J.R. and Parker, W.J., Development of an Ease of Ignition Test

Using a Flame Exposure, Nat. 3ur. Stds. NBSIR 82-2503, June 1982.

3. Consensus Guinalme ror Arsen Accelerant Analysis

An ad hoc working group of competent forensic laboratory personnel

has been working with NBS personnel on the development of a consensus

standard for forensic laboratories to use in the recovery and analysis

of accelerants in samples from suspected arson fires. Two interlaboratory programs have been carried out in the recent past. Based on the

complete analysis of the second (more extensive) program, a revised

draft standard will be prepared for submittal to NFPA.

9. Large-Scale Fire Research Facilities

The large-scale testing facilities at the Gaithersburg site are available for use by CFR programs as needed. 3uilding 205 is a 60-ft by

120-ft test building with controlled environmental conditions; a large

smoke collection hood serves the individual experimental facilities

and is connected to a large stack with afterburner. Building 205 also

houses special calorimeters tor measuring rate of heat release, pilot

furnaces, and reduced-scale model enclosures. Of particular interest

has been the development of a calorimeter for measuring the rate of

heat release from full-size items of furniture; this provides a means

for determining input data for analytical models. Laboratories are available for toxicology studies in conjunction with large-scale fire

experiments. A new room/corridor facility has been constructed recently

for studying smoke and toxic gas transport phenomena. In addition, we

are in the process of up-grading the data acquisition system to provide

increased scanning speeds, improved reliability, and real-time graphics

display during the course of the test. The NBS Annex is a former DOD

facility adjacent to the NBS site, which is available for special tests.

Associated Grants

University of Notre Dame, Murtv Kanury - "Scaling Correlations of Flashover Experiments."

25
FIRE RESEARCH INFORMATION SERVICES

OFFICE OF FIRE RESEARCH RESOURCES

CENTER FOR FIRE RESEARCH

FY 83

Project: Leader

Nora H. Jason

Program Objective

The Fire Research Information Services (FRIS) is an on-going project

within the Center for Fire Research (CFR) , National Bureau of Standards.

It was started in 1971 and incorporated several personal collections at

the National Bureau of Standards, as well as the Federal Fire Council

collection. Over the years it has grown and now contains approximately

30,000 reports, documents and books. (On an average, 1500 items are added to the collection each year.) It reflects the programmatic needs

of the Center for Fire Research, as well as developing a national and

international fire research collection for use by NBS staff, researchers,

fire departments, fire science students and the fire community at large.

An extensive document distribution program is carried on, both on a regular basis and on a demand basis. The publication and distribution

of grantee reports (in the NBS Government Contract Report series) to

selected subject interest groups is part of this program.' All NBS

report series are listed in the automated bibliographic data base and

available through the Government Printing Office of the National

Technical Information Services.

The journal collection contains approximately 100 titles. The focus is on the research activities of the CFR, as well as fire-related research

needs. The titles are quite unique to FRIS.

For interested people who cannot come to the FRIS, an extensive interlibrary loan program is carried out with participating libraries

throughout the United States. FRIS is located at the National Bureau

of Standards, Building 224, Room A-252. The telephone number is

(301) 921-3249.

26
FIRE RISK ANALYSIS

FIRE SAFETY TECHNOLOGY DIVISION

CENTER FOR FIRE RESEARCH

FY 83

Professional Personnel

Alan Gomberg, Head

S. Wayne Stiefel, Operations Research Analyst

John R. Hall, Jr., Operations Research Analyst

Kwan-nan Yeh, Operations Research Analyst (IPA)

Program Objectives

The primary objective of the Fire Risk Analysis Group is the development

of quantitative means to measure and manage fire risk to people, property, or systems from various specified factors for use by specified

decision makers. A secondary objective is to provide access to, and

analysis of, fire loss data for CFR.

Scope

Since fire and fire loss/cost are random events the desired measures

involve probability statements and stochastic processes and their linkage

to deterministic models. Estimates of risk are to be specified in terms

such as likelihood of occurrence and outcome measures and involve present

(i.e. actual or known) or future (i.e. presumed) situations, designs,

materials, procedures, behavior, regulatory requirements, decisions,

etc. The tools developed in this thrust are intended for use by code or regulatory officials, policy-makers, corporate managers or others.

Proj ects

1. Risk Assessment

This project area focuses on the development of risk assessment tools

and methodologies to enable users to perform risk management functions.

Emphasis is on developing risk estimation methods that can interact in a comprehensive approach to fire risk assessment. Current efforts in this area include the development of a risk assessment based management

system to assist in the allocation of fire safety project funds in

national park facilities, design and testing of an overall framework for

risk assessment, modeling of ignition risk in buildings, and development

and testing of a risk assessment methodology for nuclear facilities.

2. Decision Analysis

Decision on the choice between strategic alternatives for reducing fire

losses should be based on a systematic consideration of all benefits,

risks and costs. We have developed analytical techniques for assessing

the risks and benefits associated with different fire safety alternatives.

27
and the economic costs of these alternatives. Decision analysis provides

the analytical framework for combining these loss and cost assessments

and determining how sensitive the resultant cost effectiveness is to the

variables. The initial decision analysis study of alternatives for the

reduction of upholstered furniture fire losses served to establish the

utility of this approach for fire hazard applications. A major decision

analysis study is now nearing completion on the residential fire problem,

to compare alternatives such as smoke detection, sprinklers, and "fast

response" sprinklers on a cost /benefit basis.

Decision analysis techniques are being used to develop a risk based

evaluation system for commercial aircraft fire safety alternatives, with

the initial effort focusing on the effect of seat blocking in survivable

crash fires. Decision analysis is also being applied in other fire

safety areas including health care facilities and arson.

Clark, L. ?. , A Life-Cycle Cost Analysis Methodology for Fire Protection

in New Health Care Facilities, Nat. Bur. Stds. , Rent. NBSIR 82-2558

(1982)

.

Gomberg, A., 3uchbinder, B. , and Offensend, F. J. , Evaluating Alternative

Strategies for Reducing Residential Fire Loss - The Fire Loss Model,

Nat. 3ur . Stds., Rept. NBSIR 82-2551 (1982).

Stiefel, S. W. , Use of Decision Analysis in Arson Program Planning, Nat.

3ur . Stds., Rept. NBSIR 82-2596 (1982).

3. Special Studies

Using the National Fire Incident Reporting System and other data, we perform special studies to characterize specific fire hazards. Current

special study topics include the following:

- Identification of factors associated with high fire death rates

in rural areas and certain geographical areas.

- Analysis o f electrical fire investigation data to establish key

electrical fire causal chains and possible intervention strategies.

- Assessment of potential cost effectiveness of residential

sprinkler systems and development of methods to improve sprinkler

cost effectiveness.

- Identification of the nature and magnitude of fireplace and space

heater fire problems in mobile homes.

Gcmberg, A., and Clark, L. ?., Rural and Non-Rural Civilian Residential

Fire Fatalities in Twelve States, Nat. 3ur. Stds. , Rept. NBSIR 82-2519

(1982)

.

23
Gomberg, A., and Hall, J. R. , Space Heater - Rural Death Link, Fire

Service Today, Vol. 49, No. 9, 18-21, September 1982.

Gomberg, A. and Hall, J. R. , Analysis of Electrical Fire Investigations

in Ten Cities, Nat. Bur. Stds. , Rept. NBSIR 83-2677 (1983).

Associated Contracts

1. SRI International, Fred L. Offensend - "Continuation of Decision

Analysis Studies in Fire Hazard Analysis".

2. Center for Applied Mathematics, National 3ureau of Standards - "Economic Analysis of Residential Automatic Sprinkler Systems".

3. Center for Applied Mathematics, National Bureau of Standards - "Expected Utility Theory for Selecting Fire Mitigation Strategies".

29
FIRE SUPPRESSION AND EXTINGUISHMENT

FIRE SAFETY TECHNOLOGY DIVISION

CENTER FOR FIRE RESEARCH

FY 83

Professional Personnel

Edward K. 3udnick, Head

David D. Evans, Mechanical Engineer

Warren D. Hayes, Fire Prevention Engineer

3emard J. McCaffrey, Mechanical Engxneer

James A. Milke, Fire Protection Engineer (Part time)

Richard H. Zile, Engineering Technician

Program Objectives

The principal objective of this research group is to establish a basis

for the technologies of extinguishment and suppression of fire processes

through development of an understanding of how flames and smoldering are quenched, development of means to evaluate the effectiveness of materials

or svstems designed for this purpose, and development of performance

data and test methods.

Scop e

This effort involves studies of the basic phenomenology of extinction,

studies of model systems, and mechanical testing of realistic configurations. The thrust involves fundamental studies, mathematical and com- puter models, and substantial experimental and laboratory effort.

Principal emphasis is upon solid fuels, although gases and liquids will

be included. The work treats both smoldering and flaming combustion and

includes liquid, gaseous and solid powder suppressants. Suppression and

extinguishment mechanisms are considered at all phases of the fire

development process. Integrated results should be sufficient to serve

as technical basis for advancing the state of engineering practice in

the development, design, selection, and performance evaluation of a wide

variety of types of fixed or portable extinguishment /suppress ion systems.

Projects

1. Prediction of Thermal Activation Conditions in Enclosures

Theoretical and experimental efforts are being combined in order to

develop a means of predicting temperature and velocity conditions near

the ceiling and upper walls in compartments. Accurate predictions of

these conditions are necessary to provide the basis for engineering

models designed to identify optimum siting locations for thermally

activated suppression systems. Initial work involved full-scale and

laboratory scaled experiments to provide a basis for calculations and

scaling methods for simple, axisymmetric geometries. Initial results of

this work indicate that accumulated hot gas layers significantly affect

30
temperatures in the ceiling jet flow in small compartments. Therefore,

in order to predict flow temperatures with sufficient accuracy to be

meaningful in developing predictive methods for activation of thermal

devices, a means of accounting for the plume flow in a two layer system

was developed. In 1983 work involved modification of existing methods

to develop both an exact mathematical solution and an approximate method

for correction of plume temperatures due to the influence of the heated

upper layer. Good agreement was obtained between calculations and

controlled experimental measurements for ceiling impingement temperatures,

and temperature and velocity conditions along the ceiling. Work will

continue in 1984 to extend the model to more complex geometries, and to

attempt to predict conditions at the wall-ceiling juncture, a common

location for sprinkler installation.

Evans, D. and Madrzykowski , D. , Characterizing the Thermal Response of

Fusible-Link Sprinklers, NBSTR 81-2329, August 1981.

Evans, D. , Plume Flow in a Two-Layer Environment, paper presented at

ASME-AIChE National Heat Transfer Conference, Seattle, Washington, July

1983.

Evans, D. , Sprinklers Come Home at Last, Fire Service Today, Vol. 49,

No. 10, October 1982.

2. Fire Plume Characterization

The prediction of the burning rate of materials in a pool configuration

remains one of the outstanding problems of fire research. To this end,

measurements of gas velocity, temperature and chemical species concentrations are being made in the near field of buoyant diffusion flames.

Together with measurements of both total and radiative heat flux back to

the burning surface, as well as to distant targets, analytical representations of the phenomena are being developed.

It is realized that the plume is not well-mixed, and that it is highly

likely that the flame-determining physics and chemistry are dominated by

the local fuel-air ratio. Thus we are in the process of determining the

fluctuation magnitudes and frequency distribution of the temperature and

reactant concentrations in turbulent plumes.

McCaffrey, B., Momentum Implications for Buoyant Diffusion Flames,

Combustion and Flame, 1983.

3. Measurement of Suppression Agent Plume Penetration

Important elements in determining the effects of suppressants on burning

fuels are the amounts and rates of the agent which reach the burning

surfaces of the fuel. The buoyancy forces of the heated plume above

fires of various sizes are being examined experimentally to determine

the effects on the agent penetration to the burning surface. As an initial effort, an apparatus has been constructed to provide such

31
measurements for water sprays. Initial experiments with monodisperse

sprays of known droplet sizes have been completed. Work will be continued

in 1984 in order to develop a correlation for effects of fire size on water spray penetration to burning fuels, leading to an empirically

based method for optimization of water sprays for extinguishment.

4. Measurement of Agent Effect on Solid Fuels

A study was initiated in 1983 to examine the thermal effects of known

quantities of suppressants on burning solids. The primary focus in 1983

has been the design of an experimental apparatus that would provide

baseline measurements for well characterized water sprays and simple

fuel arrays. This effort will be continued in 1984 in order to establish

baseline information necessary to pursue the development of a first cut

model for suppression effects on solid fuel combustion.

5. Suppression Systems for Offshore Platform Blowout Fires

The primary objective of this multi-year project is to demonstrate the

feasibility and provide engineering guidelines regarding the extinguishment of hydrocarbon fires resulting from gas and oil well blowouts by

water spray. Blowout fires with heat release rates on the order of 1000

MW may be expected.

All laboratory work in 1983 has been directed at developing an understanding of the cooling and extinction of turbulent methane diffusion

flames with water sprays. Laboratory work has been at heat release

rates on from 1 to 10 MW. Based on these experiments, scaling parameters

will be established and an effort will be made to predict the result at

approximately 200 MW, or one-fifth the actual scale anticipated. Validation of the prediction of 200 MW will then be performed.

Evans, D. , McCaffrey, B., Control of Blowout Fires with Water Sprays,

Proceeding of Outer Continental Shelf Oil and Gas Operations, Technical

Report, 1983.

Evans, D. O’Neill, J., Feasibility Study of Extinguishing Gas Well

Blowout Fire with Water Sprays, NBSIR, (in review).

McCaffrey, B. , Jet Diffusion Flame Suppression Using Water Sprays,

NBSIR, 1983.

Associated Grants

1. Case Western Reserve University, Joseph M. Prahl - "Experimental

and Analytical Study of Fire Sprinkler Scaling Laws".

2. Factory Mutual Research Corporation, Ronald Alpert - "Calculated

Interaction of Water Droplet Sprays with Fire Plumes in Compartments".

32
FIRE TOXICOLOGY

FIRE MEASUREMENT AND RESEARCH DIVISION

CENTER FOR FIRE RESEARCH

FY 83

Professional Personnel

Barbara C. Levin, Head

Maya Paabo, Research Chemist

Cheryl Bailey, Research Chemist

Joshua Gurman, Research Associate, American Iron and Steel Institute

Steven E. Harris, Guest Worker, University of Pittsburgh

Program Objective

To identify potentially harmful combustion products and measure their

effect on living organisms.

Scope

This thrust determines composition of potentially toxic combustion

products under different fire exposures, establishes the physiological

effects of such products, and provides measurement methods.

Projects

1. Toxicity Test Method Development

The current version of the NBS toxicity test method, which was developed

to assess the acute inhalation toxicity of combustion products, has

certain limitations with regard to the combustion system. A new com- bustion system has been designed and is a modification of the cone calorimeter developed by V. Babrauskas to measure rate of heat release.

This new radiant energy system will permit the evaluation of materials

in both a vertical and horizontal orientation. The evaluation of

composite materials will allow the surface normally exposed in a real

fire to be exposed to the heat source first. In addition, the continuous mass loss of the material during the thermal decomposition and the

oxygen (0^) levels both at the site of combustion and in the exposure

chamber will be measured. Control of the 0^ levels at both sites will

now be possible.

Levin, B.C., Fowell, A. J. , Birky, M.M. , Paabo, M. , Stolte, A. and Malek,

D. , "Further Development of a Test Method for the Assessment of the

Acute Inhalation Toxicity of Combustion Products," Nat. Bur. Stds.,

NBSIR 82-2532, June 1982.

Snell, J.E. , Levin, B.C. and Fowell, A.J. , "Workshop on Combustion

Product Toxicity, Summary of Presentations, September 10, 1982," Nat.

Bur. Stds., NBSIR 82-2634, November 1982.

Levin, B.C., "Toxic Gases and Fire Deaths," Nature 300:18 (1982).

33
Levin, 3.C., Paabo, >1. , Birky, M.M. , ''An Interlaboratory Evaluation of

the 1980 Version of the National Bureau of Standards Test Method for

Assessing the Acute Inhalation Toxicity of Combustion Products," Nat.

Bur. Stds . , NBSIR 83-2678, April 1983.

Levin, B.C., "The National Bureau of Standards Toxicity Test Method,"

Proceedings of the Flame Retardant Chemical Association, March 22-24,

1983, Baltimore, Maryland. In press.

2. Toxicity of Flexible Polyurethane Foam With and Without Flame

Retardants and a Polyester Fiberous Filling Material

This study is being performed for the Consumer Product Safety Commission

who provided the Fire Toxicology Group with five samples of upholstered

furniture filling materials. Two different formulations of flexible

polyurethane foam were treated with different flame retardants and both

treated and untreated samples were tested according to the NBS toxicity

test method. In addition, a polyester fiber is also being evaluated.

The addition of the flame retardants did not significantly change the

autoignition temperatures of the polyurethane foam samples. Most of the

animal deaths occurred during the 14 day post-exposure observation

period, although a few were noted during the 30 minute exposure. This

study is nearing completion and the final report will be ready in

September.

3. Conditions Conducive to Hydrogen Cyanide Generation from Flexible

Polyurethane Foam (GM-21)

Large-scale room burns of both flexible polyurethane foam slabs (GM-21)

and polyurethane chairs showed that increased concentrations of hydrogen

cyanide (HCN) were generated when the samples burst into flames after an earlier smoldering period. These levels of HCN were not observed in

small-scale tests performed 25°C above (flaming) or 25°C below (nonflaming) the autoignition temperature of this flexible polyurethane foam

(GM-21)

.

An attempt was made to simulate the large-scale conditions in the

laboratory as follows. First, the material was exposed to a temperature

25° C below its autoignition temperature for 15 minutes, then the residue was heated at an elevated temperature. Flaming was not observed;

however, the HCN levels increased tenfold. Further experiments indicated that only exposing the material to the higher temperatures did not

produce the HCN, but rather a two step process was involved. First, the

material was charred under the non-flaming conditions and then the char

had to be heated. The HCN levels were related to the amount of char

formed. A flame retarded polyurethane foam (GM-24) produced twice as much char and twice as much HCN. Elemental analysis indicated the

concentration of nitrogen increased about 3 fold in the char when com- pared to the virgin foam whether the foam was flame retarded or not.

Work is progressing on determination of the chemical or physical mechanism which is responsible for this increased cyanide production.

34
Alarie, Y., Stock, M.F., Matijak-Schaper, M. and Birky, M.M. , "Toxicity

of Smoke During Chair Smoldering Tests and Small Scale Tests Using the

Same Materials," Fund, and Appl. Toxicology, in press.

Braun, E. , Krasny, J.F. , Peacock, R.D. , Paabo, M. , Smith, G.F. - , and

Stolte, A., "Cigarette Ignition of Upholstered Chairs," J. Consumer

Product Flammability , 9_:167 (1982).

4. Pure Gas Studies

The purpose of these studies is to accummulate baseline data to determine

if toxicity can be equated with discrete gas concentrations produced in

typical fires. To date, results from pure carbon monoxide studies

performed in the exposure chamber (described in the NBS toxicity test

method report, NBSIR 82-2532) indicated that an average concentration of

5000 ppm over 30 minutes was necessary to kill half of the test animals

(rats) . The carboxyhemoglobin (COHb) levels necessary for death to

occur were 87-89%. Preliminary results indicated that adding sublethal

amounts of CO- to previously determined non-lethal concentrations of CO

resulted in 4/6 of the animals dying. These animals had COHb levels of

84% which correlated well with previous results on CO and COHb. These

studies provided information on both formation of COHb during exposure

and reduction following removal of the animals from the test atmosphere.

Recovery from these high levels of COHb appeared to be very rapid.

(%C0Hb dropped from 84% to 40% in less than 15 minutes.) An examination

of CO and COHb levels generated at the LC^ concentrations for 30 minutes

calculated for the materials studied during the interlaboratory evaluation

indicated that the COHb levels for some materials were lower than expected.

These materials all contained nitrogen and produced hydrogen cyanide

upon thermal decomposition. The additive effects of these two toxicants

(CO and HCN) appear to account for most of the deaths observed in these

experiments.

Associated Grants

1. University of Pittsburgh, Yves Alarie, "Toxicity of Plastic Combustion

Products.

2. Colorado School of Mines, Kent Voorhees, "Characterization of Aerosols

from Fires."

3. Southwest Research Institute, Gordon Hartzell, "Analysis of Hazards

to Life Safety in Fires."

35
MATERIALS FIRE PROPERTIES

FIRE MEASUREMENT AND RESEARCH DIVISION

CENTER FOR FIRE RESEARCH

FY 83

Professional Personnel

Vytenis Babrauskas, Fire Protection Engineer, Acting Head

Emil Braun, Physicist

Zhanxian Han, Guest worker

John Krasny, Textile Technologist

Joseph Loftus, Research Chemist

William Parker, Physicist

Program Objectives

The objectives are to develop and validate measurement methods and to

generate data necessary to characterize the fire performance of materials

and products in engineering applications or for use in the modeling of

fires.

Scope

This thrust involves significant effort in materials science, measurement technology development, and experimental work covering the behavior

and response of materials to the range of energy sources encountered in

incipient and fully developed fires. Materials include single substances

and combinations. Test methods relate to actual materials and realistic

configurations and conditions and cover a variety of scales from bench

to full-scale.

The outputs from this thrust represent crucial inputs to the fire

processes and other modeling activities of the fire protection engineering

thrusts of the Center. Therefore, very close coordination with these

thrusts is required in establishing clear definition of key technical

parameters, their means of measurement, the kinds of data collected, and

relative priorities among the test method development and data generation

elements of this thrust.

Pro j ects

1. Development of the Cone Calorimeter

During the past year the construction was finished on the cone calorimeter

which is a new bench-scale rate of heat release calorimeter using the

oxygen consumption principle. A report giving construction details and

calibration results was issued. Since the instrument is intended

primarily for measurements on commercial products, including composites,

a test standard based on this instrument was proposed to Committee E-5 of

the ASTM, where a task group was formed to investigate its standardization

This instrument has enabled us to gather, at much less cost, the type of

information for which the NBS-II calorimeter has previously been required;

36
furthermore, the rate of heat release curves show substantially less

noise, in comparison. On-going work includes the development of instrumentation for suitable real-time measurements of additional important

gas species and particulate measurements.

Babrauskas, V. , Development of the Cone Calorimeter — A 3ench-Scale Heat

Release Apparatus Based on Oxygen Consumption (NBSIR 82-2611). Nat.

Bur. Stand. (1982).

2. Upholstered Furniture Burning Rates

An extensive series of furniture calorimeter bums had been completed in

the prior year; a report and a journal article documenting these findings

were recently published.

During the past year work was finished on mockup flame spread testing

and the data were analyzed. This arrangement involved full-sized chair

assemblies using steel frames but realistic cushions. The primary

objective was to obtain a quantitative data base on flame spread rates.

A major finding was that the flame spread rates could be well correlated

to trip-thread burn-through times and to the times required to reach a 100 kW burning rate, both substantially easier to measure variables.

Work continued on the bench-scale (cone calorimeter) measurements of

heat release and on the correlation of these to full-scale values. This

was done for both the real furniture test series and for the mockup test

series. Conditions of 25 kW/m” irradiance and 180 s averaging time were

found to give the best predictability. The approximate heat release

rate estimating rule first proposed as part of the analysis of the

furniture calorimeter tests has now been extended to include appropriate

bench-scale data from the cone calorimeter.

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). Nat. Bur. Stand. (1982).

Babrauskas, V. , Upholstered Furniture Heat Release Rates: Measurements

and Estimation, of_ Fire Sciences . 1_, 932 (Jan/Feb 1983) .

3. Flame Spread

Flame spread rates are an important hazard aspect for furniture and other

combustibles. Upholstered furniture presents some unique measurement

problems since typically multiple, but not bonded, layers of materials

are present. This has generally precluded their testing in generalpurpose flame spread apparatuses. An apparatus designed especially to

avoid some of these problems was recently calibrated and placed into

operation. It includes a fabric hold-down mechanism and involves linear

spread, against the wind, on a horizontal (face up) specimen being

heated by uniform external irradiation. A narrow-angle radiance meter

and a two-color pyrometer have been provided to enable measurements of

average flame radiation properties. The results will be analyzed

37
according to the theory of radiatively-driven flame spread, with special

emphasis on measurements of the flame flux.

4. Heat Release Rate of Char Forming Materials

A model is being developed for the heat release rate of char forming

materials as a function of their chemical, thermochemical, and thermophysical properties along with their exposure and boundary conditions.

It is a theoretical and experimental program devoted initially to woodbased materials. It is intended to predict the results of the various

heat release rate calorimeters being considered for national and international tests and thus explain their differences in their reported data

in terms of operational, instrumental, and specimen size and orientation

variations. More importantly such a model is needed to couple the flame

spread and fire growth models which have been successful for simple

materials such as PMMA to more complex cellulosic materials for which a constant effective heat of vaporization does not apply. The model has

to treat the external radiation and flame heat transfer to the surface

as well as the internal heat transfer and pyrolysis. The work draws

from the large amount of work already in the literature on flame spread,

flame radiation, pyrolysis and charring rates. As a starting point, the

thermophvsical properties as a function of temperature and degree of

char are being obtained to check out some of the existing mass loss rate

models. However, it is not sufficient to merely predict the mass loss

rate since the chemical composition of the volatile pyrolysis products

changes during exposure. It is essential to individually account for

the mass release rates of H, C, and 0 in order to predict the heat

release rate. This requires the postulation of a pyrolysis mechanism.

The effect of fissuring due to char consolidation on the heat transfer

must also be taken into account.

5. Solar Glazing Flame Spread Performance

Solar collector glazing materials are often combustible. Their roof

mounting makes them particularly vulnerable to fire spread, thus it is

important that they not be easily ignitable from flying brands and that

flame spread, if started, be slow. To determine this, a number of

typical solar glazing plastics have been tested in both small-scale

tests for flame spread and in full-scale exposures. Analysis is now being done to lead to a recommendation to the Department of Energy on appropriate bench-scale tests.

Associated Grants

1. Brown University, Merwin Sibulkin - Study of Effects of Material

Properties on Flaming Combustion of Charring Fuels.

2. Factory Mutual, A. Tewarson - Determination of Fuel Parameters for

Fire Modeling.

University of Michigan, George Springer - The Behavior of Furniture

Frames During Fire. 30

3 .
SMOKE AND TOXIC GASES

FIRE SAFETY TECHNOLOGY DIVISION

CENTER FOR FIRE RESEARCH

FY-83

Professional Personnel

Richard W. Bukowski, Head

Walter Jones, General Physical Scientist

John Klote, Mechanical Engineer

George Mulholland, Research Chemist

Program Objectives

To provide an understanding of the rate of production, properties, and

spread of smoke and toxic gases from fires and the technical basis for

control of these products to enable reduction of their harmful impacts,

particularly on people in fire situations.

Scope

This thrust covers control of smoke and toxic gases in and around

facilities involved in fire. It includes the studies of the properties

of combustion products and entrained materials and the effects on a facility and its occupants. It includes the development of models of

smoke generation and transport in facilities, development of quantitative

means to assess the impact of smoke and toxic gases under assumed fire

and occupant conditions in specified facilities; and models for the

development and performance evaluation of alternative strategies or technologies for smoke control, for detection and communication systems

design, and for predicting available egress times for occupants.

Pro.j ects

1. Toxic Hazard Assessment

The toxicity of combustion products is possibly the most debated topic

of fire research today. Toxicity test methods are being developed by a number of groups. But toxicity is only one aspect of the hazard to

people from a fire and is not always the dominant factor. This project

was established to develop a method by which a quantitative evaluation

of occupant hazard can be obtained including the relative contribution

of toxicity, ignitability , rate of heat release, building design, fire

protection features, and others. The project will take advantage of

the advances in computer fire modeling and graphics display over the

past decade as the core of this method. The resulting model can be

used to assess the hazards presented by specific materials and assemblies, the relative value of materials with modified properties, and the

counterbalancing effects of protection systems in hazard reduction.

39
2.

Smoke Transport Modeling

This is one of the primary subtasks of the toxic hazard assessment project

and involves the development of efficient and accurate models to predict

the spread of smoke and gases in a building. While this model, as most

others currently available, is a zone model, it differs from many in

two major ways. First, considerable effort has been put into the

numerical implementation and solution to the equations to improve speed

and minimize the convergence problems common to the other models.

Second, this model retains the transient pressure term which most other

models disregard. Such a formulation gives the model increased flexibility by allowing for unvented enclosures and pressure related effects

such as flame puffing. Verification of these models is an ongoing process. Validation of these models is particularly important if the

toxic hazard assessment protocol is to be included in a credible way.

Jones, W. , "A Review of Compartment Fire Models", NBSIR 83-2684 (1983).

Jones, W. and Quintiere, J., "Prediction of Corridor Smoke Filling by

Zone Models, to be published in Combustion Science and Technology.

3 . Computer Graphics

The purpose of this project is to develop the hardware and software

capabilities necessary to input the geometry and arrangement of a large

structure into a computer and to display the massive amount of data

produced by the models in a manner which is relatively easily understood and assimilated. We are working with the state-of-the-art high

resolution color graphics equipment and developing animation techniques

to show smoke spread in real time with 3 dimensional isometric views

of these structures.

Jones, W., "Use of Graphics in Modeling Building Fires", Invited paper

to be given at the Perkin-Elmer Users Group Meeting, October 1983.

4. Smoke Dynamics in an Enclosure

For several years, CFR has been developing a field model of plume

dynamics in an enclosure. This model is now performing 3 dimensional

calculations of the spatial distribution of products including particle

tracking and coagulation. The purpose of the smoke dynamics project

is to conduct experimental verification of these field model predictions

by developing a half-scale, air-tight test enclosure, well characterized

aerosol/plume source, and fast response gas and particle instrumentation

capable of localized, in situ concentration/size measurements.

3aum, Rehm, and Mulholland, "Prediction of Heat and Smoke Movement in

Enclosure Fires", Proceedings of the Eighth International Symposium on Problems of Automatic Fire Detection. Duisburg, W. Germany, Oct. 1982.

Mulholland, G., "How Well Are We Measuring Smoke?", Fire & Mat., 6, 65.

40
5.

Smoke Production

This project is an attempt to include soot particle formation and growth

in a first order model for smoke production from materials. This first

order model will provide insight into the most important measurement

parameters to characterize the smoke yield of materials and to estimate

aerosol properties which affect smoke detector response, loss of

visibility, and radiation from the smokey, upper layer in the compartment of origin.

Dobbins and Mulholland, "The Evolution of Size Distribution During

Particle Formation and Accompanied by Coagulation in Flames", submitted

to J. Combustion Science and Technology.

6 . Smoke Control Design Manual

Over the oast 3 years, CFR, with- support from ASKRAZ and Veteran’s

Administration, has written a design manual for building smoke control

systems which covers the fundamentals of smoke control and the specific

application of zone smoke control and pressurized stairways. This

manual has been published as an ASHRAE special publication and an NBS

handbook and is the first comprehensive design guide for such systems.

Klote, J. H. and Fothergill, J. W. , "Design of Smoke Control Systems for

3uildings", Nat. Bur. Stds. (D.S.) NBS Handbook 141 and ASHRAE publication DSCS , July 1983.

Klote, J. H. , "Smoke Movement through a Suspended Ceiling System", Nat.

Bur. Stds. (U.S.) N3SIR 81-2444, February 1982.

Klote, J. H. , "A Computer Program for Analysis of Smoke Control Systems,

Nat. Bur. Stds. (U.S.) NBSIR 82-2512, June*1983.

Klote, J. H. , "Smoke Control by Stairwell Pressurization, Engineering

Applications of Fire Technology workshop, Society of Fire Protection

Engineers, 3oston, MA, to be published.

Klote, J. H., "Smoke Control for Elevators", Nat. 3ur. Stds. (U.S.)

NBSIR 83-2715, 1983.

7 . Dynamic Air Movement Through a Small Opening

This project involves study of pulsating flows through small openings

such as leakage around closed doors or through construction cracks

around door frames driven by low fluctuating pressure differences.

These fluctuations can be caused by the fire and, most often, by wind

effects on the building. These effects may be important to leakage

through smoke barriers, particularly at some distance from the fire

where buoyancy effects are small.

41
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : The American Institute of Architects Foundation

Grant No. : NB81NADA0237

Grant Title : Fire Safety Evaluation System for Board and Care Homes

Principal Investigator : Earle Kennett

The American Institute of Architects Foundation

1735 New York Avenue, NW

Washington, D.C.

Other Professional Personnel : Daniel Alvord

NBS Scientific Officer: Bernard Levin

Technical Abstract

The Fire Safety Evaluation System for Board and Care Homes is a flexible

fire protection standard for such facilities. It consists of two parts.

One part evaluates the fire safety of the building itself, while the

second part estimates the severity of the evacuation problem presented

by the staff-resident population currently in the facility. The fire

safety of the building, as determined by the first part, must be high

enough to provide sufficient time in the event of a fire to compensate

for the evacuation difficulty of the residents, as estimated by the

second part. Otherwise, the facility "flunks" the system. A simulation

model called the Escape and Rescue Model has aided in the development

and validation of the evaluation system.

The Escape and Rescue Model is a deterministic discrete-event simulation

program written in Simscript II. 5 for the NBS Univac 1180/2 computer.

It is designed to simulate the emergency movement and building occupant

actions involved in escape and/or rescue of people from a board and care home housing a small live-in staff, along with a group of residents

possessing varying degrees of physical or mental disabilities. It may

be used to simulate the emergency evacuation problems of more general

types of buildings, but not as accurately. The reliability of the

results is mainly dependent on the appropriateness of the resident

disabilities and preparation times inputted into the model.

The first step in simulating a facility with the model is to convert

the floor plan into a simpler form. The model represents the building

by means of a network consisting of discrete nodes and straight-line

connectors between them, and people are only permitted to move from

node to node along the connectors. After the network has been prepared,

the staff and the residents must be given initial node locations, the

nature of the residents’ disabilities must be specified as well as their

initial preparation-for-egress times, and a rescue priority must be

42
assigned to each resident initially requiring staff aid. When run with

the aforementioned information, the model prints the input data in a readable format and then computes and prints the time that each resident

reaches safety, each resident's egress route, the total time to clear

the building, and a record of various significant events that occur in

the course of the simulation.

Once a simulation run of a facility has been performed, all input items

are easily adjustable, giving great flexibility to the model. Changing

the input values can provide the user with some idea of the sensitivity

of the evacuation times to alterations in the building and/or its

occupants. The horizontal dimensions of the building may be increased

or reduced by means of a scale factor. An exit route may be "blocked"

with a simple change to the network, forcing an alteration in people

movement. The number of staff and/or residents in the building may be

changed, as well as their initial locations and preparation times. The

movement speed and disability type of each resident are also easilyaltered. Many other factors can be varied.

A survey of Board and Care Homes was recently conducted for NBS to aid

in the calibration of the Fire Safety Evaluation System for Board and

Care Homes. Some of the data in the survey was gathered for use in the

development, calibration, and validation of the Escape and Rescue model.

Daytime fire drills were run in most of the surveyed facilities, and

the initial locations of the residents, their behavior in the drill,

their preparation times, and their movement speeds were observed. A

floor plan of the facility was included. For many facilities which held

a fire drill, the drill information was employed by the Escape and

Rescue Model in an effort to simulate the drill. The simulations almost

invariably agreed well with the actual drills, which is not incredibly

surprising due to the choice of input, but this result still tends to

validate some of the assumptions built into the model. Finally, the

Escape and Rescue Model was used to simulate nighttime emergency

evacuations for some of the facilities which did not conduct fire

drills.

43
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : Brown University

Grant No .: NBS Grant NB80NADA 1024

Grant Title : Effects of Material Properties on Burning and ExtinctionFires on Vertical Fuel Surfaces

Principal Investigator : Professor M. Sibulkin

Division of Engineering

Brown University

Providence, RI 02912

Other Professional Personnel : 5. Malary, Graduate Research Assistant

5. Tewari, Graduate Research Assistant

E. Oren, Graduate Fellowship Student

NBS Scientific Officer : V. Babrauskas

Technical Abstract :

The objective of this program is to determine the effects of

changes in material properties on the burning rates and extinction

limits for solid fuels. A vertical fuel configuration is - used because

it provides the best opportunity to compare experimental results with

the detailed mathematical analyses of diffusion flames which have been

developed. This year work has been completed on a study of the effects

of incomplete combustion on the burning of methyl methacrylate. An

analysis of the effects of external radiation has been made, with re- sults calculated for PMMA. Our present emphasis has shifted from the

study of "vaporizing" fuels (PMMA) to "charring" fuels (cellulose) . An

investigation of the effects of solid-phase fire retardants on the burning of cellulose is in progress.

One of the unsettled questions in the modeling of diffusion flames

is the proper heat of combustion to use in comparing theory with ex- periment. Published calculations are based upon the use of heats of

combustion for complete burning (i.e., bomb calorimeter values). This

year a major task has been to finish a study of the degree of completeness of combustion in a wall fire, and to determine the effect of incomplete combustion on the burning rate. The apparatus used was a vertical, ceramic wick assembly burning liquid methyl methacrylate (MMA)

to simulate the burning of PMMA. Using this apparatus, burning rate

measurements have been made for an ambient oxygen concentration range

of Yg a, = 0.20 to 0.30 . A procedure was developed to eliminate a ten percent uncertainty band in the burning rates obtained in previous

liquid-fed wick measurements which were operated in a "zero dripping"

mode. This was accomplished by measuring the difference between the

fuel supplied and the unbumed fuel collected in a trough below the

44
wick for a range of fuel supply rates. These results were then extrapolated to the zero dripping limit.

During the previous period a gas sampling system had been developed.

This was used to obtain boundary layer profiles of the concentrations

of CO 2 and CO using a two-channel nondispersive infrared analyzer. Results were obtained for the range Yq „

= 0.20 to 0.30 at x = 5.2 cm from the leading edge of the wick, anA at x = 2.8, 5.2, and 7.5 cm at

Yq OT = 0.233. These measurements were primarily made with a watercooled, stainless steel probe (#1) having an outer diameter of 0.120

inches and an inlet diameter of 0.032 inches. The tip of this probe

became blocked with soot in the luminous zone of the boundary layer.

(The width of this high sooting region increased with increasing oxygen

concentration.) Measurements were obtained in the sooting region with

an uncooled quartz probe (#2) with an inlet diameter of 0.050 inches.

Outside the sooting region measurements by both probes were in agreement. The dry gas concentrations for CO 2 and CO are plotted against

distance from the fuel surface y in Fig. 1 for Yq >0O = 0.233 at x = 5.2 cm. These results show that there are large concentrations of

CO between the flame zone and the wall. The maximum value of the CO/CO 2 ratio increases from 0.8 at Y0 =0.20 to 1.1 at Y_ =0.30.

O, 00 0,°°

Because the cold trap in the gas sampling system removes both water

and MMA vapor, the CO 2 and CO concentrations obtained from the IR Analyzer are on a dry gas basis. A data reduction procedure was developed

to convert these concentrations to a total gas basis. The effective

heat of combustion hCje depends upon how much of the fuel goes to CO

rather than CO 2. The total rates of CO and CO 2 production were calculated by integrating across the boundary layer using the measured con- centrations and flow factors obtained from our diffusion flame computer

program. Defining the ratio

R

CO

CO

CO

+ h

CO,

where h is the production rate in moles per second, our results give

values of Rqq which increases from about 0.3 at Yq = 0.20 to 0.4

at Yq a, = 0.30. When these results are used to calculate the heat of

reaction, they give an effective heat of combustion h c e

= 20,000 kJ/kg

which is approximately 20 percent less than the value for complete burning. The variation of Rqq and h c e with Yq is shown in Fig. 2.

These effective heats of combustion will be used as inputs to our diffusion flame computer program. The calculated results will be compared

with our burning rate measurements. This work is being prepared for

publication.

During this period an analytical study was made of the effects of

external radiation on wall fires using our previously developed computer

program for modeling this fire. The fuel considered was PMMA and results

45
were calculated for external flux levels q”

x from 0 to 40 kW/m^ and

for ambient oxygen concentration levels from Yq = 0.23 down to ex- tinction. Previous work had shown that the burning rate is nearly independent of the chemical reaction rate at oxygen concentrations above

extinction. This result was checked and then used to significantly

reduce the effort needed to obtain the burning rate results. The calculations for a fixed value of Yq show an almost linear increase

in burning rate as q^x

increased. However, the slope of the q^x

vs. m£ curve is not equal to the heat of pyrolysis of the fuel, as has been

suggested, due to the great reduction in convective heat flux to the

wall as q^x increases. A considerable effort was devoted to obtaining

extinction limit results as a function of external flux level for finite

chemical reaction rate. The kinetic parameters used were based on published results for PMMA. The variation in the nondimens ional burning rate m* is shown as a function of Yq ^

in Fig. 3 for several

external flux levels qgX . The increase in burning rate with ambient

oxygen concentration is linear. A major finding is that there is only

a small decrease (about 2 percent.) in the value of Yq <_ at extinction

as 'lex is increased from 0 to 40 kW/m^. These results are being prepared for publication.

Experimental work on the burning of pure and fire retarded cellulose cylinders is continuing. A preliminary investigation was made to

evaluate methods for determining the heat of pyrolysis of cellulose.

Our major effort in the next year will be on these problems.

Publication was completed this year of two papers whose findings

were presented in the last conference abstract.

Reports and Papers :

Completed publications

"Free Convection Diffusion Flames with Inert Additives," M. Sibulkin

and C. Y. Wang, Journal of Heat Transfer, 104, 728 (1982).

"Nonsimilar Calculations for Free Convection Diffusion Flames," M.

Sibulkin, A. K. Kulkami, and S. F. Malary, Combustion and Flame, 50 , 59 (1983).

Publications in preparation

"Investigation of Completeness of Combustion in a Wall Fire," M. Sibulkin and S. F. Malary.

"External Radiation Effects on the Burning and Extinction of Wall Fires1,' M. Sibulkin and T. Gale.

Theses

"Calibration of Surface Temperature and Thermal Radiation Instruments,"

S. M. Schneider, Sc.M Thesis, Brown University (1982).

46
"Evaluation of the Heat of Pyrolysis for Cellulose," E. Oren, Sc.M

Thesis, Brown University (1983).

y(mm)

Fig. 1

Fig. 2 Fig. 3.

47
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : California Institute of Technology

Grant No .: NBS Grant NB82NADA3033

Grant Title : Experimental Study of Environment and Heat

Transfer in a Room Fire

Principal Investigator : Professor Edward E. Zukoski 301-46

California Institute of Technology

Pasadena, CA 91125

Other Professional Personnel : Professor Toshi Kubota

Christopher Lim, Ph.D. Candidate

Michael Chobotov, Ph.D. Candidate

California Institute of Technology

Pasadena, CA 91125

NBS Scientific Officer : Dr. James Quint iere

Technical Abstract

Producing rational models of smoke movement in complex structures

requires an understanding of a number of turbulent flow processes. We

have been studying several of these processes and have also developed

a simple computer model based on these results. We have been interested

primarily in the plumes produced by a fire or by a flow of hot gas

through openings, and have been investigating the entrainment rates of

the plumes and the heat transfer rates produced by the impingement of

the plumes on the ceiling of a room. A simple computer code has been

developed which describes smoke movement in pre-flashover , two room configurations. This modeling effort has aided us in our selection of

experimental problems. Some of our current work is described in the

following paragraphs.

Experimental Progress

Heat Transfer . During the past year we have completed the documentation of the experimental work we have carried out on the heat

transferred to the walls of a room as the result of a fire within the

room. See Reference 1

The primary data refer to steady state convective heat transfer to

the ceiling but, in order to develop a rational description of this

process , we were also forced to develop a model of the flow produced by

the fire plume within the room and to compute radiant heat transfer

48
between the surfaces forming the room. The flow field model includes a crude description of the plume-interface interaction region and a model

of the hot ceiling jet formed by the plume impingement on the ceiling.

This flow field model is being modified to allow us to include in our Room Fire Model a calculation of heat loss to the walls, ceiling

and floor. We are also in the process of including a calculation of the

heat transfer to objects placed within the room such as a sprinkler head

placed some distance below the ceiling.

The radiant heat transfer treatment is limited because, although

radiant heat transfer between solid surfaces is taken into account, gas

phase radiant transfer processes are not included. Thus, heat transfer

between side walls, the ceiling and floor, and other solid objects within the room can be included in these calculations but heat transfer

from a sooty gas to the wall cannot. The surfaces bounding the room

are divided into a manageable number of flat elements and a single

temperature is used to describe the surface condition of each element.

View factors are calculated by a computer code given the room geometry

and the temperature of each element is calculated from a transient heat

transfer program. The calculation of the heat transfer into the wall

is treated with a one-dimensional model and a single temperature

distribution within the wall is required to describe each surface

element.

We have had some success with early versions of this work in

describing heat transfer in room fire tests carried out at, the

Lawrence Livermore Laboratory.

Combustion in a Fuel-Rich Ceiling Layer . We are also in the process of completing our work on the entrainment of fire plumes. The

material, reported in Reference 2, has been incorporated in the Room

Fire Model.

Current work includes an extension of our study of combustion in

the fuel-rich ceiling layer. This work is a study of combustion which

occurs in a diffusion flame which has its base in unvitiated air, but

which extends for an appreciable fraction of its height into a ceiling

layer composed of the products of combustion formed by the flame itself.

We are examining the products of combustion formed by this system as

a function of the height of the flame in the two regions, the temperature of the ceiling layer gas (which is fixed by heat loss from the

layer) and the fuel flow rate or heat release rate of the diffusion

flame.

Measurements are being made with a hood which is a cube with a side of 1.22 meters, heat release rates of 10 to 100 kW, and flame

heights in unvitiated air as small as 20 cm. During the past year

we have carried out measurements to develop a more accurate set of

data than those previously reported. These data were substantially

unaltered from those previously discussed. Thus, when the ceiling

layer temperatures are in the range 750 to 900 K. the gas composi49
tion within the ceiling layer (i.e., the hood) has a composition which

is, within our rather large experimental scatter, close to the

corresponding equilibrium value. These results were obtained with

methane as the fuel and for fuel-air ratios of the gases entering the

hood which lie in the range of equivalence ratios between 0.1 and 2.20.

In addition, we have ignored the contribution of the soot to the mass balances

The products become combustible for values of the equivalence

ratios which are greater than about 2.0 and, for this condition,

vigorous burning of the products was noted in a door-jet flow configuration. Little combustion within the ceiling layer itself has been

observed although the diffusion flame does act as an ignition source

for the flame which is observed to lie at the horizontal interface

between ceiling layer gas and unvitiated air.

The average height of the diffusion flames burning in the vitiated

air within the hood were determined by observing the top of the flames

through two 30 cm square pyrex windows located in the side of the hood.

Average values determined by eye were the equal to the values determined

for identical diffusion flames burning in unvitiated air to within our observational reproducibility of 5 to 10%. This surprising result was

found to hold even for the very fuel-rich cases for which the ceiling

layer gas had an oxygen mass fraction of less than 1%.

These studies also are giving us a better picture of the air en- trainment process when the flame extends deeply into the ceiling layer.

Flame Dynamics . We have also started this year to study in a more

detailed manner the large structures which are formed in the buoyant

diffusion flames we have been using as a source for the buoyant plume

entrainment work. These flames are characterized by a regular pulsation

in the diameter of the flame near the burner which appears to be associated with the formation of vortical structures. See Reference 2.

We believe that these structures fix to a large degree the entrainment processes in the fire itself and perhaps also in the plume above

the visible flame. This year, we initiated a study of these structures

which have involved the use of simultaneous direct and shadowgraph

photographs of the flame and near field of the plume. High speed

motion pictures and short duration spark techniques are being used.

Door Way Entrainment . We are investigating the entrainment from

the hot ceiling layer of a room into the floor layer by the action of

the flow in and out of a doorway which is itself fixed by a fire within

the room. The experiments are being carried out in a half scale room

model, a room 1.22m high by 1.22m wide by 2.4m long, and with doors

which are in the center of the 1.22 by 1.22m end. Entrainment rates

are inferred from a mass balance made on a tracer which is introduced

into the ceiling layer gas at a known rate.

We have had considerable success in correlating the results of

50
this work with a parameter similar to a Richardson number. This is a continuing project and the final analysis has not been completed.

Reports and Papers

1. Sargent, William Stapf, "Natural Convection Flows and Associated

Heat Transfer Processes in Room Fires," Ph.D. Thesis, California

Institute of Technology, 1983.

2. Cetegen, B. M. , Zukoski, E. E. and Kubota, T. , "Entrainment and

Flame Geometry of Fire Plumes," Report for Center for Fire

Research, NBS, California Institute of Technology, August, 1982.

51
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

I nstitution : Case Western Reserve University

Contract Number : NB82NADA3028

Contract Title : Experimental and Analytical Study of Fire Sprinkler

Scaling Laws

Principal Investigator : Joseph M. Prahl, Ph.D., P.E.

Associate Professor of Engineering

Dept, of Mechanical and Aerospace Engineering

Case Western Reserve University

Cleveland, Ohio 44106

NBS Scientific Officer : David D . Evans

Technical Abstract

The objective of this project is to develop an experimental base

that will delineate the relevant scaling parameters that govern the

ultimate performance of a wide class of fire sprinklers. The sheet

trajectory, sheet breakup, and subsequent droplet size distribution and

droplet trajectories will be related dimensionless ly to the mechanical

and thermal properties of the liquid and gaseous fluids, the geometry,

and the initial dynamics of the liquid and gaseous streams.

An apparatus has been designed and built to study the axisymmetric

jet impingement on a flat disk which can be vibrated axially at a given

frequency and chosen amplitudes. Several nozzle and disk sizes can be

interchanged as well as varying the initial fluid velocity and distance

between the nozzle and disk. The fluid itself can ultimately be varied

as the flow system is recirculating. At present, the system is being

preliminarily tested with water. A 22 and 1/2 degree sector of the

axisymmetric discharge pattern will be studied intensively. The effects

of surface characteristics of the disk as well as frequency and amplitude of vibration will be considered in detail first to specify the

effect these parameters have on the sheet breakup location and the droplet size distribution that results. The droplet trajectories will be

determined by catching the spray in a series of rain gutters spanning the

floor of the sector in question.

If consistent results are obtained with water, other fluids with

different surface tension properties will be tested in the rig to build

confidence in the dimensionless parameters that appear to govern the

behavior of the resulting sprays.

52
The tests planned for summer, 1983, are preliminary in nature and

will be used to guide the investigators as to the appropriate level of

instrumentation required to completely characterize the phenomenon.

Reports and Papers

No reports and/or papers have resulted from this work as yet.

53
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : Case Western Reserve University

Grant No: NB83NADA4002

Grant Title : Flame Spread and Spread Limits

Principal Investigator : Professor James S. T'ien

Department of Mechanical and Aerospace

Engineering

Case Western Reserve University

Cleveland, Ohio 44106

Other Professional Personnel : Charlie Chen (Graduate Student)

NBS Scientific Officer: Dr. James G. Quintiere

Technical Abstract

The overall objective of this research program is to develop basic

understanding of flame spread with special emphasis on flame spread

limits. The work involves experimental and theoretical modeling efforts

for both downward (opposed flow) and upward (concurrent flow) flame

spreads.

During this report period, the fire plume region along a vertical

wass was ivnestigated theoretically. The fire plume plays an important

role in fire growth and upward flame spreading processes because it

determines the heat flux level to the unburnt fuel surface. Furthermore,

the quenching of chemical reactions near the tip of the combustion plume

results in the escape of the unbumt fuel or combustion intermediates

from the flame which produces them. These escaped pyrolyzates can either constitute as air pollutants or serve as fuels to be burnt later

elsewhere (such as in the smoke layer in a room) . Thus the study of

the fire plume can have a number of practical implications to fire

research.

Previous investigations on wall fire plume have employed the assum- ption of infinite-fast chemical kinetics [1, 2]. The present work

emphasizes the effects of finite-rate gas-phase chemical reactions. The

model assumes a naturally-convective laminar boundary layer along a vertical surface. The chemical reactions include two semi-global steps:

in the first, fuel is oxidized to form carbon monoxide and water vapor

and, in the second, carbon monoxide is oxidized to form carbon dioxide.

Four important nondimensional kinetic parameters are identified: two

dimensionless frequency factors (Damkohler numbers) and two dimensionless activation energy. A parametric study is used to investigate the

effect of these parameters. The computed results indicate that by

slowing down the relative kinetic rates in the gas-phase reactions, the

54
total heat transfer rate and the preheating distance are decreased

(Fig. 1). Furthermore, slowing down the kinetics also increases the

amount of unreacted combustibles which escape from the flame (Fig. 2).

The result of this plume model will be used to study the upward

flame growth or spread rates and the spread limiting phenomena.

References

1. Ahmad T. and Faeth, G.M. , "An Investigation of the Laminar Overfire

Region Along Upright Surfaces", vol. 100, 1978, J. of Heat Transfer,

pp. 112-119.

2. Pagni, P.J. and Shih, T.M. , "Excess Pyrolzate", 16th Sym. (Int.) on Combustion, The Combustion Institute, Pittsburgh, 1977. pp . 1329-

1343.

Reports and Papers

Borgeson, R.A. , "Flame Spread and Spread Limits", NBS-GCR-82-396

,

July 1982.

Borgeson, R.A. and T'ien, J.S., "Modelling the Fuel Temperature Effect

on Flame Spread Limits in Opposed Flows", Combustion Science and Technology, 32, 125 (1983)

.

Chen, C.H. and T'ien, J.S., "Fire Plume along Vertical Surfaces: Effect

of Finite-Rate Chemical Reactions", to be presented in the -1983 ASME/

AIChE National Heat Transfer Conference, Seattle, Washington, July 24-

28, 1983.

55
0.6

Fig. 1 Nondimensional surface heat transfer rates vs. nondimens i-onal

distance the effect of non-dimensional fuel frequency factor

variation. The plume starts at £=1, pyrolysis region is from

£=0 to C*l.

i

Fig. 2 Fuel mass flux ratio (fuel mass flux divided by fuel mass flux at

the plume starting plane) vs. %

:

the effect of nondimensional fuel

frequency factor variation. The flatten curves indicate the chemical-frozen region and give the ratios of unbumt fuel escaped

from the flame.

56
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : Cl emson University

Grant No : NBS Grant NB80NADA1042

Grant Title : Ternary Reactions Among Polymer Substrate-Organohal ogenAntimony Oxides in the Condensed Phase Under Pyrolytic,

Oxidative and Flaming Conditions.

Principal Investigator : Dr. M. J. Drews

School of Textiles

Cl emson University

Cl emson, South Carolina 29631

Other Professional Personnel : Dr. C. W. Jarvis, Co-principal

Investigator

Dr. J. Reece, Post-doctoral Research

Associate

Mr. T. Gil strap, Graduate Assistant

Ms. B. Lee, Graduate Assistant

NBS Scientific Officer: Dr. G. Mallard

Technical Abstract :

The objective of this study is to determine the contributions of

the solid phase interactions, occuring in antimony oxide/organohal ogen/

thermoplastic polymer substrate compositions, to the overall system

chemistry during combustion. Of particular interest is the role of

the polymer substrate in the generation of volatile antimony and halogen

containing species. Small scale degradation data are to be integrated

with the results from laboratory scale flaming combustion experiments

conducted at the Center for Fire Research of the National Bureau of

Standards. The flaming combustion and degradation data are to be used

in an attempt to develop a comprehensive model for the chemistry which

occurs in the condensed phase, under both flaming and non-flaming

degradation conditions. This model is to be used in the identification

of the controlling parameters for optimizing the efficiency of organohalogen/antimony oxide flame retardant combinations in specific

polymer substrates.

The research plan has been divided into two concurrent pathways.

The first pathway consists of small scale degradation studies to be

conducted throughout the lifetime of the project. These degradation

studies are designed to characterize the thermally initiated ternary

reactions, which could affect halogen and antimony release in the

condensed phase, occuring in mixtures of polymer substrate/organobromine additive/antimony oxide. These data will then be correlated

with the previous results obtained in studies of the reactions

57
involving the individual components and binary mixtures. From these

two data sets, the changes in the rates of antimony and/or bromine

volatilization, the temperature profiles for antimony and bromine

release, and the relative concentrations for the various volatilized

bromine and antimony species will be used to define the role of the

polymer substrate structure in the halogen and antimony loss from the

solid phase. Three polymer substrates are being studied: polymethylmethacrylate (PMMA), polypropylene (PP) and polyethylene terephthal ate

(PET). Three organo bromine compounds are being used as model organohalogen additives: hexabromocyclododecane (HBCD), tetrabromobi sphenol

A (TBBPA) and decabromodi phenyl oxide (DBDPO). The study of mixtures

of each of the above with antimony tri oxide or antimony pentoxide

consists of a sequence of experiments including but not limited to,

dynamic (at three different heating rates) and isothermal (at two

different temperatures) decomposition studies in three different

atmospheres; pyrolytic (nitrogen), catalytic (1% oxygen) and ambient

(21% oxygen).

The second pathway in the research plan includes laboratory scale

flaming combustion experiments conducted at the Center for Fire

Research at the National Bureau of Standards during the project. In

these experiments, the effects on combustion parameters such as sample

thickness and geometry, as well as polymer substrate additive

concentrations are to be studied. The apparatus to be used for these

flaming combustion experiments is the cone calorimeter developed by

Parker, Babrauskas, and Swanson. Several combustion parameters are measured for each sample including; time to ignition, rate of heat

release, mass consumption rate, and the gravimetric smoke yield.

While the combustion data gathered to date represent a limited

sampling, they clearly indicate that the solid state chemistry can not

be completely isolated from the gas phase reactions. In particular

these data reflect the effects of the relative additive stabilities on the overall ability of a halogen/antimony system to disturb the

combustion envelope as represented by oxygen depletion and carbon

monoxide/dioxide formation. That these effects occur, even in the

downward burning candlelike geometry using thermally thick samples is

surprising but in accord with the basic hypothesis of this work.

Perhaps even more surprising is ;he observation that the closer the

match between the substrate and organohal ogen stabilities, the less

the base burning behavior, in terms of these gases, is disturbed. One

would have initially expected a maximum deviation for this case. In addition, these data show that significant changes in flame height,

smoke generation and incomplete combustion as measured by CO formation

may occur while the mass consumption rate remains essentially

unchanged.

While these results obtained on the cone calorimeter so far are extremely interesting, because such a limited amount of data is

available, it is difficult to draw any concrete conclusions regarding

some of the observations that have been made. It appears more

58
promising than ever, however, that when combined with the thermal

analysis results these data will lead to a significant increase in the

understanding of the effects of antimony/halogen systems on the

combustion performance of polymer substrates.

From the initial experiments until the present time difficulties

have been encountered in obtaining complete mass balances of the

reactive components in the ternary mixtures. As a result, during the

past project year a decision has been made to begin larger scale

pyrolysis in a tube furnace apparatus. In order to maintain the

experimental consistency which has been designed into this work, it

therefore became necessary to repeat some of our earlier single

component and binary mixture studies in the tube furnace. These data

were consistent with the thermal analysis experiments in that, only in

the ternary mixture and melt (melt blended mixture) has any evidence

for significant chemical reaction and antimony volatilization been

observed.

To date, however, even in the tube furnace experiments, mass balances of the additives and antimony have been obtained in only a limited number of cases. Consequently, the research plan for the

current project year has undergone substantial modification with respect

to the pyrolysis work. New polymer substrates and organohalogen

additives will be screened in an attempt to discover a system more

amenable to analysis by the techniques which have been developed during

the course of this work.

The results of this systematic investigation are intended to make

available new basic information in several important areas: formation

of volatile antimony species from reactions of antimony oxides with

organo halogens that cannot by themselves eliminate hydrogen halide;

the effect of the polymer substrate on the reactions which produce

volatile antimony halides and oxy halides; and the first systematic

study on the controlled combustion of thermoplastic materials containing organohalogen/antimony oxide flame retardants. The systems

description which this research program seeks to develop should make it

possible to model more accurately combustion performance of these

materials in fire situations and lead to a greater understanding of the

thermal characteristics necessary for the more efficient flame

retardation of thermoplastic materials.

Reports and Papers :

Drews, M. J., Jarvis, C. W., Leibner, E. A., "Organobromine/Antimony

Oxide/Polymer Substrate Interactions in the Solid Phase. Part I. Binary Interactions," Organic Coatings and Plastics Preprints, 43_, 181

(1980).

Hansel, J. D., "Solid Phase Interactions Among Antimony Oxides,

Decabromodi phenyl Oxide and Polypropyl ene Under Pyrolytic Conditions,"

Masters Thesis in preparation.

59
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution: Colorado School of Mines

Grant No. : NBS1NADA2020

Grant Title : Characterization of Aerosols from Fires

Principal Investigator: Professor Kent J. Voorhees

Department of Chemistry and Geochemistry

Colorado School of Mines

Golden, CO 80401

Other Professional Personnel : Dr. R. Tsao, Post-Doctoral Associate

Mr. S.A. Durfee, Ph.D. Candidate

NBS Scientific Officer: Ms. Maya Paabo

Technical Abstract

The objective of this research program is to determine, using

pyrolysis/mass spectrometry (Py-MS ) /pattern recognition procedures,

the composition of the polymeric materials in combustion aerosols

and relate this information to the fuels involved in the combustion

process. Single polymer and wood samples have been individually

decomposed in both flaming and nonflaming modes and the aerosols

collected. The pyrolysis /mass spectra have been recorded as reference

spectra for these materials. Polymer and wood mixtures have also been

decomposed and the aerosols investigated by Py-MS. Various pattern

recognition procedures with and without reference spectra have been

used to determine the number of components as well as identification

of the components of the mixture. A similar procedure has also been

applied to single polymer and wood samples and combination mixtures

where gasoline was present. The results in these areas will be

individually discussed.

1 . Aerosols from Flaming and Nonflaming Degradation

The aerosols collected from 11 polymer samples, 3 wood samples

and gasoline all produced pyrolysis/mass spectra which were unique for

the original sample. Differences were noted between the aerosols

produced from flaming and nonflaming conditions. All of the

individual samples were either extracted or vacuum treated to remove

the volatile (low molecular) portion. In many cases, particularly in

the nonflaming aerosols, the pyrolysis/mass spectra were quite similar

to the pyrolysis /mass spectra of the original polymers.

2 . Pattern Recognition

Four pattern recognition procedures have been applied to mixture

aerosol Py-MS data. Multivariate statistics have been used for

60
differentiating between samples; abstract factor analysis for

determining the number of components; and least squares fitting and

targeted factor analysis, both using reference spectra, for

identifying and quantifying the components in the mixtures. The

ARTHUR package (1) for multivariate statistics has been extensively

proven reliable in our laboratory. The other three approaches have

been carefully tested using synthesized data from the individual

reference spectra. For the test data, abstract factor analysis (1)

predicted the correct number of components in a set of spectra almost

routinely. Both the least squares approach (2) and the targeted

factor analysis (3) have correctly identified species in the mixtures

with a 90 percent record. Quantitation for the synthesized data was acceptable and follows the values originally reported by Fausett and

Weber ( 2)

.

3 . Factor Analysis of Nonflaming Mixture Analysis

Twenty mixtures (2 unique sets) each containing up to 4

components were formulated at various compositions from the 10

original polymers. Analysis of the pyrolysis data from these 20

mixtures by multivariate statistics showed that each mixture produced

a unique Py-MS pattern. The spectrum for each mixture was first

visually analyzed using the mass spectral peaks characteristic of the

components of the mixture. Next, principal components factor analysis

was done. In order to extract the chemical information, a series of

graphical rotations were performed on the first six factors. Figure 1

represents the spectrum generated by rotation of factor 1 by 135° with

respect to factor 2. The upper part of this spectrum corresponds to

polyurethane GM-29 . The spectrum of the original GM-29 is. shown in

Figure 2. Similar data was extracted for most species contained in

the mixtures. In general, this approach was used to predict the

components in the mixtures with 88 percent correctness.

A least squares approach was also applied to the pyrolysis data

for quantitation (3). The program used reference spectra for a best

fit to the mixture mass spectrum. The results of the least squares

analysis showed that some materials such as PVC in relation to the

amount in the mixture produces large quantities of polymeric

aerosol. Others are affected by accompanying materials in the mixture

and show no predictable trend.

In addition, a series of aerosols collected from flaming

combustion has been analyzed using a similar approach. The data

generated from aerosols from the Potts furnace were extremely variable

and gave factor analysis results which were difficult to interpret.

Aerosols from the NBS furniture calorimeter were pyrolyzed to give

data which were more like the results generated from the nonflaming

experiments. In general, the data from the Potts furnace in the

flaming mode showed a more complete degradation of the material.

4 . Samples Containing Gasoline

A new approach has been developed for analyzing aerosol samples

suspected of containing gasoline residues. In the past only the

polymeric material has been used in the analysis. The new procedure

now uses the volatile compounds. The filters after collection are

61
placed in glass jars with a Curie point wire containing activated

carbon glued on the end. Experiments have been completed on several

mixture sets containing up to three components plus gasoline. Figure

3 shows the volatile spectrum of gasoline. Important in this spectrum

are the peaks between m/ z 130-160. Figure 4 shows the factor gasoline

spectrum from one of the mixture sets spiked with gasoline. In all

data examined to date, a factor gasoline spectrum has been obtained.

Although some peaks may not appear, the gasoline spectrum can easily

be recognized.

References

1 . A. Harper, D.L. Duewer, B.R. Kowalski and J.L. Fasching, in

"Chemoraetrics : Theory and Applications,” ACS Symposium Series No.

52, B.R. Kowalski, ed. , American Chemical Society (1977) pp. 14-

52.

D. W. irausett and J.H. Weber, Anal. Chem. , 50, 722 (1978).

3. E.R. Maunowski and D.G. Howery, "Factor Analysis in Chemistry,”

John Wiley & Sons, New York, and others, 1980.

Reports and Papers

"Characterization of Aerosols from Fires," presented at Fifth

International Symposium on Analytical Pyrolysis, Vail, Colorado

(1982).

"Characterization of Aerosols from Nonflaming Combustion," presented

at American Society of Mass Spectrometry, Boston, Massachusetts

(1983).

"Characterization of Aerosols from Nonflaming Combustion," submitted

to Analytical Chemistry.

30 50 70 90 110 130 150 170 190 210 230

Figure 1. Factor spectrum of polyurethane.

62
001

Figure 2. Py-MS spectrum of polyurethane

Figure 3. Spectrum of gasoline vapors.

Figure 4. Factor spectrum of gasoline.

63
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : Factory Mutual Research Corporation

Contract Number : NB 82-NADA-3041

Contract Title : Computer Modeling of Aircraft Cabin Fire Phenomena

Principal Investigator : Dr. M. A. Delichatsios

Research Specialist

Factory Mutual Research Corporation

Norwood, MA 02062

NBS Scientific Officer : Kenneth Steckler

Technical Abstract

The objective of this program is to develop simple integral models

for wall and ceiling fires, including radiation effects which can be

incoporated in the form of computer subroutines into existing codes for

the prediction of fire growth in aircraft cabin fires.

The major accomplishments over the current period are:

1. The integral model for turbulent burning on a vertical wall,

which was developed in the previous year, has been extended to include

flame and external radiation interactions^ . The predictions of the

model agree within ten per cent with experimental measurements of the

pyrolysis rate on vertical PMMA wall fires

2. It has been shown, based on simple dimensional arguments, that

for all buoyant diffusion flames (including wall fires) the flame height

depends only on the heat release rate and it is independent of the

stoichiommetry^ . In addition, for laminar or turbulent, buoyant wall

fires it has been shown by comparison with experiments (turbulent) or exact solutions (laminar) that the flame height is independent of the

extent of the pyrolysis region if the flame extent is much larger (by a factor of 3) than that of the pyrolysis region. For this case the wall

flame height, h^ is given by:

laminar flames:

h

f 0.16 444 2

\ P C T v g

\ o p o o turbulent flames:

1/3

( 1 )

'2 \ 1/3

h

f

4,65

I 222

C

p T

o

P S

( 2 )

64
In these equations, 0 is the heat release rate per unit width and the

other parameters are properties of the ambient air; g is the

gravitational constant.

3. Based on an analytical model of pyrolysis of charring materials

(developed under another contract), critical conditions have been

formulated for self-sustained burning and flame propogation on vertical

charring walls ^ . The maximum depth of char before pyrolysis ceases is

determined. In addition, critical conditions of flame propagation and

extinction downstream of the pyrolysing segment are developed. Such

parameters can be used to characterize the flammability of charring

materials.

Reports and Papers

1. Delichatsios , M.A. and Mathews, M.K. , "Turbulent Wall Burning with

External and Flame Radiation," presented at the Eastern Section

Meeting of the Combustion Insititute, Atlantic City, New Jersey.

2. Delichatsios, M.A., "Flame Heights in Buoyant Diffusion Flames and a New Material Flammability Number," FMRC Memorandum,

March 30, 1983.

3. Delichatsios, M.A. , "Critical Conditions for Sustained Burning and

Flame Propagation on Vertical Charring Walls," for presentation at

the ASME Meeting, Boston, MA, November 1983.

65
Institution; Factory Mutual Research Corporation

Grant No. ; NB79NADA0014 , Amendment/Modification No. 3

Grant Title : Determination of Fuel Parameters for Fire Modeling

Principal Investigator : Archibald Tewarson, Ph.D.

Manager, Flammability Section

Factory Mutual Research Corporation

1151 Boston-Providence Turnpike

Norwood, MA 02062

Other Professional Personnel: J. Steciak and S.D. Ogden

NBS Scientific Officer: William J. Parker

Technical Abstract

The objective of the study was to examine the influence of air

contaminants on the fuel parameters. Polymethylmethacrylate (PMMA)

,

cellulose and polyvinylchloride (PVC) were used as fuels.

The replacement of nitrogen by CO2 in concentrations of up to 7 %

did not significantly change the fuel parameters as long as the volume

concentration of oxygen remained the same. The effect of CO

2 as a con- taminate was important when it resulted in a reduction in O2

concentration.

For enclosed spaces, a ventilation parameter, $, was defined as the

ratio of the total mass flow rate of oxygen introduced into the enclosed

space to the mass consumption rate of oxygen for stoichiometric combustion. The flame height, combustion efficiency, product generation efficiencies and oxygen consumption in the combustion process were found

to be proportional to <f>“ n . For flame height, Pagni's relationships

were used [1-4], The flame height was found to vary with (t) -1 **3 and to

depend on the fuel property (L/k-^) -11

; in agreement with Annamalai

and Sibulkin [5]

,

L is the actual heat of gasification and kQ2 is stoichiometric mass oxygen- to- fuel ratio, although the value of n under our experimental conditions was different from the theoretical n value of

Annamalai and Sibulkin for different geometry.

The flame height was found to vary with the 1.5 power of the net

heat flux absorbed by the fuel. Air velocity was found to have a significant effect on the flame height.

The combustion efficiency was found to decrease with decrease in cp

.

The fraction of total mass flow rate of oxygen consumed in the combustion process was found to vary with

The ratio of the generation efficiency of the product of

incomplete combustion (CO, hydrocarbons and "smoke") to the generation

~>t CO2 was found to follow the relationship:

f

J /fC02 ~ <r

'1 (1)

66
where f is the generation efficiency, and j is either CO or hydrocarbons

or "smoke."

The experimental n values are listed in Table 1 for PMMA and PVC.

Table 1

Experimental n Values in Equation (1)

n

1 PMMA PVC

f

C0

/f C0

2

>4 -1

^hydrocarbons

f

C0

2

.4 .2

^ smoke^CO 0 >3 -

f others*

/f

C0

2 ,2

others: carbon compounds other than C0

?

, CO,

hydrocarbons and "smoke."

The data in Table 1 indicate that the generation of CO and hydrocarbons

is more sensitive to for PMMA than it is for PVC. Also, for PMMA the

generation of "smoke" or carbon compounds other than CO2, CO, hydrocarbons and "smoke" is not as sensitive to <p as the generation of CO

and hydrocarbons.

It should be pointed out that, although the data are useful for en- closure fire models, they are very limited and are only experimental.

For general applicability, data for other fuels including larger-scale

fire test data and calculations are needed.

Reports and Papers

Tewarson, A. and Steciak, J. , "Fire Ventilation," National Bureau of

Standards, Washington, D.C., Technical Report NBS-GCR-83-423

,

February 1983, National Technical Information Service, Springfield,

Virginia, Order No. PB83-183293. (Paper based on the report is accepted

for publication in Combustion and Flame)

.

References

1. Pagni, P.J. and Shih, T.M. , 16th Symposium (International) on Combustion , The Combustion Institute, Pittsburgh, PA, 1976, p. 1329.

2. Kinoshita, C.M. and Pagni, P.J., Transactions of ASME, 102, 104,

1980.

3.

Pagni, P.J., Fire Safety Journal , 3_, 273, 1980/81.

67
4. Cagle, C.L. and Pagni, P.J., Radiative Effects on Diffusion Flame

Heights, Lawrence Berkeley Laboratory, Energy Environment Division,

University of California, Berkeley, CA, Technical Report LBL-14008

,

January 1982.

5. Annamalai, K. and Sibulkin, M. , Combustion Science and Technology

19, 185, 1979.

" ‘

68
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS.

FY 83

Institution : Factory Mutual Research Corporation (Joint program with

Harvard; see Harvard's summary)

Grant No. : NB82NADA3Q30 - NBS Scientific Officer : J. Quint ie re

Title : Prediction of Fire Dynamics.

Principal Investigator : R. Friedman (FMRC) ; H. W. Emmons (Harvard)

Other Professional Personnel: See individual tasks

Summary Comments :

The program consists of five tasks. The first task, by Harvard,

is the refinement of a computer model of a growing fire in an enclosure; the remaining tasks, by FMRC, are to develop critical scientific

knowledge elements needed to quantify a growing, fire. The bulk of the

work is concerned with a more accurate characterization of a fire

plume with regard to entrainment rate, distribution of incompletely

burned chemical species, and radiation emitted- One task is particularly concerned with charring combustibles y which are of great practical importance.

Task 1 : The Prediction of Fire in an Enclosure (See Harvard"s abstract)

Task 2 : Vitiation and Entrainment in Pool Fires

Task Leader : Michael A. Delichatsios

Technical Abstract

The objectives are: 1) to measure precisely the entrainment

rates in turbulent flames; 2) to measure the influence of vitiation in

the air or fuel side on turbulent flames. A reliable procedure has

been developed for measuring entrainment in turbulent jet flames. The

entrainment rate in turbulent fires is required for implementation of

computer codes concerning fire growth in enclosures; the entrainment

rate affects fire growth rate and development of the smoke layer. In

existing codes, entrainment in turbulent fires is calculated by using

the Taylor hypothesis: entrainment velocity is proportional to maximum velocity at any height in the fire plume. Existing data are not

sufficient to verify the Taylor hypothesis in turbulent diffusion

flames. Recent data provided entrainment values varying by a factor of

three for comparable diffusion flames.

In our setup, a buoyant flame jet burned under quiescent

69
conditions inside the enclosure constructed for this project. The

supply air is provided by a blower at the bottom of the enclosure

through four 15 cm ducts, a stone-bed and a screen. The supply air flow

rate can be varied by using a variable-voltage motor to drive the blower. The air. flow rate is measured at the inlet of the tank by concen- tration measurements of a diluent injected upstream of the blower. At

the upper part of the tank an orifice plate has been installed with a variable opening size: 15, 20, 25, 30.5, 40.6 and 56 cm. The base of

the turbulent jet flame can be moved relative to the orifice plate. We

have taken extreme measures to eliminate scatter in the data due to

(thermal) gravity effects; these measures include the cooling of the

pressure tubes, the orifice plate, and the walls of the tank.

The principle of the measuring technique is the following: the mass entrainment rate is that flow rate of the supply air for which the

pressure differential across the orifice plate is zero. This technique

will measure the true entrainment rate only if the orifice size is

somewhat larger than the plume dimensions at the orifice level. In

this case, large-scale eddies associated with the plume will flow

freely through the opening.

Figure 1 shows measurements of the entrainment rate for two orifice openings as a function of the distance from the source of the

buoyant jet plume. We think that the reason the entrainment rates differ for the two orifices is that there are still some residual disturbances in the ambient flow. Presently, two modifications are being

made in order to eliminate any such effects:

a) two additional screens at the entrance of the supply air are being installed in order to further reduce large-scale vorticity in the ambient air;

b) The water-cooled walls will be maintained at the identical

temperature as the supplied air, in order to eliminate any

buoyant drafts coming from the walls of the tank.

( 2 ) In conjunction with previous measurements of the heat release

rate as a function of distance from the nozzle, the entrainment measurements will be used also to determine the effectiveness of mixing and

combustion in a turbulent jet flame. Once we have completed these en- trainment measurements we will examine the effects of ambient/fuel

vitiation on the radiation from the same buoyant turbulent fuel jets.

Reports and Papers

1. Santo, G. and Delichatsios , M.A. , "Effects of Vitiated Air on Radiation and Completeness of Combustion in Propane Pool Fires,"

submitted for publication in Fire Safety Journal.

2. Tamanini, F. , "Direct Measurements of the Longitudinal Variation

of Burning Rates and Product Yield in. Diffusion Flames," accepted

for publication in Combustion and Flame (summer 1983).

70
AIR ENTRAINMENT ( G/S )

Task 3 : Chemical Scaling of Pool Fires

Task Leader : Lawrence Orloff

Technical Abstract :

The objective is to model the burning of large pool fires by using

chemical concentration profiles of major species (0^, CO^, CO, H^O , H^,

THC) obtained from corresponding medium-scale fires. By recourse to

Froude modeling, these concentration profiles are expected to be scaled

in large pool fires.

Accurate gas sampling and species concentration techniques were developed in 1982. A special water-cooled sampling probe was tested in

order to ensure constant mass flow sampling in sooty fires. The probe

features a narrow passageway in. order to very rapidly cool the gases to

achieve constant mass flow sampling of the fluctuating composition.

Heavily soot-laden sample gases present unusual challenges of flow re- striction and filtration. The experimental methods developed here with

propylene fires should also apply to many real-world combustibles.

Soot concentration profiles have been measured in Task 4. Such

soot data is important to the current chemical scaling and material

flammability studies because it is the thermal radiation from soot that

controls burning. Markstein has observed a knee in curves of soot con- centrations at a fixed location vs. pyrolysis rate. There appears to

71
be a critical fuel blowing rate that engenders reduced oxygen concentration, reduced burning and lower soot temperatures. Concentration

data for gaseous species in experiments replicating Markstein’s pool

fires are being measured in this study in order to describe the conditions enhancing or retarding soot formation in turbulent fires. This

aspect of the study should provide insights to effects of fuel blowing

on flammability.

The molecular species directly measured are 0^ , CO^, CO, ELO and

total hydrocarbons; is inferred from the sample thermal conductivity

and from gas chromatographic analysis; soot concentrations were measured by a fiber-optic probe measurement in Task 4; an average flame

temperature is inferred from a thermocouple attached to a 6 mm copper

sphere. Measurements of species concentration profiles have been obtained for 38 cm diameter propylene, propane, and methane pool fires

with and without a lip. There is some indication that species concen- trations correlate with oxygen depletion, and that C0o concentration

correlates well with measurements of soot concentration carried out in

Task 4. Further work to establish, the validity of the concentration

data and to test the chemical modeling concept with measurements in

0.8 m diameter fires is planned.

Task 4 : Radiation from Flames

Task Leader : George H. Markstein

Technical Abstract

In many fires, energy transfer from the flame to the fuel and to

the surroundings occurs predominantly by thermal radiation. The main

objective of the present task, is the development of techniques for

measuring the pertinent' radiative properties of fires, and to provide a quantitative basis for predicting the resulting radiative energy transfer. The rate of fire growth and the spread of fire to new fuel elements depends critically on this energy transfer, and its quantitative

assessment is thus essential for estimating fire losses and threat to

life safety.

Recent work under this task has concentrated on measurements with a fiber-optic absorption probe on gaseous-fuel pool fires. Deficiencies

of an earlier design of the probe caused by thermal expansion effects on optical alignment were eliminated by extensive redesign of the device.

The scaling of the radiative absorption coefficient with pool size

was investigated by performing vertical centerline traverses with propylene pool fires of 381 mm dia for fuel flow rates ranging from 230 to

1400 mil/s (18 to 110 kW fires) and of 762 mm dia for flow rates ranging

from 1300 to 3465 mJ£/s (102 to 273 kW fires). It was found that the

maximum values of the absorption coefficient scaled with the square of

"pool diameter so that the data for this set of measurements fell on a single graph when plotted against fuel flow velocity. An abrupt

72
decrease of slope of the plot above a velocity of 5 mm/s was tentatively

interpreted to correspond to the flow above which air cannot penetrate

to the pool surface.

The influence of fuel type was studied by performing: vertical cen- terline traverses with 50 kW 381. mm dia pool fires of ethane, propane

and eth.ylene in. addition to propylene. It was found that the logarithm

of the maximum absorption coefficient, correlated linearly with the

length of laminar diffusion flames at the soot point.. Although currently established only for a single rate of heat release and for four fuels,

this finding opens up the important possibility of predicting radiative

properties of large turbulent fires from data obtained with small laminar flames. A major portion of future work under this task will therefore be concerned with the extension of such correlations to a wider

range of fuels and burning conditions* Work currently under way has already shown that a similar correlation exists between the radiative

fraction of total heat release rate of turbulent fuel-jet diffusion

flames and soot-point flame, length of laminar flames.

Reports and Papers

1. Markstein, G.H. , ’’Measurements on Gaseous-Fuel Pool Fires with a Fiber-Optic Absorption Probe,” FMR.C Technical Report RC83-BT-1,

March 1983; also, paper to be presented at this conference.

Task 5 ; Flame Radiation from Charring Fuels

Task Leader : J. de Ris , R. L. Alpert

Technical Abstract

There is a demonstrated need for a standardized measurement to

characterize radiative emission from the flames of a burning material.

Such flame emission is the critical factor in determining material

flammability. Accordingly, a new. flammability apparatus employing a 0.3 m x 0.3 m vertical sample is being developed for the accurate measurement of heat transfer to a vertical surface above the sample and

flame emission- absorption coefficient and radiation temperature in this

region. Measurements of piloted ignition time, transient heat release

rates, and turbulent flame heights will also be obtainable. These

measurements will serve as an input to our recently developed analytical models^ * for the transient pyrolysis rate of charring materials

and for the critical conditions which allow charring materials to

undergo sustained burning and wind-aided flame spread- The calculated

critical conditions based on. measured properties of the ,3-m-high charring material should enable predictions to be made. .of. material flammability under a variety of end-use conditions.

Construction of the new flammability apparatus is not yet com-

~ plete. However, the instrument to be used for the critical flame radiation measurement in the heat feedback- region, has been constructed and

73
is ready for testing. This radiometer will simultaneously measure

flame absorption coefficient and radiation temperature profiles across

a two-dimensional wall fire. We have also been developing, in consultation with NBS personnel, a high- intensity, gas-fired radiant panel as an appropriate source of external radiation for the flammability apparatus .

In the program for theoretical prediction of material flammability

from property measurements, several analytic expressions were obtained

for the various stages of transient charring. These expressions are being used to infer effective charring properties from rate-of-heatrelease measurements. It is planned to compare the analytical expresJ :al solutions of a set of idealized equations

Reports and Papers

1. Delichatsios, M.A. and de Ris , Jr., "An Analytical Model for the

Pyrolysis of Charring Materials," paper to be presented at the

CIB Meeting, Sweden, May 1983.

2. Delichatsios, M.A. , "Critical Conditions for Sustained Burning,

and Flame Propagation on Vertical Charring Walls," paper submitted

for presentation at the ASME Winter Annual Meeting, Boston, MA,

November 1983.

3. Tamanini, F. , "A Numerical Model for One- Dimensional Heat Conduction with Pyrolysis in a Slab of Finite Thickness," Appendix A of

The Third Full-Scale Bedroom Fire Test of the Home Fire Project - Vol II," Ed. by A.T. Modak, Factory Mutual Research Corporation

Technical Report, Serial No. 21011.7, November 1976.

developed previously.

74
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : Harvard University

Grant No. : NB82NADA3030

Grant Title : The Prediction of Fire Dynamics

Principal

Investigators : Professor Howard W. Emmons Dr. Raymond Friedman

Division of Applied Sciences Factory Mutual Res. Corp.

Harvard University 1151 Boston-Providence Tn.

Pierce Hall Norwood, MA 02062

Cambridge, MA 02138

Other Professional Personnel : Dr. Henri E. Mitler, H.U.

Mr. Richard I. Land, H.U.

Mr. Arvind Atreya, Ph.D. Candidate, H.U.

NBS Scientific Officer : Dr. jQ hn Rockett

Task 1 : The Prediction of a Fire in an Enclosure

Task Leaders : Dr. H.E. Mitler, Prof. H.W. Emmons

Technical Abstract : An integral model analysis of the time-dependent ceiling-jet produced by the hot plume ascending from a fire in a corridor has been

published as a technical report. It is preliminary, because it makes

a number of simplifying assumptions, two of which are quite unrealistic: entrainment of the adjacent gas layer (air for the initial stages

and a hot layer for the later stages, for the confined-ceiling case)

has been neglected, as well as heat transfer to the surroundings. This

preliminary analysis already shows, however, that the buoyant acceleration of the "jet" is substantially greater than the Reynolds stresses

at the ceiling and confining walls, and that inertia cannot be ignored. Another interesting finding is that even for the steady-state

case, no analytic solution of the equations is possible when there is

friction. Hence a numerical technique must be used to solve the

coupled PDE's describing the flow. The method used here is a generalization of one developed by Lax and Wendroff. The results of this

limited analysis are reasonable, but well-known difficulties produced by the large gradients at the front end of the jet make the

technique less than wholly adequate, so that further refinements will

be required before the inclusion of more realistic physics is undertaken.

A restructured, multi-room version of Computer Fire Code V (Mark

5) was completed last year, and dubbed Mark 6. Not much has been done

with it since, except that a number of bugs have been found and fixed.

A "handbook" of materials properties needed by the model - mostly for

flammable materials - has been started, and incorporated for use by

75
Mark 6 as a separate file which can be accessed by the input program.

At the moment, it gives relevant thermophysical data for methane, propane, acetone, propanol, kerosene, heptane, methanol, PE, P.U. foam

#7004, POM, PMMA, PP, PS, red oak, and marinite.

A number of additions have been made to Mark 5, on the other hand.

Among them: the algorithms used there for convective heat transfer to

objects, walls, and ceiling were very crude, and there was none at all

for heat exchange between a heated floor and the adjacent - generally

cooler - layer. The latter is needed in order to permit the lower

layer to heat up (the other mechanism being mixing at the doorway)

.

Reasonably good though simple expressions were found from the literature for the convective heat transfer to horizontal surfaces, vertical

surfaces, floor, and lower and upper walls; these have been put into new algorithms. For the convective heating or cooling of horizontal

surfaces, it was found necessary to assume that the gas temperature

varies gradually from hot to cold in a transition zone (as is indeed

the case in reality). L. Cooper’s algorithm for the convective heat

transfer from a fire to a confined ceiling has been slightly simplified and generalized. Three of these algorithms have been incorporated

into a version now called Mark 5.2, and the rest will soon follow.

Mark 5.2 also has a photoelectric detector response algorithm now, as well as a much-improved contact-ignition algorithm. A forced-vent

algorithm was devised and inserted into the program as subroutine FORV.

Any desired time-dependent volumetric flow through that vent, V(t), can be approximated as a piecewise linear function, and is prescribed

through INPUT. VENT interpolates the values of V(t) at any time t, and

(as usual) finds the pressure in the room required to give that flow

through the unforced vent(s), which balances mass. Runs with this new algorithm are now (May 1983) being compared with a set of forced-vent

experiments carried out at Lawrence Livermore National Labs, and preliminary analysis is very promising.

Technical Reports and Papers

1. Mitler, H.E., "The Time-Dependent Ceiling-Jet in a Corridor,"

H.F.P. Technical Report #55 (Dec. 1982)

2. Emmons, H.W., "The Ingestion of Flames and Fire Gases into a Hole

in an Aircraft Cabin for Arbitrary Tilt Angles and Wind Speed,"

H.F.P. Technical Report #52 (1982)

3. Emmons, H.W.

,

"The Analysis of a Tragedy," to be published in F ire

Technology , NFPA (1983)

Task la : Pyrolysis, Ignition, and Fire Spread on Horizontal Surfaces

of Wood

Task Leader : Arvind Atreya

This study is an attempt to understand the complicated process of

transient fire growth on horizontal surfaces of wood and the related

phenomena of pyrolysis and ignition under the conditions of externally

76
supplied radiation. The anisotropic, inhomogeneous and charring properties of wood made this work especially challenging.

In this work, experimental techniques and methods were developed.

Numerous experiments on ten different kinds of wood were conducted

under various levels of external radiation, with the purpose of identifying the controlling mechanisms for spread, and to obtain reliable

chemical and physical data. The problem was divided into three com- ponents : (a) Solid phase thermal decomposition (PYROLYSIS)

(b) Conditions for flame spread (IGNITION)

(c) Heat and mass transfer to the unburned zone (FIRE SPREAD)

These component phenomena were then investigated both theoretically

and experimentally.

Finally, with the understanding of the controlling mechanisms

discovered for fire spread on wood, these component phenomena were

recombined to solve the overall transient fire spread problem. Since

we are now able to predict the flame radius as a function of time by

an appropriate transient flame spread theory, and mass flux by a pyrolysis theory, then the correlations of experimental results can serve as a basis of obtaining other physical and chemical quantities

of interest, like burning efficiencies, chemical species production

rates, etc.

Technical Reports and Papers

1. Atreya, Arvind, "Pyrolysis, Ignition, and Fire Spread on Horizontal Surfaces of Wood," Ph.D. Thesis, 1983.

77
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : National Fire Protection Association, Quincy, MA

Contract No. : EMW-C-0874

Contract Title : Investigation and Analysis of Major Fires

Principal Investigators : A. El wood Willey, Project Administrator

Thomas J. Klem, Division Director, Fire

Investigations and Applied

Research Division

Richard L. Best, Senior Fire Analysis

Speci al ist

Fire Investigations Department

National Fire Protection Association

Batterymarch Park

Quincy, MA 02269

(617) 328-9290

Other Professional Personnel : James R. Bell, Legislative Technical

Specialist

James K. Lathrop, Life Safety Code

Speci al ist

Wilbur Walls, Flammable Gases Specialist

Martin Henry, Flammable Liquids

Speci al ist

Charles E. Zimmerman, Fire Protection

Engi neer Robert Benedetti, Chemical Specialist

Robert Carter, Chief Fire and Arson

Investigations

Specialist

NBS Scientific Officer : Richard Bukowski

Edward Wall, Chairman, Working Group

United States Fire

Administration

Federal Emergency

Management Agency

National Emergency

Training Center

Technical Abstract : Under a cost-sharing contract between the

National Fire Protection Association, National Bureau of Standards and

Federal Emergency Management Agency, in-depth field investigations are

78
conducted of selected fire incidents. For each investigation an analysis is made of fire causal factors, spread factors, materials

contributing to fire and smoke propagation, people movement and

actions taken, fire propagation as a function of time, factors

affecting fire propagation, performance of fire protection equipment,

key life safety and property protection problems and of contributing

factors resulting in loss of life and property damage. In addition to

field work by investigators with fire protection engineering

background, other specialists are consulted, including NBS

researchers. In some cases, samples from fire scenes are tested for

fire hazard characteristics at NBS and results included in reports.

Briefings by fire investigators are provided FEMA/NBS regarding

incident facts and technical aspects of interest.

Following submittal of contract reports to FEMA/NBS, reports are published and distributed by NFPA to ensure that the facts and lessons

learned are made available to the fire community in a timely manner.

In addition to the literature, background data from the investigations

is available at NFPA for research purposes.

This contract is the sixth in a series of NFPA/NBS fire

investigation contracts since 1972. The four most recent contracts

have also involved the FEMA, with funding shared between the two

agencies and NFPA in a cooperative effort. Since the original

contract, 91 incidents have been investigated and reports" prepared.

Potential Applications

This in-depth investigation and analysis activity gives an improved understanding of fire growth and development, smoke

development and spread, and the actions of people in actual fire

situations. The information gained has many uses both in the fire

safety field and in the research community.

Reports contain commentary on the performance of fire detection

and extinguishing equipment, building assemblies and systems and

various measures of fire control. The studies provide an opportunity

to measure the performance of requirements in national consensus fire

safety codes and standards. Lessons learned from these investigations

are of use to fire safety practitioners and researchers. Indicators

for additional research are often included in reports.

In addition to the use of information by NFPA technical committees

and in technical programs, information from investigations is utilized

in training films and slide packages for use by the fire service and

fire safety practitioners.

79
Future Milestones

Investigations are in progress of six incidents and reports will

be prepared. These active studies include:

• An early morning fire in the Harrison County Jail in

Biloxi, Mississippi, on November 8, 1982, was responsible for the deaths of 29 inmates and injury to

59 others including inmates, jail officers, sheriff's

deputies, police officers and fire fighters. The fire,

reported to the Biloxi Fire Department at 1:31 a.m.,

originated in an occupied isolation cell. The isolation

cell walls and door were padded with a sprayed-on rigid

foam material tentatively identified as polyurethane

foam.

Although the fire was confined to the cell of origin,

thick, black smoke was able to spread rapidly throughout

the jail, trapping inmates in their cells. The jail

officer attempting to unlock cell doors to release

inmates was overcome in the smoke filled corridors.

The fire, of suspicious origin, was fed primarily by the

padding materials of the isolation cell. The rapid

spread of fire beyond the room of origin soon resulted

in untenable conditions throughout the jail. Delays

were experienced in the release of remaining prisoners

once the fire reached this magnitude.

• Gasoline vapors cascading from a storage tank during a filling operation in Newark, New Jersey on January 7,

1983 were ignited and ultimately resulted in several

small explosions and one large explosion. As a result,

an oil company employee was killed. Further, the

explosion resulted in the destruction of four gasoline

storage tanks and consumed approximately 3 million

gallons of gasoline before being brought under control.

The explosion occurred on Thursday, January 7, 1983

during a tank filling operation. The scheduled delivery

was for approximately 1.6 million gallons that would be

completed within approximately six hours. At the time

of the filling operation, two terminal operators visited

the tank as the expected fill time approached. Upon

arriving at the scene, the operators discovered that the

tank was overflowing. Terminal operators began the

emergency shut-down procedures for the tank. Sometime

during the fire department response to the scene.

80
ignition occurred. The blast had a great deal of force

in that a remote storage tank was flattened by the

impact. In- addition, other reported damage included

flattened railroad cars, destruction of a drum

refinishing plant, a truck terminal building, and the

destruction of several trucks and automobiles which were incinerated in the general area of the fire. In

addition, the impact of the blast damaged several

structures surrounding the industrial area.

• An early morning fire in the Jefferson Dormitory on the

campus of the College of William and Mary, Williamsburg,

Virginia, on January 20, 1983, forced the evacuation of

the building's 184 occupants into 15 degree Fahrenheit

weather and led to an estimated $4 million loss to the

structure and contents. Prompt reaction to the manual

fire alarm system and to the sounding of evacuation of

the dormitory resulted in no injuries to any of the

occupants. The fire was reported to the Williamsburg

Fire Department at 1:13 a.m. The fire spread through

the sprinklered building in concealed combustible spaces

beyond the reach of the building's sprinkler system.

Efforts of fire fighters to locate and extinguish fire

in concealed spaces above ceilings and behind wall

surfaces were unsuccessful. After approximately 2 hours

of interior fire fighting efforts, fire fighters were forced to withdraw from the building when the corridor

floor on the first floor collapsed and cracks formed in

the exterior bearing walls. The developing fire caused

the loss of the entire west wing of the building and all

of the attic and roof, with extensive damage to the

remaining east wing of the structure.

t An early morning fire in a community-based residential

facility (boarding home) resulted in six elderly

residents losing their lives. The fire occurred on Monday evening, February 7, 1983, in Eau Claire,

Wisconsin, a small college community 85 miles southeast

of the Minneapolis - St. Paul area. The building was a 100-year old Victori an-style, 2 1/2-story frame dwelling

which had recently been converted from a single family

structure to a boarding home. The facility provided

care for eleven elderly residents occupying rooms on the

first floor and second floor.

81
The cause of the fire is currently listed as undetermined by the Eau Claire Fire Department. The

investigation is continuing but it is believed to have

been an accidental ignition of furnishings. The fire

was discovered when one of the night managers was awakened by a smoke detector operating on the first

floor. Leaving her second floor room, and descending to

the first floor, she observed a developing fire within

the living room (lounge) portion of the building. At

the time of discovery, the manager could see a "glow" in

the area of a couch and feel the heat from the fire on her face. She returned to her second floor room to arouse the other night manager. A phone call was made

to the owner of the facility and evacuation procedures

were then initiated.

• Another in a long series of untreated wood-shingle roof

fires in Texas and Southern California occurred in

Dallas, Texas on March 21, 1983. The fire at the Willow

Creek Apartments in Dallas started in an unoccupied

apartment, caused by a malfunction of electrical wiring

in an exterior apartment wall. The fire spread upward

into the attic and advanced rapidly both internally and

externally along the roof. The fire spread to another

building downwind and against the wind to an adjoining

building to the north. The roof of the building to the

north had burned previously in August of 1980.

The Dallas Fire Department controlled the fire with a five-alarm response supplemented by two special calls

for equipment and with effective use of a helicopter for

observation. Four buildings were severely damaged.

Another seven buildings had minor roof damage or roof

spot fires that were extinguished. The preliminary

estimate of damage to approximately 125 apartments units was $6.6 mill ion.

Although the City of Dallas has an ordinance requiring

fire retardant Class C roofing on new construction, this

fire shows that the problem of untreated wood-shingle

roofs on existing buildings will continue in Dallas for

many years.

• A half-way house fire in Worcester, MA, resulted in 7 fatalities and injuries to 26 persons. Apparently, the

occupants of the half-way house were deinstitutionalized

mental patients from a nearby facility.

82
The fire, accidental in nature, was reported at 02:21 on the second floor of the converted single-family

dwelling, three stories in height. Early reports

indicate that the dwelling was a complying facility to

the lodging home occupancy of the State of Massachusetts

Building Code. There were smoke detectors and a fire

alarm system within the building.

Reports and Papers: Under this contract the following investigation

reports have been submitted to FEMA/NBS:

Bell, James R., "Rockefeller Park Towers - Cleveland, Ohio - January 5, 1982 - 5 Fatalities. (Summary Investigation)

Best, Richard, "Star Elementary School BLEVE - Spencer.

Oklahoma - January 19, 1982 - 7 Fatalities". (Limited

Investigation Report)

Bell, James R., Klem, Thomas J., and Willey, A. Elwood,

"Westchase Hilton Hotel - Houston, Texas - March 6, 1982 - 12

Fatal i ties."

Best, Richard L., "K Mart Corporation - Distribution Center

Fire - Falls Township, PA - June 21, 1982".

Bell, James R., "Dorothy Mae Apartment Hotel Fire - Los

Angeles, CA - September 4, 1982 - 25 Fatalities." (Summary

Investigation Report)

Bell, James R., "Perrys' Domiciliary Care Home - Pittsburgh,

PA - October 28, 1982 - 5 Fatalities." (Summary

Investigation Report)

Bryan, Dr. John L., "An Examination and Analysis of the

Dynamics of the Human Behavior in the Westchase Hilton Hotel

Fire, Houston, Texas on March 6, 1982".

Preliminary Reports

"The Westchase Hilton Hotel Fire, Houston, TX, March 6, 1982"

Publ ished Reports

Best, Richard L., Reconstruction of a Tragedy - Beverly Hills

Supper Club Fire, nFpA, 19/8.

83
Demers, David P., Fire In Syracuse: Four Fire Fighters Die,

NFPA, 1979.

A Study of the Baptist Towers Housing for the Elderly Fire,

NFPA, 19/3:

Best, Richard L. and David P. Demers, Investigation Report

on the MGM Grand Hotel Fire, Las Vegas, Nevada, November Zl,

1980, NFPA, 1982.

Bryan, John L., An Examination and Analysis of the Dynamics

of the Human Behavior in the MGM Grand Hotel Fire, Clark

County, Nevada, November 21, 1980 , NFPA, 1982.

Bell, James R., Klem, Thomas J. and Willey, A. Elwood, . Investigation Report, Westchase Hilton Hotel Fire, Houston,

Texas, March 6, 1982 , NFPA, 1982.

Bryan, John L., An Examination and Analysis of the Dynamics

of the Human Behavior in the Westchase Hilton Hotel Fire,

Houston, Texas on March 6, 1982 , NFPA, (Publication pending).

Swartz, J. A., Fahy, R. F. et al , Final Technical Report on the Building Fire Simulation Model, NFPA, 1983.

Articles in NFPA Publications

Fire Investigations Department. "Fire at the MGM Grand." Fire Journal

January 1982.

Fire Investigations Department. "Investigation Report on the Las Vegas

Hilton Hotel Fire." Fire Journal , January 1982.

Bryan, John L. "Human Behavior in the MGM Grand Hotel Fire." F ire

Journal , March 1982.

Hill, Steven. "19 Die in Chicago Hotel Fire." F ire Journal , March 1982.

Bell, James R. "Investigation Report of the Fire at Stouffer's Inn of

Westchester." F ire Journal , May 1982.

Fire Investigations Department. "The MGM Hotel Fire - Part 1." Fire

Service Today , January 1982.

Fire Investigations Department. "The MGM Hotel Fire - Part 2." Fire

Servi ce Today , February 1982.

84
Fire Investigations Department. "Hilton Fire: A Tragedy Revisited."

Fire Servi ce Today , March 1982.

Fire Investigations Department. "Westchase Hilton Fire Claims 12 - A Preliminary Report." Fire Servi ce Today , July 1982.

McKiernan, James V. and Peterson, Carl E. "The Lynn Conflagration - Part 1." Fire Service Today , July 1982.

McKiernan, James V. and Peterson, Carl E. "The Lynn Conflagration - Part 2." Fire Servi ce Today , August 1982.

Best, Richard L. and Walls, Wilbur L. "Hot Water Heater BLEVE in

School Kills Seven." Fire Journal , September 1982.

Fire Investigations Department. "Tragedy in Kentucky" (Beverly Hills

Supper Club). F i re Journal , November 1982.

Fire Investigations Department. "Fire at the MGM Grand Hotel." Fire

Journal , November 1982.

Fire Investigations and Applied Research Division. "Westchase Hilton

Investigation. " Fire Servi ce Today , January 1983.

Bell, James R., Klem, Thomas J. and Willey, A. Elwood. "Twelve Die in

Fire at Westchase Hilton Hotel." Fire Journal , January 1983.

Fire Investigations and Applied Research Division. "K Mart:

Sprinklers vs. Aerosols." Fire Service Today , March 1983.

Best, Richard. "$100 Million Fire in K Mart Distribution Center. "Fire

Journal , March 1983.

Bell, James R. "Five Die in Rockefeller Part Towers Fire, Cleveland,

OH." Fire Journal , March 1983.

Bell, James R. "24 Die in Los Angeles Residential Apartment Fire."

Fire Journal , May 1983.

Best, Richard. "Fire Walls That Failed: The K Mart Corporation

Distribution Center Fire." Fire Journal

,

May 1983.

85
Recent Papers

Willey, A. Elwood, "Lessons from Recent Hotel Fires",

presented before the Opening Session, May 18, 1981, at the

85th NFPA Annual Meeting, Dallas, TX.

Best, Richard L., "Mississauga Train Derailment", presented

at the Annual Meeting of the Union of Furtherance of Fire

Protection, Leverkusen, Germany, June 16, 1981.

Willey, A. Elwood, "A Prel imi nary Report - The Westchase

Hilton Hotel Fire, Houston, Texas, March 6, 1982", paper

presented at the Opening General Session, 86th NFPA Annual

Meeting, San Francisco, CA, May 17, 1982.

Case Study NFPA Films and Slide Packages based on contract

investi gati ons:

Case Study Slide Packages:

SL - 13, "LP-Gas Explosion, Kingman, Arizona, July 5, 1973"

SL - 22, "Hospital Fire, Osceola, MO., December 3, 1974"

SL - 26, "Three Nursing Home Fires" (Wincrest Nursing

Home, Chicago, Illinois, January 30, 1976;

Cermack House, Cicero, Illinois, February 4,

1976; Plaza Nursing Centre, Niles, Illinois,

February 18, 1976)

SL - 38, "Reconstruction of a Tragedy - The Beverly

Hills Supper Club Fire"

"Four Hotel Fires: An Investigative Analysis", Fire

Investigations and Applied Research Division

F i 1 ms

:

FL - 35, "Incendio!" (High-rise fire, Sao Paulo, Brazil,

February 1, 1974)

FL - 50, "The Beverly Hills Supper Club Fire ... A

Case for Code Enforcement"

FL - 58, "Fire at the MGM Grand"

86
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : The Pennsylvania State University

Grant Number : NB81NADA2044

Grant Title : An Investigation of Turbulent Fires on Vertical and

Inclined Walls

Principal Investigator : Professor G. M. Faeth

Department of Mechanical Engineering

The Pennsylvania State University

214 Mechanical Engineering Building

University Park, PA 16802

Other Professional Personnel : S-M.. Jeng, Research Assistant

M-C. Lai, Graduate Assistant

NBS Scientific Officer: H. Baum

Technical Abstract

Introduction - The objective of this investigation is to study the

structure and radiation properties of turbulent fires along walls at

various inclinations. The findings can be applied to modeling fires

within structures, the development of material test codes and the

development of fire detectors.

Measurements in both noncombusting and combusting flows along

plain surfaces are used to evaluate models of mean and turbulent

structure as well as flame radiation properties. Correlations of the

results, useful for comprehensive fire models, are also being sought.

Combusting flows are emphasized—noncombusting flows are considered to

provide systematic model evaluation. Various wall inclinations provide

information on stratification—an important aspect of fires within

structures

.

During this report period, test apparatus was assembled for measurements in noncombusting buoyant flows along surfaces and measurements

were initiated. Earlier work with axisymmetric flames was also

extended—to aid development of theoretical and experimental techniques.

Apparatus - An infrared monochrometer system (1.8 - 5.5 microns) was developed to measure spectral radiation intensities from flames.

Satisfactory operation was verified by initial measurements in axisymmetric flames.

The apparatus for studying noncombusting buoyant flows along

surfaces was developed. To avoid errors due to parasitic heat losses

in thermal plumes , these buoyant flows are formed with mixtures of air

87
and sulfur hexafluoride or carbon dioxide. Mean and fluctuating velocities are measured using laser Doppler anemometry. Mean and fluctuating

concentrations are measured by Rayleigh scattering. Both techniques are nonintrusive and have excellent frequency response.

Theory - The analysis is based on numerical solution of the boundary layer equations. The conserved-scalar method is used in conjunction

with a k-e-g turbulence model. The original version of this model was converted to Favre averaging and recalibrated successfully so that a single set of empirical constants applies for both noncombusting and

combusting flows.

State relationships giving scalar properties as a function of

instantaneous mixture fraction are needed for analysis. Two methods

are being considered: (1) the laminar flamelet method—where properties

are found by measurements in laminar diffusion flames; and (2) the

partial equilibrium method—where properties are found assuming thermodynamic equilibrium for fuel equivalence ratios less than some critical

value and frozen adiabatic mixing for high fuel equivalence ratios.

A narrow-band radiation model is used to predict spectral radiation

intensities. The Goody statistical model, in conjunction with the

Curtis-Godson approximation for nonhomogeneous radiation paths, is

used. Two methods of treating turbulent fluctuations are being examined: (1) use of mean properties—ignoring turbulent fluctuations;

and (2) use of a stochastic model where turbulent fluctuations are treated by random sampling.

Results and Discussion - Predictions of scalar properties using

the laminar flamelet method were in good agreement with earlier measurements in buoyant methane flames. 3ased on these present findings,

the laminar flamelet method has good potential for predictions of

temperature and the concentrations of major gas species in flames. The

partial equilibrium method yielded fair results for the same properties

when thermodynamic equilibrium was frozen at a fuel equivalence ratio

of 1.2. While less effective, the partial equilibrium approach should

be valuable in frequent instances where laminar flame data is unavailable for a particular fuel.

Figure 1 is an illustration of predicted and measured monochromatic

spectral radiation intensities in a highly buoyant, axisymmetric turbulent methane diffusion flame. This flame appears yellow to the eye

and contains measurable quantities of soot, but effects of continuum

radiation from soot are small. Therefore, gaseous radiation bands at

1.88 microns (H 2O) , 2.7 microns (CO? and H2O) and 4.3 microns (CO2 ) are clearly evident. The results are for a radial path at the flame

tip—where the mean temperature along the axis is a maximum

.

Three predictions are illustrated in Fig. 1, based on: (1) measured mean properties; (2) mean properties using the laminar flamelet

method; and (3) fluctuating properties using the laminar flamelet

method and the stochastic analysis. Predictions based on stochastic

88
analysis are reasonably good—which is most encouraging. Predictions

based on mean properties are lower than both the stochastic analysis

and the measurements. This is expected, since radiation is not a linear property in flames; therefore, mean radiation levels are not

properly functions of mean properties alone.

Both measurements and analysis indicate that spectral intensities

increase when burner flow rates are increased in buoyant flames —in

agreement with earlier findings of Markstein.

Conclusions - The present Favre-averaged, k-e-g model provides

reasonable predictions of flow structure for flows ranging from forced

constant density jets to buoyant flames—with a single set of empirical

constants. The laminar flamelet method is promising as a method for

handling effects of finite-rate chemistry and differential diffusion in

turbulent flames—circumventing near-term difficulties in analyzing

turbulent reacting flows. The partial equilibrium method is useful

for the many instances where laminar flame data is unavailable.

The structure predictions yielded reasonably good predictions of

nonluminous flame radiation properties in conjunction with the stochastic analysis which allows for effects of turbulent fluctuations.

As expected, use of predicted or measured mean properties caused

radiation intensities to be underestimated.

These methods established for axisymmetric flames are now being

applied to fires along surfaces. Measurements are currently in progress for noncombusting flows to initiate model evaluation

Reports and Papers

Jeng, S-M. , Chen, L-D. and Faeth, G. M. , "The Structure of Buoyant

Methane and Propane Diffusion Flames," Nineteenth Symposium

(International) on Combustion , The Combustion Institute, Pittsburgh,

pp. 349-358, 1982.

Jeng, S-M., Chen, L-D. and Faeth, G. M. , "Predictions and Measurements

of Turbulence Properties in Buoyant Diffusion Flames," Proceedings of

the Fifteenth Fall Technical Meeting , Eastern Section of The

Combustion Institute, Pittsburgh, pp. 31.1-4, 1982.

Jeng, S-M., Chen, L-D. and Faeth, G. M. , "The Structure of Axisymmetric

Buoyant Diffusion Flames," Report No. NBS-GCR-83-422 , February 1983.

89
( mo - is - mo/rt) HDMVienra

1“ O

90

WAVELENGTH

,

|im

Fig.

1

-

Spectral

radiation

intensities.
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution: Princeton University

Contract Number: NB83NADAU00

T

Contract Title: Flow Field Effects on the Sooting Structure of Dif

fusion Flames

Principal Investigators: Ian M. Kennedy Irvin Glassman and

Research Staff Member Professor

Frederick L. Diyer

Professor

Department of Mechanical and Aerospace

Engineering

Princeton University

Princeton, New Jersey 085^

NBS Scientific Officer: Bernard McCaffrey

Technical Abstract

In major, as well as minor, fire conflagrations, smoke inhalation

is a primary contributor to the casualty rate. The particulate matter

in smoke is soot formed during the burning of the fuel mass in a diffusion controlled combustion system. Earlier Princeton work on soot

formation in both pre-mixed and diffusion controlled combustion systems

has established the fuel pyrolysis rate as a dominant factor in a system's propensity to soot. It follows then that temperature is an important parameter with regard to a combustible material's tendency to

soot. However, it is the time that a fluid element is exposed to

pyrolysis temperatures in a flame that determines the amount of

particulate matter formed. This time, and other factors in flame

configurations, are controlled by the overall flow situation in the

combustion system. In order to evaluate how control of the fluid

mechanical situation could affect the extent (and character) of the

soot process, the present program was undertaken.

As inferred, the production of soot in diffusion flames can be

influenced significantly by the flow field in and around a flame. The

convection of particles by the flow can also determine their residence

time in regions of growth and oxidation and, in addition, in many

experimental configurations the fuel stream entrains oxidizer at the

base of the burner. These latter effects serve to complicate the

interpretation of soot measurements in arrangements such as WolfhardParker and tubular burners. Consequently, it is necessary to have a well-controlled and well-defined flow field in which the interaction of

fluid flow and chemistry on soot production in a diffusion flame can be

clearly elucidated. Thus we have chosen the following "opposed jet"

91
diffusion flame configuration.

Fuel is ejected uniformly from a porous cylindrical, ceramic

burner which is housed in a low turbulence wind tunnel supplied with

oxygen and nitrogen. A laminar diffusion flame is stabilized in the

forward stagnation region of the burner. Measurements of the flow and

temperature fields are obtained along the stagnation streamline with an

LDV system and a radiation-corrected thermocouple. A laser light

scattering - extinction measurement yields data on soot particle number

density, particle size and soot volume fraction. Measurements of the

soot characteristics are made along the stagnation streamline from

their region of formation on the fuel side of the flame up to the

stagnation point. Along the stagnation streamline the flow is onedimensional and the velocity data permit the interpretation of the

light scattering measurements in terms of time rather than distance.

Consequently, rates of formation, surface growth and coagulation in the

diffusion flame can be inferred from the data. More complex, twodimensional flow fields do not readily permit the interpretation of

soot behavior in these terms.

Measurements have been made on the effect of varying the oxygen

index (the oxygen mole fraction) in the oxidizer flow. The initial

fuels chosen were ethene and propane and the oxygen index range

selected varied from 0.18 to 0.28. Maximum flame temperatures

increased about 400° K over this range of oxygen concentration. From

the experiments soot volume fractions were found to increased by an order of magnitude with increasing oxygen index.

Concisely, the results to date obtained from the light scattering

data reveal that with increasing oxygen index there is a) an increase

in the number density of particles at all locations, b) an increase in

the soot volume fraction at all locations, c) a maximum soot particle

diameter near the stagnation point which is unchanged at around 60 nm,

and d) an increase in the soot production rate (rate of increase of

soot volume fraction) at any given location.

The one-dimensional nature of the flow along the streamline also

permits the calculation of soot volume fraction growth rates. In the

absence of significant particle generation, which appears to be the

case at the locations of interest, the measurements yield an indication

of surface growth rates for soot particles. Apparent values of surface

growth rates are around 10”3 g/cm -sec near the flame front, and this

value decreases by about a factor of 5 towards the stagnation point.

These results reflect the well-known decrease in apparent surface

reactivity of soot particles as they age. In addition, there is a trend to higher surface growth rates as the oxygen index is increased.

Arrhenius-type plots of overall soot volume increase through the

flame against a reciprocal average temperature have yielded typical

values for the apparent activation energy. The activation energies

were 48 kcal/mole for ethene and 20 kcal/mcle for propane.

Reports and Papers

Kennedy, I.M., Vandsburger, U. , Dryer, F.L. and Glassman, I., "Soot

Formation in the Forward Stagnation Region of a Porous Cylinder",

Western States Section/Combustion Institute Paper 82-39, 1982.

92
Vandsburger, U. , Kennedy, I.M. , Dryer, F.L. and Glassman, I., "The

Effect of Oxygen Index on the Sooting Structure of a Diffusion Flame",

Eastern States Section/Combustion Institute Meeting, Pane*" No* 3, 1932.

93
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : SRI International

Contract Number : NB81NAHA2005

Contract Title : Continued Development of Residential Fire Decision

Analysis Model

Principal Investigator : Fred L. Offensend, Ph.D.

Director, Decision Analysis Department

SRI International

Menlo Park, California

Other Professional Personnel : Ann J. Pacey

Senior Systems Analyst

SRI International

Menlo Park, California

NBS Scientific Officer : Alan Gomberg

Technical Abstract :

The objective of this project is to develop and demonstrate a decision analysis model for evaluating residential fire loss reduction

strategies. The modeling approaches developed for this project are to

contribute to CFR' s more general effort to develop fire risk assessment

methodology.

The decision analysis model provides an analytic framework for

evaluating loss reduction strategies. The framework includes a loss

model for calculating deaths, injuries, and property losses under various intervention strategies. A cost model calculates the costs of

implementing each alternative. From an economic standpoint, the most

attractive alternative is the one that results in the least cost plus

loss

The rudiments of the fire loss model were developed in late FY 82.

Most of the work this past year has been spent refining and verifying

the model. The model is now functional and is being used to evaluate

several alternatives, including conventional sprinklers, fast-response

sprinklers, and smoke detectors. Other alternatives will be evaluated

as time permits.

The loss model represents a major breakthrough in fire loss modeling. Most previous models have calculated fire losses as a direct

function of final flame extent. Whereas this is a reasonable approach

for property losses, it is unsatisfactory for fatalities, as many deaths occur during the early stages of a fire. The deficiency is especially

94
apparent when modeling the impact of alternatives which reduce the extent

of fire damage, but which have little effect on life safety.

The innovative feature of our fire loss model is the representation

of critical events in a fire and the modeling when fatalities occur by

critical event. Critical events are defined as key changes in fire con- ditions such as occurrence of flashover or major changes in suppression

systems status such as sprinkler operation. Algorithms have been developed to combine NFIRS casualty data with expert judgment to distribute

the fire losses according to the critical event at which they occurred.

Other NFIRS statistics are used in conjunction with the same algorithms

to determine the fire growth transition probabilities between critical

events. Alternatives are modeled by adjusting the transition probabilities to reflect the action of the intervention strategy in question.

The model has been tested and calibrated using 1980-81 NFIRS data.

Results are being reviewed by interested parties. A final report will

be issued in late 1983.

Reports and Papers :

Gomberg, A., Buchbinder, B., and Offensend, F. , "Evaluating Alternative

Strategies for Reducing Residential Fire Loss—The Fire Loss Model,"

Interim Report, National Bureau of Standards, NBSIR 82, Summer 1982.

Gomberg, A., and Offensend, F., "Evaluating Fire Safety Alternatives: A

Probabilistic Approach to Decision Making," paper presented- at annual

NFPA meeting, St. Louis, Missouri, May 1983.

95
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : SRI International

Grant No . : NBS Grant NB80NADA1003

Grant Title : Polymer Degradation During Combustion

Principal Investigator : Dr. S. K. Brauman

Polymer Sciences

SRI International

333 Ravenswood Avenue

Menlo Park, CA 94025

NBS Scientific Officer : Thomas J. Ohlemiller

Technical Abstract

The degradation of burning polymers is being investigated to

provide understanding of the detailed degradation processes occurring in

the condensed phase of a burning polymer that result in fuel production

and to allow prediction of the effect of certain thermal or chemical

variables on the rate or mechanism of fuel production. We are using a novel driven- rod apparatus with superimposed radiant heating to study

steady-state linear regression of vertically mounted polymer rods

degrading under nonflaming conditions that simulate those of combustion.

Absence of the flame simplifies experiments and analysis.

Previously, we used this driven-rod, radiant pyrolysis technique to

study steady-state linear regression of vertically mounted polystyrene

rods degrading under nonflaming conditions that simulate those of

combustion. Using this technique, we demonstrated that a combustion

process can be successfully isolated and simplified for detailed study.

The same mass loss rate (0.06 cm/min) and temperature-depth profile

(surface temperature T = 446° ± 3°C) obtained for combustion of polystyrene in air in the Hriven-rod configuration were achieved for nonflaming pyrolysis of polystyrene in air and nitrogen by using superimposed radiant heating. The required radiant flux is independent of

the atmosphere, indicating that polymer surface oxidation is unimportant

during pyrolysis and, presumably, during combustion. The lack of oxygen

incorporation in the pyrolysis residues substantiates this conclusion.

Furthermore, we successfully calculated the observed mass loss or fuel

production rate using the temperature-depth profile and gravimetric

kinetic parameters obtained isothermally under slow heating conditions

in an inert atmosphere. The success of these calculations

coupled with the observed monomer- to-nonmonomer ratio (33:67) in the

volatile pyrolysis products indicates that the mechanism of degradation

of polystyrene under our combustion conditions is similar to that under

96
more conventional slow-heating conditions in the absence of air.

During the present year, determination of the high-boiling volatile

products and the heat of gasification concluded our studies on polystyrene. To identify the composition of the fuel entering the flame

during combustion, we analyzed all the products volatilized from the

surface under our combustion-like (nitrogen) radiant pyrolysis conditions. The high-boiling volatiles were identified by field ionization

mass spectrometry (FIMS). Oligomers as high as heptamer are detected;

volatile products larger than tetramer have not been reported previously.

The trend for distribution of monomer, dimer and trimer (monomer > trimer > dimer) has been observed previously for certain pyrolysis

conditions. Based on the FIMS results, the molecular weight of

volatiles for the mass range 100-800 is M = 220, M = 289.

The heat of gasification, L, for polystyrene was determined from

the dependence of the mass loss rate on the incident flux. The heat of

gasification (472 cal/g or 1.98 kJ/g) generally agrees with other values

available in the literature for polystyrene.

The investigation of polypropylene was initiated during the current

year, and steady-state combustion and radiant pyrolysis studies have

been completed. In contrast to the results for polystyrene, oxidation

is important in the condensed phase degradation of polypropylene burning

in this configuration. Thus, we are unable to make the pyrolysis and

combustion temperature profiles very similar for the desired mass loss

rate. Compared to the combustion profile, the air pyrolysis profiles

are low and the nitrogen pyrolysis profiles are very high. Agreement

between calculated and observed rates for radiant pyrolysis in nitrogen

is excellent, however, agreement is poor for both air pyrolysis and

combustion using kinetic parameters for air or nitrogen. The oxygen

involvement implied by this poor agreement is further substantiated by

the finding of oxygen incorporation in the combustion residue.

The information obtained from this research will contribute to

reducing the nation's fire loss by providing understanding of the

chemistry of the combustion process of fuel production. With this

knowledge, understanding of the effectiveness of and even prediction of

improved fire retardants used to control fires by altering fuel

production become possible.

Reports and Papers

Brauman, S. K. , Matzinger, D. P., and Berg, R. A., "Polymer Degradation

During Combustion," SRI International Annual Report, April 11, 1983.

Brauman, S. K. , Chen, I. J. , and Matzinger, D. P., "Polystyrene Degradation During Combustion," J. Polym. Sci., Polym. Chem. Ed., 21 , 000

(1983).

97
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : TRW

Contract Number : NB82SBCA1662

Contract Title : Modeling of Wind-Aided Flame Spread

Principal Investigator : Francis Fendell

Engineering Sciences Laboratory

TRW Space and Technology Group

Redondo Beach, CA, 90278

Other Professional Personnel : George Carrier, Harvard University

Phillip Feldman and Stanton Fink, TRW

NBS Scientific Officer : Howard Baum

Technical Abstract

1. Introduction . A major goal of fire dynamics is prediction of the rate

of fire spread from knowledge of (1) the physicochemical properties of the

combustible materials and (2) the thermohydrodynamic environment. Flamepropagation rates become particularly significant under wind-aided con- ditions; in general, far more rapid fire advance is associated with situations in which hot gaseous products of homogeneous combustion preheat

(by conduction, convection, and/or radiation) still uninvolved downwind

combustible materials. In contrast, in spread against the wind, fire ad- vance usually is much slower because combustion products flow over already involved portions of the combustibles, and only gas-phase radiation

and solid-phase conduction can effect preheating.

With the more rapid advance connected with wind-aiding, quasisteady

approximation tends to be inadequate and explicit accounting for temporal derivatives is required; thus, even the simplest scenarios in windaiding spread entail dependence on two spatial coordinates and on time.

Accordingly, progress to date in quantifying wind-aided flame spread is

modest. Here, the goal is to provide enough quantitative accuracy to

permit correct ordering of materials with respect to supporting of fire

spread, even if the predicted rate of spread is not precise. It may be

worth noting that consistent orderings of materials, but not precise

quantitative values, are reproduced by purportedly standardized laboratory testing of materials in a severe fire environment.

At the rudimentary present state of quantitative analysis, there

are three geometric arrangements that would appear to warrant attention.

One may distinguish usefully (1) fire spread across a horizontal solid

slab constituting the ceiling of a room or corridor, such that forcedconvection arising from a boundary constraint is the source of the aiding

wind; (2) fire spread up a vertical wall, such that free convection is a source of the aiding wind; and (3) fire spread across a horizontal solid

slab constituting the floor of a room or corridor or forest, such that a boundary constraint is the source of the aiding wind but buoyancy plays

98
a crucial role. While perhaps the first two cases are of primary interest within a structure and while perhaps the third case is of primary

interest in wildlands and in spread between structures, nevertheless comparing the cases is mutually illuminating. Of course, the generalities

presented here find many exceptions; for example, the torching out of a single tree in a so-called passive crown fire entails many features in common with case (2). In this discussion, primary attention is to be

placed on case (1), which (for all its difficulties) may be the most

straightforward of the three cases, and which seems the most tractable of

the three cases. Space precludes comments concerning the other two, less

advanced cases. However, before any of the cases are discussed, some

general remarks on formulation are apropos.

2. Formul ation . A formulation is sought in which all the significant

phenomena are incorporated in the simplest reasonable form, such that

convection, diffusion, radiative transfer, chemical exothermicity, buoyancy, pyrolysis, char formation, and char erosion are all treated to a comparable degree of accuracy. The framework for such a formulation is

furnished by the so-called Shvab-Zel dovich approximation, in which the

dynamics and energetics are decoupled as much as reasonably possible, and

in which a generic fuel vapor is taken to react exothermically with oxygen in a direct one-step irreversible rapid homogeneous chemical reaction.

One advantage introduced by wind-aiding is that the flow speeds, and

hence the Reynolds number, tend to be large enough to permit adoption of

the boundary-! ayer approximation: diffusion transverse to streaming is

retained, but diffusion in the streamwise direction may be omitted, in

the lowest order of approximation. Furthermore, with the streaming well

defined, it is possible to approximate convective transport of mass, momentum, and heat in the manner of Oseen; that is, it is possible to linearize the streamwise convective transport . It should be noted, however,

that in free-burning problems, in which the fuel vapor usually is either

pyrolyzed from a solid or evaporated from a liquid pool, the convective

transport transverse to the principal streaming warrants careful treatment. Indeed, where there is interphase mass transfer (at a rate that

appears as an eigenfunction to be identified in the course of solution),

the convective transport transverse to streaming entail s nonl ineari tv .

The conventional Shvab-Zel dovich formulation concerns gas-phase phe- nomena. A consistent level of accuracy is required for the formulation

of the solid phase. It is suggested here that the often-adopted twoparameter (gasification temperature, specific endothermic heat of gasification), sublimation-type (or evaporation-type) model of gasification

may not be adequate to recover behavior of a char-forming body. Upon

heating to a fairly well-defined temperature, the preponderance of synthetic and natural polymers undergo thermal degradation partially to a carbonaceous, porous matrix, and partially to (in part, combustible) vapor that traverses the (usually relatively thin) porous matrix to reach

the gas phase. The heat-retention properties of the matrix are crucial

under forced-convection-extinction conditions, and probably warrant re- tention under vigorous-burning conditions as well. Furthermore, at highenough temperature, the carbonaceous char layer erodes; this may be owing

99
to loss of mechanical strength such that spalling occurs, or it may be

due to chemical attack (such as reduction by the char of carbon dioxide,

and, to a lesser degree, of water vapor). In any case, the char layer

tends not to increase indefinitely in thickness, but to remain thin relative to the depth of the gas phase and of the pristine solid (such that

an approximate integral -type treatment of the char layer suffices). The

point to be emphasized is that a formulation, consistent with the Shvab-Zeldovich spirit, is available that encompasses the usually endothermic onset of char formation and gasification, the onset of char erosion, and

the heat-retention properties of the char, but that does not introduce

spatially distributed, finite-rate processes of uncertain rate and mechanism and of limited generality.

Radiative transfer involves reradiative cooling of the gas-solid interface, radiative heating of the gas-solid interface from cooling of

vitiated bulk-gas air, and radiative heating of the gas-solid interface

from nonconductive transport from the gas-phase flame (probably in the

presence of soot). It is the last of these three processes that probably

presents the greatest challenge in seeking a compromise between fidelity

to the physics and tractability of the formulation. In this regard, the

recent work of Howard Baum of the Center for Fire Research is noteworthy.

In summary, wind-aided flame challenges modeler to incorporate trac

table formulation of charring and radiative transfer in an explicitly unsteady, spatially (at least) two-dimensional problem involving close coup

ling of the solid and gas domains.

3. The Ceiling Geometry . Wind-aided flame spread along a thick semiinfinite horizontal slab (such that burn-through, and thus exhaustion of

outgassing capacity, is not achieved), entails a parabolic boundary/initial-value problem. In particular, one may envision the initiation of a hot vitiated air stream over the leading edge at time zero, displacing

the prior stagnant, thermodynamical ly benign environment downwind. One

seeks the rate at which the char-formation front at the solid-gas interface, and the rate at which the char-erosion front at the solid-gas interface, progress downwind, as a function of the thermohydrodynamic environment and the physicochemical slab properties; these fronts characterize

the extent of slab "involvement". While knowledge of the progression

rates of these fronts does not constitute a complete solution throughout

the three-independent-variable space, such knowledge does provide the

knowledge of particular engineering significance, and theoretical ly one

can later ascertain meticulous details if one wishes.

Either by use of point-source solution for a second-order parabolic

operator, or alternatively by Weiner-Hopf-1 i ke arguments in the inversion

of Fourier transforms, Vol terra integral equations have been derived that

relate the dependent variables and their fluxes in the gas-solid interfacial plane ; of course, such relations reduce the three-independentvariable problem to a two-independent-variable (time and streamwise distance) problem. These integral equations are supplemented by locally

appropriate algebraic relations between the dependent variable and their

fluxes in the interfacial plane; the phrase locally appropriate alludes

100
to the fact that different algebraic relations pertain to the preheat,

char formation, and char erosion zones. The integral equations are also

supplemented by an ordinary differential equation, evolved from a transversely averaged (i.e., approximate integral -type) treatment of the con- servation-of-energy equation for the (relatively thin) char layer. In

fact, the problem as rephrased in the interfacial plane is of hyperbolic

character, with fluid-particle paths and fixed downwind stations delineating a characteristics grid on which the char-formation front and charerosion front are shock-Tike loci, i.e., loci noncoincident in general

with a characteristic curve. Cauchy (boundary) data, specified along the

boundaries of the two-dimensional ( streamwise-distance/time) solution

space, is propagated across the characteristics mesh in customary, nodeto-node, stepwise procedure (with iteration).

The boundary data consists partly of the temporal (downwind) history

of the first hot particle of vitiated-air flow across the leading edge at

the. starting instant; the requisite Abel integral equation is treated by

known procedures. The boundary data consists partly of the selfsimilar

solution to the steady flow past a semi-infinite, fully involved charring

slab (in the absence of any radiative transfer); this steady solution

holds instantaneously at the leading edge (since there is no upwind transfer of information in the formulation). Solution to this generalized Em- mons problem has been thoroughly explored, not only because it furnishes

requisite boundary data for initiating the complete solution for all sites

and times in the interfacial plane, but also because it permits solution

even upon relaxation of approximations required for tractability under

nonselfsimilar conditions. For example, it is possible to -investigate the

consequences attendant on adoption of the Oseen approximation of convective transport, of Lewis-Semenov number unity, of approximate integral

treatment (rather than exact treatment) of the char layer, of a sublimating pseudomechanism (rather than diffusively controlled chemical reduction) for char erosion, etc. The findings, documented in a publication

listed below, are, succinctly, that none of the approximations compromise

trends at all, but quantitative precision is sacrificed.

Attention is now being turned to propagating the solution across the

characteristics mesh, so that the variation of rate of fire spread with

physical parameters (gas-phase flow speed, pristine solid heat capacity,

etc.) may be ascertained.

In the presentation comments about the anticipated adaptability of

the formalism to spread up a vertical wall, but the major modification

required for wind-aided spread along a floor slab, will be included.

Reports and Papers

Carrier, G., Fendell , F., and Fink, S. (1983), "Towards Wind-Aided Flame

Spread Along a Horizontal Charring Slab: The Steady-Flow Problem," Combustion Science and Technology 32., 161-210.

Carrier, G. and Fendell, F. (1982), "Crown Fires," Report 38095-6001 -UT00, TRW Space and Technology Group, Redondo Beach, CA, October.

101
CENTER FDR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution: University of California, Berkeley

Grant No : NB81 NAHA 2038

Grant Title : "Dynamics of Smoke and Inert Tracers Produced in Porous

Fuels

Principal Investigator: Professor Simon L. Goren

Department of Chemical Engineering

University of California

Berkeley, California 94720

Other Professional Personnel:

Warren Friedman, Postdoctoral ?_e search Assistant

Peter Lipowicz , Graduate Research Assistant

NBS Scientific Officer: Dr. George Mulholland

Technical Abstract:

The objective of this research is to quantify the mass generation rate and the size distribution of smoke aerosols produced

by smoldering porous fuels. These variables are to be related to the

chemical and physical properties of the fuel and to the combustion

conditions. Since temperature, gas velocity and location of

pyrolysis change during the course of smoldering, the amount and

other characteristics of the emitted smoke also vary with time. Our

approach to this dynamic process is a coordinated theoretical and

experimental study.

Time dependent rates of release and size distributions of smoke

aerosols produced by smoldering cellulosic insulation are being

measured. The fuel is supported on an array of screens in a pyrex

combustion chamber 178 ram in diameter and 330 mm in length. Air is

introduced below the screens and caused to flow upwards through the

fuel. Most of the combustion gases are vented to a hood through a chimney. A small sample of the gases is withdrawn and diluted for

analysis by a Royco model 236 Laser Particle Counter. This

instrument counts the particles and sorts the counts according to

size into sixteen channels; the smallest detectable particle is 0.12

pm in diameter. Because of the high concentration of smoke, we had

to design a sampler which permits dilutions of 100 to 10,000 fold.

The chamber has an array for ports for insertion of thermocouples

into the fuel to monitor the pyrolysis propagation rate. The output

from the Royco and the thermocouples are recorded at about one minute

intervals by a microcomputer and are stored on floppy disk. We will

be recording the concentrations of oxygen, carbon monoxide, carbon

dioxide and water vapor using various instruments and also the mass

102
loss of the fuel using a load cell. The mass of smoke emitted is

measured at several times during the course of a burn by recording

the mass gain of filters.

For burns ignited from a "point" source at the top of the bed,

the smolder propagation speed is almost independent of the

superficial gas velocity U at an average value of 0.057 mm/s for air

velocities from 1.2 to 2.7 mm/s. The weight percent of cellulose

lost at the completion of the burn increased somewhat with increasing

air velocity; at U = 1.2 mm/s the percent weight loss was 46% whereas

at U = 2.7 mm/s the weight loss was 55 to 59%.

For each of these experiments a burst of smoke is detected by

the optical counter upon ignition. The smoke concentration then

rapidly decreases. Later, the smoke concentration is observed to

increase with time reaching a maximum concentration approximately 25

to 35 minutes after ignition. Thereafter, the smoke concentration

decreases almost experimentally with time, but there is usually at

least one subsequent time for each run when the smoke concentration

increases abruptly. Following the abrupt increase, the smoke

concentration again decreases exponentially with time with

approximately the same slope as before the abrupt increase. We

believe the abrupt increases coincide with sudden changes of the bed

structure due to slumping and opening of fissures. Post burn

examination of these beds showed that each bed developed a conical

crater with fissures. These structural defects were more pronounced

the higher the air velocity.

The slopes of the logarithm of concentration versus time for the

decreasing concentration regime was determined for each particle size

range of the optical counter where significant counts were

recorded. An example is Figure 1 for the bum at U = 2.0 mm/s. The

slope shows a minimum for particle diameter Dp of about 0.7 ym. The

form of this curve is consistent with particle removal by

filtration. Small particles are efficiently removed by Brownian

diffusion and large particles are efficiently removed by

sedimentation leaving an intermediate size particle less efficiently

captured. Similar plots for the other flow rates showed similar

trends with a more pronounced minimum at U = 2.7 mm/s and a less

pronounced minimum at U = 1.2 mm/s. In general, for a given particle

size, the slope decreases with increasing gas velocity. This is

consistent with the two collection mechanisms postulated because of

the decreased residence time within the bed with increasing gas

velocity.

For top ignited burns, we fitted the formula c = c

Q

t n for the

concentration c of particle of a given size as a function of elapsed

time t from ignition for the regime where the concentration increases

with time. For the most part, values of n were independent of

particle size although significant scatter was found especially at

the highest gas velocity. The weak dependence of n on Dp suggests

103
that early in a top ignited burn very little filtration of the smoke

produced occurs because of the short distance the smoke needs to

travel to reach the top of the bed. Apparently, the concentration

increases because the volume undergoing smoldering increases. We

found the exponent decreases with increasing gas velocity. At U 3

1.2 mm/s the exponent n = 2.3; at U = 2 mm/s the exponent n = 1.2;

and at U *» 2.7 mm/s the exponent is between 0.4 and 1.

We have filtered the smoke passing up the chimney to determine

the time dependence of the mass of smoke emitted. The filters were changed at twelve minute increments during the course of the burn.

Figure 2 shows the time history of the mass concentration of aerosol

computed from the weight gains on the filters after drying by

exposure to a flow of dry air at 2£pm for 10 minutes. Superimposed

on this graph is the mass concentration induced by the Royco optical

counter integrated for the corresponding time periods, corrected for

dilution, and assuming the particle density ^.s 1 g/cm . There is

good correspondence between these two measurements when the mass gain

is above our level of resolution of 2 mg. We have improved our technique and believe we can achieve a resolution of 0.2 mg.

A plot of the weight gain of each filter determined immediately

upon removal from the experiment versus the weight gain after drying

is found to be very nearly a straight line. If we assume that the mass of water on each filter is the same because each filter is

exposed to 100% humid air produced in the bum and if we assume that

there is a constant fraction f nv

of non-volatile organics .in the

organics produced as smoke, then we can derive the following formula:

^immediate

= ^^nv^ ^dry + Wwater

The measured slopes give a range of f QV from 0.4 to 0.6 for the

several burns which have employed filters.

Considerate effort was spent in calibrating the Royco aerosol

counter and in developing a sampling and dilution probe to be

delivered to the NBS for it’s in house smoke research.

The information to be obtained on time dependent rates of

production, size distributions and other properties of smoke aerosols

emitted from smoldering porous fuels is important for improved fire

detection and smoke hazard assessment. A significant fraction of

fire related deaths, injuries and property losses are due to fires

that originate as slow smoldering combustion of porous fuels. Early

and reliable detection of smolder generated smoke could reduce these

losses by enabling automated countermeasures. This research also is

important for the development of models for estimation of fire

hazards. Smoke reduces visibility, making evacuation or rescue more difficult. Inhaled smoke may have a debilitating effect by inducing

choking and a long term health effect as a carrier of toxic

chemicals. Smoke also alters the development of fire by modifying

104
the heat transfer through radiation. Smoke is a reservoir of highly

combustible fuel and is important in flashover. All of the effects

depend on both the quantity and size of the smoke aerosol. Any

modeling of the smoke aerosol in the air spaces must have information

on the source term.

RO 11333ft DP (JJM)

Jo* a

Vi} . h ‘P

(**!•** J

105
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : University of California, Berkeley

Grant No

.

: NB80NADA1064

Grant Title : Fire Propagation in Concurrent Flows

Principle Investigator : Professor A.C. Femandez-Pello

Department of Mechanical Engineering

University of California

Berkeley, CA. 94720

Other Professional Personnel : C.-P. Mao, Ph.D. Candidate

H.-T. Loh, Ph.D. Candidate

NBS Scientific Officer: W.J. Parker

Technical Abstract

A study is being performed of the process of fire spread in gaseous

flows moving in the direction of flame propagation, i.e.: concurrent or flow assisted flame spread. This mode of fire spread is very rapid and

hazardous, and consequently of great interest in the fire safety field.

The study includes two research efforts: 1) Natural convection, flow

assisted, flame spread over enclosure's walls; 2) Flame spread over a flat

surface in a concurrent forced flow. During this reporting period, a numerical analysis has been performed of the natural convection, steady

burning of combustible surfaces of varied length and composition forming

the walls of an enclosure. The analysis represents an intermediate step

toward the development of a theoretical model of the spread of fire in

enclosures. The results for the location and length of the flame agree

well with experimental data. Measurements of the rate of flame spread in

a concurrent forced flow of varied velocity and oxygen concentration show

that the spread process is controlled primarily by heat transfer from the

flame to' the fuel. The measured rate of spread of the pyrolysis front,

V , can be correlated in terms of the free stream gas velocity u , and

^ 2 mass transfer number B, by using an expression of the form V^/B 'v u^,

which agrees with the predictions of thermal theories of the flow assisted mode of flame spread.

Steady, Free Convective Burning of Surfaces in Enclosures :

A numerical analysis of the steady, laminar, non-radiative burning

of surfaces in a partial enclosure has been completed during this period.

To perform the analysis, a computer code to solve the two-dimensional,

elliptic, buoyant, laminar, non-reactive conservation equations was modified to include the vaporization of a surface and the flame sheet com- bustion of the pyrolyzed fuel. Theoretical predictions of the velocity

106
and temperature fields, and of flame contours were obtained for fires in

enclosures of varied soffit and pyrolyzing lengths, and with PMMA or POM

as combustible materials.

A representative example of the results obtained in this work is

presented in Figs. 1 and 2. The figures show the characteristics of the

predicted velocity and temperature fields in a compartment fire and the

comparison of the flow structures for fires generated by PMMA or POM

burning. In Figs, la and lb the predicted flow velocity and temperature

profiles are presented for a PMMA compartment fire with a pyrolyzing

length of 7 cm and in Figs. 2a and 2b the corresponding distributions

are presented for a POM compartment fire with the same pyrolyzing length.

Comparison of Figs, la and 2a show that the flow structures are quite

similar for both cases. However, for POM the two vortices in the center

region of the compartment are stronger than those predicted for PMMA.

The top vortex tends to roll the flame backwards so that the tip of the

flame does not emerge through the compartment opening as occurs with PMMA.

For POM fire, the flame size is smaller than for the PMMA fire suggesting

that POM is a less hazardous material than PMMA. The results of this

work have been reported in a paper entitled "An Investigation of Steady

Wall-Ceiling and Partial Enclosure Fires". To be published in the J. of

Heat Transfer.

Fire Spread in a Concurrent Forced Flow :

Measurements are currently underway of the rate of flame spread over PMMA sheets in a forced flow of varied velocity and oxygen .concentration

moving in the direction of flame propagation. The experimental installation consists of a small scale combustion tunnel and its complementary

instrumentation. The test section of the tunnel is 61 cm long and has a rectangular cross section 12.7 cm by 7.6 cm. It is made of Marinite and

has Pyrex windows to permit optical access to the experiment. The sheet

of PMMA is embedded flux in the Marinite and placed at the entrance of

the test section so that a flat plate flow is developed. The gaseous

flow consists of a mixture of 0

^ and ^ which flow rates are previously

metered with critical nozzles. The flow velocity is currently being

measured with a pitot tube until a LDV system is made operational.

Surface temperature histories provided by thermocouples embedded at fixed

distances along the PMMA surface are used to calculate the rate of spread

from the time lapse of pyrolysis arrival to consecutive thermocouples and

the known distance between thermocouples.

The results of the measurements of the rate of spread of the pyrolysis front over PMMA sheets 1.25 cm thick as a function of the flow ve- locity are shown in Fig. 3 for several oxygen mass fractions of the gas

flow. It is observed that for all oxygen concentrations tested, the

spread rate is linearly proportional to the flow velocity with the slope

increasing with the oxygen concentration. In Fig. 4 the data of Fig. 3

2 are correlated using V /B as ordinate and u as abcissa. V is the

P

00 P spread rate, B is the mass transfer number and u the free stream CO 107
velocity. The correlation is suggested by present thermal models of the

flow assisted mode of flame spread. It is seen that the experimental

results correlate quite well, indicating that thermal models can describe

correctly the mechanisms controlling the flame spreading process. It is

believed that the observed scatter in the correlation of the data is due

to flame length effects not included in the correlating parameters.

Mixed Convective Burning of Surfaces with Arbitrary Inclination :

An analysis has been developed for the mixed, forced and free, con- vective combustion on a flat fuel surface of arbitrary inclination. A

1/ 2n

mixed-convection parameter (Re, + Gr ) which properly scales the

X X

dependent and independent variable fields and a mixed convection ratio

n 1/2

(Grxx' /Re ) which plavs the role of the downstream local similaritv

coordinate are introduced in the nondimensionalization of the equations.

It is shown that these two parameters, rather than the standard Reynolds,

Re , and Grashof, Gr , numbers are the optimum choice of governing nonX X

dimensional groups for this problem. The values of m and n are selected

to obtain a similarity solution of the governing equations for the limiting cases of pure forced and pure free convection. This occurs at the

particular cases of a vertical (m = 2, n = 4) and a horizontal (m = 2, n = 5) surface, which are the cases that have been solved in this work.

With this formulation, the solution of the problem provides for both

cases smooth transition of all physical variables from one convective

limit to the other. Results obtained from numerical integration of the

governing equations and from application of the local similarity approximation show that the range of validity of local similarity is extended

beyond that obtained with alternate formulations and that the proper

limits are approached.

Reports and Papers

Fernandez-Pello, A.C. and Hirano, T., "Controlling Mechanisms of Flame

Spread" Published jointly in Fire Science and Technology (Japan) _2, 1,

17-54, 1982 and Combustion Science and Technology, 32_, 1-31, 1983.

Fernandez-Pello , A.C. and Pagni, P.J., "Mixed Convective Burning of a Vertical Fuel Surface" Proceedings of the 1983 ASME-JSME Thermal Engineering Joint Conference, Honolulu, Hawaii, Vol. 4, 295-301, 1983.

Mao, C.-P., Fernandez-Pello, A.C. and Humphrey, J.A.C., "An Investigation

of Steady-Wall Ceiling and Partial Enclosure Fires" J. of Heat Transfer

(in press)

,

1983

.

Mao, C.-P., Fernandez-Pello , A.C. and Pagni, P.J., "Mixed Convective

Burning of a Fuel Surface with Arbitrary Inclination" Submitted to the

J. of Heat Transfer, 1983.

108
VERTICAL

WALL

(ml

VERTICAL

WALL

Iml

Fig, la

CEILING (ml 0 0 03 OlO 0 13 020

(b) Fig, lb

CONTOU*

L£VCL3 02

03

a*

03

Oft or

(a)

CEILING (m) 0 0 05 OlO 0 IS 020

CO*r Ou*

l£ vCLS

(0 ) Fig. 2a Fig. 2b

Fig. 3 Fig. 4

109
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : University of California, Berkeley

Grant No. : NB80NADA1072

Grant Title : - Intralaboratory Evaluation of a Standard Room Fire Test

Principal Investigator : Professor Robert Brady Williamson

Department of Civil Engineering

University of California, Berkeley

Berkeley, California 94720 ,(415) 642-5308

Other Professional Personnel : Fred L. Fisher, Development Engineer

Fred Mowrer, Associate Specialist

NBS Scientific Officer: William J. Parker

Technical Abstract :

The characterization and regulation of the fire growth characteristics of interior finish materials have been of concern for many

years. Since the early 1970's it has been recognized that small scale

test methods are unable to accurately predict the fire growth potential of certain types of interior finish materials, particularly those

composed of synthetic polymers. This recognition has led to an interest in the use of full scale room fire tests for this purpose.

In November 1982 a Room Fire Test Method was published, for

information only, in Part 18 of the ASTM Book of Standards 1

. This

proposed test method appears very promising as a means of providing a realistic assessment of the fire growth characteristics of interior

finish materials in their end-use configuration. This experimental

program has been one of the primary sources of information for the

ASTM Task Group which produced the method as published. Until a series of smaller, less expensive fire tests, can be developed and

validated, it is likely that the Room Fire Test Method will be one of

the primary test method for evaluating the fire growth characteristics

of interior finish materials.

The Room Fire Test is now standardized to a test compartment

which is 2.4m (8 ft) wide, 3.7m (12 ft ) long, and 2.4m (8 ft ) from

floor to ceiling. The ignition source is a propane- fired sand burner

placed in one comer of the compartment. The test is conducted by

igniting the burner and measuring the following data: temperature 100

mm (4 in. ) below the ceiling, the rate of heat release (RHR) by

oxygen depletion in the stack, the heat flux to the floor and the

light transmission through the smoke in the stack. Once the test

compartment has been constructed and the instrumentation has been

calibrated, the test is only slightly more difficult to conduct than

no-
other standard fire tests, such as ASTM El 19

The results of room calibration experiments and of experiments

in which the room was lined with 6 mm thick plywood at relatively low

moisture content were presented in in the previous summary and an NBS

GCR Report^. This year additional experiments were conducted using 6

mm thick plywood at higher equilibrium moisture contents (18% and 24%) as well as experiments using 6 mm thick pressure treated fire retardant plywood. In addition, a "screening test" protocol was developed

that may be useful for evaluating prototype materials and conducting

interlaboratory studies with limited amounts of standard materials.

Finally, new experiments with a line burner at the back wall of the

compartment will be briefly described.

The results from four room fire experiments of 6 mm (0.25 in.)

thick A-D Douglas fir plywood are presented below. The. experiments

provide a comparison of the fire behavior of 6 mm thick plywood in an untreated, high equilibrium moisture content (EMC) state (experiments

C-215 and C-216) versus pressure treated fire retardant wood (experiments C-219 and C-220). Experiments C-215 and C-219 provide this

comparison for the case in which the ceiling is covered with plywood

and the walls with gypsum wallboard. Experiments C-216 and C-220

provide the comparison when both the ceiling and walls are covered

with plywood. Table I provides a summary of the plywood treatment and

location within the room for each of the experiments.

TABLE I: Materials Used as Interior Finish for

the Room Fire Experiments

Experiment

’ Interior Finish Material

Number Walls Ceiling

C-202 13 mm Gypsum Wallboard 6 mm Plywood @ 10% EMC

C-212 6 mm Plywood @ 10% EMC 13 mm Gypsum Wallboard

C-213 6 mm Plywood @ 10% EMC 6 mm Plywood @ 10% EMC

C-215 13 mm Gypsum Wallboard 6 mm Plywood @ 18% EMC

C-216 6 mm Plywood @ 24% EMC 6 mm Plywood @ 24% EMC

C-219 13 mm Gypsum Wallboard 6 mm Plywood-Fire Retardant Treated @ 9.1% EMC

C-220 6 mm Plywood-Fire Retar-

: dant Treated @ 11.3% EMC

6 mm Plywood-Fire Retardand Treated @ 11.3% EMC

111
In the proposed test method the following three criteria are associated with "flashover": (1) an average ceiling temperature above

600°, (2) a heat flux of greater, than 20 KW/M^ measured in the center

of the floor, and (3) the first observation of flames out the top of

the door. It is interesting to compare the times at which each of

these criteria is reached in these room fire experiments. A comparison of the flashover criteria is presented in Table II.

TABLE II: Critical Times and Heat Release Rates

for the Room Fire Experiments

rExperiment

Time (MinrSec) to Reach: Approximate t Maximum Rate :

: Number : 600° C.Av.

Ceiling Temp.

20 KW/M*6 Heat Flux at

Floor center

Flames Out

Top of

Door

:of Heat Release

!

:Prior to Flames i

: Out Door (KW) !

: C-202 3:50 M m 4:35 800 :

: C-212 2:55

13KW/M2 §5:23

3:50 3:30 : 950

C-213 1:55 3:25 2:50 950 :

C-215 4:40 M M ^ 8:50 : 750

12KW/M2 §6:30 : C-216 3:20 6:15* 4:48 : 950

C-219

: 590° (§5:00 4.5KW/M2 §4:3(

! 400

C-220 3:35 6:35 5:35 : 800

Cooling water not flowing - time possibly longer.

During experiment C-215 the high moisture content of the plywood

delayed ignition of the ceiling and reduced the rate of flamespread as compared to experiment C-202. However, the additional moisture in the

plywood delayed bumthrough of the ceiling in the corner for a long

enough time to establish burning away from the corner prior to burnthrough of the ceiling above the burner. This ultimately enabled a large enough area of the ceiling to become covered with visible flaming (as observed from the door opening) to cause flashover as defined

by two of the three criteria. The maximum RHR during this experiment

was 1175 kW and it occurred at an elasped time of about 10:00 minutes.

The plywood contribution to the peak rate of heat release was on the

order of 1000 kW.

Experiment C-216, in which both the walls and ceiling were lined

with plywood, indicated a delay in the time to reach flashover of

• 2 approximately 2 minutes as compared to a similar experiment conducted

XU
at 10.1% EMC. The two minute difference can be considered as "drying

time" for the plywood. During this period the burner released on the

order of 19 MJ (18,000 Btu) of energy into the room.

The fire retardant treated plywood ceiling evaluated during ex- periment C-219 did not spread fire away from the corner area above the

ignition source. The RHR produced by the ceiling only was relatively

small. The peak RHR due to combustion of the ceiling was on the order

of 240 kW. The fire did not spread and once the plywood located above

the burner had been consumed, the total RHR decreased to a level only

slightly greater than that produced by the ignition burner. During

experiment C-220 the fire retardant treated plywood walls and ceiling

did lead to flashover of the room. However, flashover was delayed by

approximately 2 minutes, 45 seconds as compared to untreated plywood

at 10% EMC, and 47 seconds as compared to the untreated plywood at 24%

EMC shown in experiment C-216. Another notable difference between the

fire retardant treated and untreated plywood experiments is in their

maximum RHR. In tests of untreated plywood maximum rates of heat

release of about 4 MW were recorded before the test was terminated.

It is probable that these rates of heat release would have greatly

exceeded 4 MW had the experiments not been terminated; however, the

maximum capacity of our experimental facility is only about 4 MW. The

maximum RHR recorded during experiment C-220 was about 3.1 MW, of

which only slightly more than 2.9 MW was the result of plywood combustion. Thus the fire retardant treated plywood indicated two definite

effects; increased time-to- flashover, and a reduced maximum RHR.

References

1. Annual Book of ASTM Standards , Part 18, American Society for Testing and Materials, Philadelphia, PA.

2. Fisher, F.L. and Williamson, R.B., "Intralaboratory Evaluation of a Room Fire Test Method," NBS-GCR-83-42

1

, National Bureau of Standards,

Washington, D.C., January 1983.

Reports and Papers

1. Fisher, F.L. and Williamson, R.B., "Intralaboratory Evaluation of a Room Fire Test Method," NBS-GCR-83-42

1

, National Bureau of Standards,

Washington, D.C., January 1983.

2. Fisher, F.L., Mowrer, F.W., and Williamson, R.B.,"A Room Fire

Screening Test Procedure", Western States Section, Combustion Institute, Paper 83-7 , April, 1983.

113
CENTER FOR FIRE RESEARCH

NATIONAL 3UREAU OF STANDARDS

FY 83

Institution : Lawrence Berkeley Laboratory, University of California,

Berkeley

Grant No

.

: NB 80 NAG-E6839

Grant Title : Fire Modeling

Principal Investigator : Professor Patrick J. Pagni

Mechanical Engineering Department

University of California

Berkeley, California 94720

Telephone: (415) 642-0729

Other Professional Personnel : Clement I. Okoh, Ph.D. Candidate

Valerie J. Lyons, Ph.D. Candidate

Duncan McGehee, M.S. Candidate

James Ang, Ph.D. Candidate

N3S Scientific Officer : Dr. Gary Mallard

Technical Abstract :

The overall goal of this project is to develop physical and mathematical models of the detailed combustion phenomena which control a fire's growth through a structure. These experimental and theoretical

studies will provide bases for code development and for evaluation of

the real fire hazard of materials. This year's report focuses on incorporating experimental results for flame soot volume fractions in radiative combustion modelling [1-4], and on obtaining the variable

fields profiles required for reconstructing the evolution of individual

soot particles in a flame.

An analytical technique has been developed for combined force and

free convection on a flat fuel surface of arbitrary inclination. The

analy/sis uses a laminar boundary layer approximation for the gas flow,

and the flame sheet approximation for gaseous reactions at the flame.

Two new parameters are introduced: m . _ nN l/^.n . , (Gr -r Re ) , a mixed convection

x x parameter which scales the dependent and independent variables, and a

HI n *1 /2 mixed convection ratio, (Gr “7Re. ) /4 which plays the role of a stream-

/L X

wise local similarity coordinate. These two- parameters are shown to be

the optimum choice of governing nondimens ional groups, m and n are chosen to obtain solutions for the limiting cases of horizontal (m = 2, n = 5) , and vertical (m = 2, n = 4) convection. In each case, the new formulation enables a smooth transition of all physical variables solutions from one convective limit to the other. Results have been obtained

114
Fly.

la.

Velocity,

temperature,

upecleu,

and

Moot

profiler

in

an

n-heptane/aii

free

Now

boundary

layer

flame

at

20

mm

from

the

leading

edge.

Kad i

at

Ion

effecta

are

included.

The

calculated

non-adiabatlc

flame

temperature

laT

flume

“

2424

K.

The

perLlnent

dimena

ion

leaa

parametera

are

H

"

5.6,

I)

"

29.0

and

r

0.078.
C s /

uO AX0l

' 'S3lil30T3A

co c\j o CM

Q

• aoJD

<3

Iil/1

GJ <^aidd) aj.

<3 <3

! A

£

£

\JQ

a

Q

O

o

I

•rt

U6

Velocity,

temperature,

species,

and

soot

profiles

as

in

Fig.

la,

except

here

the

distance

from

the

leading

edge

is

100

mm

to

show

the

evolution

of

the

soot

volume

fraction

profile.

The

soot

exists

primarily

in

the

region

between

the

converging

streamline

(v

=

0)

and

the

flame

(Y„

=Y

=

0)

.
by numerical integration of the governing equations, and from a local

similarity approximation. It has been determined that buoyancy is a nonnegligible effect in our horizontal forced flow combustion tunnel, primarily due to elevated Yqoo

. We are now attempting to incorporate radiation in the mixed flow combustion analysis.

In the pure free flow case, the scaling of the physical variables in

real space depends on the reference viscosity, v^, and the profile shapes

depend on the absorption coefficient, K, through the coordinate,

E, = 2^^<x/Gr These properties have been obtained in free flow,

for 5 liquid hydrocarbon fuels, and plexiglass, was obtained by matching flame standoff against analytical predictions at streamwise distances

of x = 2,4, and 10 cm. The absorption coefficient, K, was obtained by

using experimental soot volume fractions adjusted to the optically thin

approximation. These values of < and have been used to calculate the

variable fields shown in figs, la and lb.

It has been possible to measure and quantify carbon particulates in

laminar diffusion flames, and to compute detailed profiles of species and

temnerature, needed for modelling oxidation-formation reactions; as well

as detailed 2-dimensional velocity profiles, enabling the construction

of streamlines in free flow. Upon inclusion of thermophoretic forces and

free-molecular drag and heat transfer, the particle paths may be traced

and the development of each particle analyzed.

Renorts and Papers :

1. R.A. Beier and P.J. Pagni, "Soot Volume Fraction Profiles in Forced

Combusting Boundary Layers," Journal of Heat Transfer, 105, 159-165,

1983.

2. R.A. Beier, C.I. Okoh and P.J. Pagni, "Soot and Radiation in

Combusting Boundary Layers," presented at the 1983 Annual Conference

of the Center for Fire Research honoring Professor Howard W. Emmons.

3. A.C. Fernandez-Pello and P.J. Pagni, "Mixed Convective Burning of a Vertical Fuel Surface," Japan Society of Mechanical Engineers - American Society of Mechanical Engineers Joint Thermal Engineering

Conference Proceedings, _4, 295-301, (1983).

4. C.-P. Mao, A.C. Fernandez-Pello and P.J. Pagni, "Mixed Convective

Burning of a Fuel Surface with Arbitrary Orientation," submitted to

the Journal of Heat Transfer.

117
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution: Lawrence Berkeley Laboratory, University of California,

Berkeley

Grant No . : GE 1653-3

Grant Title: Flame Radiation

Principle Investigator : Professor Chang-Lin Tien

Mechanical Engineering Department

University of California

Berkeley, California 9^720

Telephone: (Ul5) 6^2-0877

Other Professional Personnel : M.A. Brosmer (Ph.D. student)

K.Y. Lee (Ph.D. student)

NBS Scientific Officer : Dr. Takashi Kashivagi

Technical Abstract :

The current objective of this project is to establish a simple

physical framework for the calculation of radiation from complex fire

phenomena. The basic research approach aims at developing approximate

formulations by systemaoic experimentation and analysis of the fundamental aspects of the problem. The present research is focused on two

primary topics: l) Experimental and theoretical determination of

radiative properties of gases evolved from burning condensed fuels

,

principally PMMA, and 2) Development of a simple calculation scheme for

radiation absorption in a thin non-isothermal layer composed of these

gases

.

Radiation of Gases Evolved from Condensed Fuels . A significant

energy input is required to ignite and maintain continuous burning of

a condensed fuel. It has been found that this energy is primarily

transported to the fuel by means of thermal radiation from the flame

zone. As a result of the heading process, numerous gas species evolve

from the solid fuel and act as strong absorbers to the incoming

radiation. These gases therefore strongly influence the ignition and

burning process. The gases of interest are principally complex hydrocarbons of which very little is known concerning the thermal radiation

characteristics. A combined analytic and experimental research effort

is therefore being directed toward the determination of the infrared

radiation characteristics of the evolved gases. The experimental phase

consists of the determination of the spectral absorption of several

hydrocarbons commonly evolved from condensed fuels. These gases in118
elude methyl methacrylate (C^-HgO^), propane (CgHg), propylene (CgHg),

ethane (C^Hg), ethylene (C^H^) , acetylene (C^H^), and methane (CH^).

Infrared measurements are being made for 1 atm. pressure and a temperature range of 300 to 900°K. Typical absorption curves obtained in

this research for propylene (CgHg) are shown in Figs. 1. and 2 for a spectral range of 1200 to 4800 cm"'

1' (8.33 to 2.0 yin). The figures indicate the overlapping nature of the various absorption bands. The

analytic portion of this project is then to develop a simple modeling

scheme to specify the absorption of the overlapping bands and determine

the overall radiation characteristics for the entire infrared region.

A preliminary model has been developed which successfully groups the

primary infrared bands of H^O and 00^ and accurately predicts the

radiation behavior. It will be applied to the complex hydrocarbon data

in an effort to describe the infrared radiation characteristics of the

gases.

Radiative Energy Absorption in a Non-Isothermal Layer . Based on

the information gained for the radiation properties of the hydrocarbon

gases, a simple calculation scheme is being developed for radiation

absorption in thin non-isothermal layers of these gases . The analytic

study involves two steps. First, the gas properties for non-isothermal

conditions will be determined by generalizing the existing methods for

total band absorptance of non-isothermal gas layers to account for the

overlapping bands of the various hydrocarbons. The combined band model

previously mentioned can then be extended for non-isothermal conditions. The second phase then focuses on the calculation of the

radiative energy absorption in the layers based on the equation of

radiative transfer with radiative properties of non-isothermal gas

mixtures. The net result will be to provide fundamental information

to and complement the existing radiation measurements and radiation

modeling for large pool fires.

Reports and Papers :

1. C.L. Tien and S.C. Lee, ’’Flame Radiation," Progress in Energy and

Combustion Science, 8_, Ul-59 (1982).

2. S.C. Lee and C.L. Tien, "Effect of Soot Shape on Soot Radiation,"

J. Quantitative Soectroscopy and Radiative Transfer, 29, 259-265

(1983).

119
ABSORPTIVITY

h

ABSORPTIVITY

Spectral absorption of Propylene near the Vj (IU73 cm” ) and V£ (1651 cm“l) fundamental bands and the 2v^p

(1825 cm“l) first overtone band.

WAVE NUMBER (cm'

1 ) Fig. 2 : Spectral absorption of Propylene near the combined V4,

V3, \>2, and fundamental bands (2950 cm

-"1

) and^the

tvo combination bands of and v^

+

. (4300 cm”-).

120
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution: University of Florida

Grant Number: NB8 1NADA2057

Title: Network Models of Building Evacuation:

Development of Software System - Year Two

Principal Investigators: Thomas M. Kisko and Richard L. Francis, Ph.D.

Industrial and Systems Engineering

University of Florida

Gainesville, FL 32611

NBS Scientific Officer: Leonard Cooper, Ph.D.

Technical Abstract:

This report summarizes the efforts of a two year project to

develop user friendly software for the network modeling of building

evacuation.

When the evacuation of a building involves the flow of people

through well defined passageways, it is natural to consider the

evacuation problem to be a network flow problem. EVACNET+ is a user

friendly interactive computer program that accepts a user defined

network model of a building, converts that model to a time expanded

dynamic "transshipment" network, and solves the dynamic network using

a capacitated minimum cost network flow algorithm. The solved

dynamic network gives a time-dependent plan to evacuate the building

in a minimum time, and identifies building evacuation bottlenecks.

The first year's effort of the project involved the development

of the interactive computer program called EVACNET+. The second

year's effort involved coding a post-processing routine, implementing

and testing EVACNET+ on several types of computers, writing a user's

guide, and testing the system with a sample of potential users.

The user defined network representation of a building is called

a static model. A static model consists of a set of static nodes

connected by static arcs . The nodes represent building components

such as rooms, halls, landings, stairs and lobbies. The arcs represent the passageways between the building components. Nodes

have two attributes: capacity and initial contents. The attributes

of arcs are traversal time and capacity per unit time.

A static model is constructed by relating the building

components and passageways of a building to nodes and arcs of a static model. The attributes of the nodes and arcs are estimated by

121
utilizing the dimensions of the building and the distribution of

people in the building at the time of the evacuation.

When the EVACNET+ is run, the static model is converted to a time expanded network called a dynamic model. A dynamic model is a representation of the building where each node of the static model is

expanded into a series of dynamic nodes. Each dynamic node represents

a building component at the end of a time period. Dynamic nodes

associated with a specific static node are connected with hold-over

arcs . The hold-over arc flows represent people staying in a room for

the unit time period associated with the specific hold-over arc.

The dynamic nodes are also interconnected by movement arcs. Flows in these arcs represent, for a specific time period, the movement of people from one building component to another building component. There are a series of movement arcs for each individual static

arc. Movement arcs proceed from a dynamic node at one time period

and to a dynamic node for a later time period; the later period is

determined by the traversal time of the associated static arc.

The dynamic model is solved using NETFLO as a subroutine to

EVACNET+. NETFLO is a primal network code for the solution of capacitated network flow problems. The principal limitations of the model

are as follows: (1) it is a linear model; (2) it does not represent

behavioral aspects.

EVACNET+ is an interactive computer package that is user

friendly. The input is free format. Static nodes and arcs are referred to using a special form. For example, WP2.3, refers to the

second workplace on the third floor. WP2.3-HA4.3 refers to a static

arc from the workplace to a hall on the same floor.

A user running EVACNET+ sits at a computer terminal and first

enters the static nodes and arcs representing the building of

interest. The process is totally "menu driven", in the sense that

all the user has to do is select options and answer associated questions. The model is also run interactively. Results can be

displayed on a terminal or printed. If the user wishes, the static

model may be modified and rerun.

Figure 1 is the master option list of EVACNET+. When the option

list is displayed, the user has twelve alternatives to select from.

Upon entering a valid option code, the system will display a suboption list. From the suboption list the user may select any of the

desired actions presented, including returning to the master option

list.

122
EVACNET+

BUILDING EVACUATION ANALYSIS PROGRAM

MASTER OPTION LIST

CODE REQUESTED ACTION

EN - ENTER NODE DEFINITIONS

EA - ENTER ARC DEFINITIONS

LN - LIST NODES

LA - LIST ARCS

DN - DELETE NODES

DA - DELETE ARCS

SYS - DEFINE OR REDEFINE SYSTEM ATTRIBUTES

RM - RETRIEVE DEFINED MODEL

RUN - RUN MODEL

EXAM - EXAMINE RESULTS

QUIT - TERMINATE EXECUTION OF EVACNET

HELP - WHENEVER YOU HAVE QUESTIONS

ENTER CODE OF REQUESTED ACTION

FIGURE 1 - EVACNET+ MASTER OPTION LIST

Figure 2 is an example of a suboption list. It is the option

list produced by the EXAM master option and allows the user to select

any of 14 specific results.

EVACNET+ is a powerful tool that will allow fire safety

engineers to make objective decisions about the evacuability of

buildings

.

REPORTS AND PAPERS:

Chalmet, L. G. , Francis, R. L. , and Saunders, P. B., "Network

Models For Building Evacuation", Management Science, Vol. 28, No. 1,

pp. 86-105, January, 1982.

Also reprinted in Fire Technology , Vol. 18, No. 1, pp. 90-113,

February, 1982.

Kisko, T. M. , and Francis, R. L. , "Network Models of Building

Evacuation: Development of Software System", Final Report - Year

One, National 3ureau of Standards, NB81NADA2057 , December, 1982.

123
Kisko, T. M. , and Francis, R. L. , "EVACNET+: A Network Model of

Building Evacuation", Proceedings of the Conference on Computer

Simulation in Emergency Planning, San Diego, January, 1983.

Kisko, T. M. , "EVACNET+ Implementation Guide", Industrial and

Systems Engineering Department, University of Florida, Gainesville,

FL, August, 1983.

Kisko, T. M. , and Francis, R. L. , "EVACNET+ User's Guide",

Industrial and Systems Engineering Department, University of Florida,

Gainesville, FL, August, 1983.

PRIMARY EXAM OPTION LIST

FORM MODEL ID - "EXAMPLE THREE STORY BUILDING"

1 SUMMARY OF RESULTS:

BASIC STATISTICS OF EVACUATION

2 DESTINATION ALLOCATION:

NUMBER OF EVACUEES BY DESTINATION

3 TOTAL ARC MOVEMENT:

TOTAL MOVEMENT THROUGH AN ARC BY ARC

4 BOTTLENECKS

:

IDENTIFICATION OF BOTTLENECK ARCS

5 FLOOR CLEARING TIME:

TIME TO CLEAR A FLOOR BY FLOOR NUMBER

6 UNCONGESTED TIMES:

UNCONGESTED EVACUATION TIME BY NODE

7 NODE CLEARING TIME:

TIME TO CLEAR A NODE BY NODE

8 BUILDING EVACUATION PROFILE:

NUMBER OF EVACUEES BY TIME PERIOD

9 DESTINATION EVACUATION PROFILE:

NUMBER OF EVACUEES BY TIME PERIOD FOR EACH DESTINATION

10 NODE CONTENTS PROFILE:

PEOPLE WAITING AT END OF TIME PERIOD BY TIME PERIOD

11 NODE CONTENTS SNAPSHOT:

PEOPLE WAITING AT END OF THE PERIOD BY NODE

12 ARC MOVEMENT PROFILE:

MOVEMENT THROUGH AN ARC BY TIME PERIOD

13 BOTTLENECK PROFILE:

BOTTLENECK ARC INFORMATION BY TIME PERIOD

14 NON-EVACUEE ALLOCATION:

NUMBER OF NON-EVACUEES BY NODE

ENTER OPTION NUMBER, OR 'END' TO RETURN TO MAIN MENU

FIGURE 2 - EVACNET+ EXAM OPTION LIST

124
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : University of Maryland, College Park

Grant No

.

: NB80NADA1067

Grant Title : The Determination of Behavior Response Patterns in Fire

Situations, Project People II

Principal Investigator : Dr. John L. Bryan, Professor and Chairman

Department of Fire Protection Engineering

University of Maryland

College Park, MD 20742

(301) 454-2424

Other Professional Personnel : Mr. James A. Milke, Lecturer

NBS Scientific Officer : Dr. Bernard Levin

Technical Abstract

The progress involved in the final phase of this study involved

the analysis of the behavior response patterns identified from indepth, open-ended interviews with supplemental structured questionnaires. The study interviews were conducted by University. of Maryland

personnel at the scene of the fire incident in the time period from

one to four weeks following the occurrence of the fire incident.

The objectives of this research study were established in the

initial phase of the study, and were continued during the final phase

of the study with the emphasis during this reporting period on objectives 2 and 3:

1. To analyze the established variables of building occupants

in fire situations as these variables have been established

and identified in the previous project people studies primarily concerned with the residential occupancies and the

project people II studies primarily concerned with the

health care occupancies.

2. To attempt the evaluation of the existing models of human

behavior in these fire incidents. The premodel concepts

of Archea and Withey were analyzed with the models of

Bickman, Edelman, and McDaniel. The computer models of Stahl

and the model of Berlin were evaluated with the conceptual

models of Canter.

125
3. To compare the developed human behavior response patterns to

the provisions of the Life Safety Code and the model building codes.

The research study has evaluated the preconceptual models, the

conceptual models and the computer models of human behavior response

with the observed and documented behavior response patterns established from the study populations of both the Project People and the

Project People II research studies. The Project People study involved

335 fire incidents with questionnaire responses from 584 individuals.

The Project People II study involved 65 fire incidents confined to

health care, educational, correctional and large residential occu- pancies with a total questionnaire and interview population of 380

individuals. Thus, the total study population utilized in the analysis

was obtained from a total of 400 fire incidents and 1,464 individual

behavioral response patterns.

The established and analyzed human behavioral response patterns

were compared with the provisions in the 1981 edition of the Life

Safety Code, the 1981 edition of the Basic Building Code, the 1982

edition of the Uniform Building Code and the 1979 edition of the

Standard Building Code. The behavior response patterns indicated

few of the participants observed exit signs, varying between 6 and 8

per cent. The participants tended to move through smoke to obtain

egress, and the behavior in the majority of the fire incidents would

be classified as information seeking and objective orientated in

contrast to the sterotyped accounts of individuals panicking and

competing for escape. Altrustic behavior was frequent, involving

the notification of others, assistance to others, and reentry of the

fire incident building to assist others.

The features of the codes that would appear to require further

study from the analysis of the behavior response patterns involved;

the color, location and design of exit signs; the utilization of

audible signaling devices rather than verbal communicative devices

for evacuation notification; and the provision of the floor level

illumination specified in the codes at the floor level.

The most effective and productive behavioral responses in the

health care occupancies involved the closing of patient room doors

by staff personnel. Staff personnel in health care occupancies

were alerted to the fire incidents by the automatic closing of smoke

barrier doors in addition to the conventional signaling devices.

126
Reports and Papers

Bryan, John L. , Implications for Codes and Behavior Models From The

Analysis of Behavior Response Patterns in Fire Situations as Selected From The Project People and Project People II Study

Programs . NBS GCR-83-425, March 1983.

127
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

Institution:

Grant No .

The University of Michigan

NBS Grant NB80NADA1054

Grant Title: Degradation of Mechanical Properties of Wood During

Fire

Principal Investigator :

Other Professional Personnel:

Professor George S. Springer

Department of Mechanical Engineering

and Applied Mechanics

The University of Michigan

Ann Arbor, Michigan 48109

-M.H. Do

N.H. Jin

C.H. Tsai

NBS Scientific Officer: William J. Parker

Technical Abstract :

The objectives of this investigation were to evaluate the de- crease in mechanical properties of wood exposed to fire, and to

develop a method that can be used to predict the failure time of

loaded structural members during fire exposure. In order to achieve

these objectives, tests were performed measuring the thermal response

as well as changes in the mechanical properties of wood exposed to

flames or to a radiant heat source. In conjunction with the test,

models were developed for describing the behavior of the wood ex- posed to high temperature environments and for predicting the failure

time.

An important part of the pyrolysis of wood is the heating up of

wood and the evaporation of volatiles from the material. The heating

up is characterized by a temperature rise inside the material. The

evaporation of volatiles is represented by a mass loss. In this

investigation the temperature response and mass loss of wood were measured at heat fluxes which result in surface temperatures of 100

to 800°C. Data were obtained for southern pine and douglas fir.

These types of wood were selected for the tests because of their

wide use in the building industry. The measurements were performed

by placing 100 mm long and 25.4 mm wide test specimens in a temperature controlled oven. The weight (mass) losses of the specimens

and the centerline temperatures were recorded as a function of time.

The oven temperatures were 100, 160, 245, 400, 600, and 800 °C.

Specimens of different thicknesses were used in the tests, the thick- nesses being 6.35, 12.7, 19.05, and 25.4 mm. The weight loss and

the thermocouple data were compared to the results of the analytical

128
model described subsequently. Good agreement was found between the

data and the results of the model.

Tests were- also performed to assess the influence of the ambient

oxygen concentration on the mass loss. In these tests the oven was filled with either pure oxygen or with pure nitrogen. Mass losses

were measured in these two environments at 100 and 245 °C. The mass

loss was somewhat higher in the pure oxygen environment. However,

the maximum difference in the mass loss in pure oxygen and in pure

nitrogen environments was only about 25 percent.

The tensile, compressive, and shear properties of southern pine

and douglas fir were also measured after the test specimens were

heated at either 100, 160, 245, 400, 600, or 800°C for different

lengths of time. The strengths and the moduli in the directions both

parallel and transverse to the grain were then measured at room temperature. The longitudinal and the transverse tensile strengths and

moduli of southern pine and douglas fir were measured as functions

of exposure time at all six of these temperatures. In addition, the

longitudinal and transverse compression, and the longitudinal shear

strengths and moduli of southern pine were measured at 400, 600 and

800°C. Specimens with different dimensions were used in the tests.

Thus, the data provide the longitudinal and transverse strengths and

moduli as functions of specimen geometry, exposure temperature, and

exposure time. It is noted that longitudinal tensile strengths of

southern pine were also measured with specimens kept at elevated

temperatures during the tests. The strengths of the specimens tested

"hot" and "cold" agreed closely.

The strengths and the moduli were also calculated by the model

described below. The results of the model and the data agree well,

creating confidence in the validity of the model.

In addition to testing, analytical models were developed to

simulate the response of wood to fire exposure. The major goals in

constructing the models were to describe changes in the thermal and

mechanical properties and, most importantly, to predict the time of

failure. The model was developed in three steps: a) calculation

of the temperature distribution and the mass loss, b) prediction of

the changes in the tensile, compressive, and shear properties, and

c) prediction of the failure time.

In the first part of the model the temperature distribution inside the wood and the mass loss are calculated. This part of the

model is based on the law of conservation of energy, with the chemical

reactions being represented by a single step Arrhenius bulk reaction.

As noted above, the results of the model agreed well with the data

generated in this study.

The second part of the model is used to estimate changes in the

strengths and the moduli. This part of the model is based on the

129
hypothesis that degradation in the mechanical properties is related

to the mass loss due to volatilization of the wood. Using the model,

together with data obtained in this program, correlations were developed which show the changes in the tensile, compressive, and shear

strengths and moduli of southern pine and douglas fir in the temperature range 100 to 800 °C. As pointed out above, the strengths and

moduli of southern pine and douglas fir specimens exposed to elevated

temperature predicted by the model were in good agreement with the

data.

The third part of the model provides the failure time of loaded

beams during fire exposure. The model employs the flexure formula

modified to account for changes in the strength with exposure time.

In addition to the failure time, the model also yields the changes in

the safety factor with time before failure occurs.

On the basis of the model, a "user friendly" computer code was developed. All three steps of the model are incorporated into this

code. The computer code can be applied to loaded wooden beams ex- posed to elevated temperature and provides the following parameters

as functions of exposure time: a) temperature distribution inside

the wood, b) mass loss, c) longitudinal and transverse tensile

strength and modulus, d) longitudinal and transverse compressive

strength and modulus, e) longitudinal shear strength and modulus,

f) safety factor, and g) failure time.

Failure times calculated by the model were compared a) to

failure times (measured in this study) of 19 x 19 mm and 1200 mm long

simply supported southern pine beams exposed to fire, and b) to

failure times (measured by NBS) of southern pine ceiling joists

during the fire of a full scale room. Reasonable agreements were

found between the calculated failure times and the data.

The results of this investigation provide a means for estimating

the failure time of loaded wooden beams during fire. This information can be utilized in designing wooden structural members so as to

minimize losses resulting from failure.

Reports and Papers

G.S. Springer, and M.H. Do, "Degradation of Mechanical Properties of

Wood During Fire". Report submitted to Center for Fire Research,

National Bureau of Standards, May 1983.

R.M. Dastin, D. A. Stanke, and G.S. Springer, "Mechanical Properties

of Southern Pine and Douglas Fir at Elevated Temperatures" Journal

of Fire and Flammability , (in print)

.

M.H. Do and G.S. Springer, "Mass Loss of and Temperature Distribution

in Southern Pine and Douglas Fir in the Range 100 to 800°C" Journal

of Fire Sciences (submitted)

.

130
M.H. Do and G.S. Springer "Model for Predicting Changes in the Strengths

and Moduli of Wood Exposed to Elevated Temperatures", Journal of Fire

Sciences (submitted)

.

M.H. Do and G.S. Springer, "Failure Time of Loaded Wooden Beams during

Fire", Journal of Fire Sciences (submitted).

131
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution ; University of Montana, Missoula, MT 59812

Contract Number : NB81NADA2066

Grant Title : Chemistry of Smoldering Combustion and its Control

Principal Investigator ; Professor Fred Shafizadeh

Wood Chemistry Laboratory

University of Montana

Missoula, MT 59812

(406) 243-6212

Other Professional Personnel ; Dr. Yuki Sekiguchi

NBS Scientific Officer: Dr. Thomas J. Ohlemiller

Technical Abstract

The general objective of this project is to develop a molecular

understanding of smoldering combustion and possible methods for controling it. The present studies are aimed at determining the chemical

changes in composition and structure of the substrate and correlation of

these structures with the reactions involved in smoldering combustion.

It has been shown that smoldering combustion of cellulosic materials involves (a) pyrolysis of the substrate to provide a highly reactive pyrophoric char, (b) chemisorption of oxygen on the fresh char, and

(c) gasification of the char from sites containing chemisorbed oxygen,

resulting in the creation of new active sites and propagation of the

combustion process

.

Heating of cellulosic materials leaves a solid residue , which is

neither intact substrate nor pure carbon, but a different material at

various stages of charring and carbonization. The intermediate chars

are characterized by the functional groups present, including aromatic

and paraffinic structures, a high concentration of free spins trapped in

a rigid structure or stabilized by aromatic structures , a large surface

area, and a high degree of reactivity, all of which depend on progression of the secondary reaction in the solid phase. Development of these

structures and functionalities has been investigated by several chemical and physical methods and related to the pyrolysis conditions, particularly heating, the presence of inorganic catalysts, and the reactivity of the products. These experiments were conducted with cellulose,

lignin and wood heated for 5 min at temperatures ranging from 300-600 °C.

Development of aromaticity was established by permanganate oxidation of chars which gives benzene polycarboxylic acids derived from the

aromatic nuclei, indicating the extent of aromaticity and cross linking

132
of the carbon chain in polycyclic aromatic structures. FTIR was used to

show the disappearance of the hydroxyl and glycosidic group at ~3500 and

900-1200 cm“^- and the formation of C=C and C=0 groups at 1600 and 1700 cm

-

, respectively. Quantitative data on the concentration of various

carbon species was obtained by CP/MAS -^C-NMR. These species included

paraffinic (0-60 ppm), glycosylic (60-110 ppm), aromatic and olefinic

(100-170 ppm) , carboxyl and ester (170-190 ppm) and carbonyl carbons

(190-220 ppm)

.

These data indicated a rapid weight loss at temperatures up to 400°C

which is accompanied by destruction of the anhydroglucose units in cellulose through dehydration, rearrangement and development of C=C , C=0

and COO groups, forming a relatively stable char containing aromatic and

aliphatic groups. The "stable" char formed at 400 °C contained 69% aro- matic, 27% paraffinic and no glycosylic carbons (see Figure 1) . Heating

at higher temperatures resulted in preferential loss of the paraffinic

groups through homolytic cleavage, forming highly condensed polycyclic

aromatic structures and resonance stabilized free radicals. At 500 °C

the char contained 88% aromatic carbon with 12% intermittent paraffinic

groups (see Figure 1) , and nearly a maximum concentration of free spins.

Surprisingly, the lignin and wood chars prepared at 400°C had about

the same aromatic content as the corresponding cellulosic char, although

the char yields were substantially higher from lignin and wood as compared to cellulose. Therefore it was concluded that the presence of preformed aromatic groups (guaiacyl groups) does not increase the aromaticity of the chars from lignin. The char from lignin and wood showed

distinct NMR peaks for the methoxy phenyl groups of lignin (guaiacyl

units) from which the char yield of the lignin component of wood could

be estimated.

DSC and TG studies simulating smoldering combustion of cellulose

and chars prepared at temperatures up to 600 °C showed that the heat re- lease associated with the oxidation reactions takes place in two staqes

corresponding to the rapid weight loss at ~350°C and to combustion of the

stable char at 500 °C. Furthermore the magnitude of the oxidation isotherms was highly dependent on the progress of charring and carbonization of the substrate. As shown in Figure 2, the second isotherm (at

~500 C) is very small for cellulose but gradually expands as the charring reaction proceeds and the aliphatic carbons are converted to polycyclic aromatic carbons. Graphite, which is highly crosslinked behaves

quite differently and does not show either of the two isotherms. It

appears that the first isotherm is caused by oxidation of the more reactive aliphatic component and the second isotherm is due to the oxidation

of the more stable and resistent aromatic groups in the char; thus , the

intermediate chars are more reactive and are oxidized at lower temperatures to provide the driving force for smoldering combustion.

Reports and Papers

W.F. DeGroot and F. Shafizadeh , "Effect of Inorganic Additives on Oxygen

Chemisorption on Cellulosic Chars", Carbon 21, 61-67 (1983)

.

133
F. Shafizadeh and Y. Sekiguchi, "Development of Aromaticity in Cellulosic

Chars", Carbon , in press.

F. Shafizadeh, "The Chemistry of Fire Retardants", Proceedings of the

Conference on Chemical Aspects of Wood Technology by Ingvar Johansson

and Solveig Johansson, Swedish Forest Products Research Laboratory,

Stockholm, Sweden, June (1982).

F. Shafizadeh, "Pyrolytic Reactions and Products of Biomass", Proceedings of the 1983 Fundamentals of Thermochemical Biomass Conversion, an International Conference, Estes Park, Colorado, in press.

F. Shafizadeh, "Chemistry of Pyrolysis and Combustion of Wood", Progress

in Biomass Conversion , 3, 51-76 (1982)

.

t . Sekiguchi, J.S. Frye, and F. Shafizadeh, "Structure and Formation of

Cellulosic Chars", J. Appl . Polym . Sci . , submitted for publication.

F. Shafizadeh, "The Chemistry of Pyrolysis and Fire Retardants", ACS

Advances in Chemistry: The Chemistry of Solid Wood", Roger M. Rowell,

ed; Academic Press

,

submitted for publication.

Char preparation temperature , ®C

Figure 1. Concentration of different carbon species in char prepared

at 325-500°C: qlvcosvlic , -/V ; aromatic, -T"}- ; paraf f inic-T)-;

and carbonyl and carboxyl ,

.

134
Figure 2. Differential scanning calorimetric curves of cellulosic

chars measured in a stream of air. a = cellulose; b-f = cellulosic chars prepared by 5 min heating in N at 340 (b) , 350(c) , 400(d) , 500(e) , and 600°C(f) , respectively;

g - graphite

.

135
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : University of Notre Dame

Contract No .: NBS Grant NB81 NADA 2000

Contract Title : Computer Modeling of Aircraft Cabin Fire Phenomena

Principal Investigators: Professor K. T. Yang

Professor J. R. Lloyd

Professor A. M. Kanury

Department of Aerospace and Mechanical Engrg.

University of Notre Dame

Notre Dame, IN 46556

Other Professional Personnel: H. S. Kou, Ph.D. Candidate

... r . l. McClain, Research Specialist

B. P. De Souza, Ph.D. Candidate

NBS Scientific Officer: Dr. Walter Jones

Technical Abstract

This study of aircraft cabin fire phenomena addresses both the

internal cabin fire problem and the external fuel spill fire-fuselage

interaction problem. The goal of the study is to develop experimentally

verified computer field modeling technology to study the spread of fire

and smoke inside of and external to aircraft cabins which are important

to the description of hazzards to passengers involved in survivable

aircraft fires. The major objectives during the current year are to

develop both experimental and computer based studies of fire fuselage

interactions for externally burning fuel spills and the effects of

distributed ceiling and floor vents on the spread of fire and smoke

inside aircraft cabins. Progress is concentrated in the experimental

studies for the eternal fuselage problem and in calculations of the

effects of blowing from ceiling vents on the fire and smoke spread

inside the cabin. The following is a brief description of the specific

tasks which have been performed.

1. External Pool Fire - Fuselage Interaction Problem

The basic UNDSAFE program has successfully been modified to

accommodate the cylindrical geometry in the neighborhood of the fuselage

of circular cross-section. The calculation mesh is in cylindrical

coordinates close to the fuselage and becomes cartesian far away from

the fuselage. Initial calculations established that the second order

conduction terms were programmed correctly through analysis of the

transient conduction heat up around the fuselage. The debugging process

has been completed for the complete conduction problem by comparing

136
the finite difference calculation, through the cylindrical and cartesian

mesh region, with the exact analytical solution. Of current interest is

the starting up of a pool fire located on the ground beneath the

fuselage. The interactions between the plume and the fuselage are of

current concern.

The companion experimental study is being conducted in the

specially designed wind tunnel. In the experiments air is blown across

a circular cylinder model of the fuselage, of diamter D, which can be

positioned at any height, H, above the floor of the tunnel. Flow

visualization is accomplished through the use of a smoke wire. Figure 1 shows a typical photo with the cylinder located at a dimensionless

height, H/D, of 1.1 and a Reynolds number of 5200 based on the cylinder

diameter. The flow around the cylinder as well as the turbulent

boundary layer flow along the wall are visible. Even at this height

relative to the floor there is indication that there is some interaction

between the cylinder and the floor.. The cylinder was instrumented with

a single pressure tap and the cylinder was made so that it could be

rotated. The pressure on the cylinder as a function of angle around the

cylinder is currently being measured as a function of Reynolds number

and H/D ratio. Shown in Figure 2 are two sets of data for H/D = 0.58

and 0.75. The pressures on the top and bottom surfaces are noted. In

the middle of the tunnel the dimensionless pressure distribution (not

shown) is identical for the top and bottom surfaces. As the cylinder

moves closer to the surface the effect of the wall is to increase the

pressures on the lower surface. The point of the minimum also moves

back around the cylinder in the presence of the wall. These data will

be used for code verification when the corresponding cases are calcul ated.

2. Internal Cabin Fire Control by Venting

Calculations have been made of the internal cabin geometry with

a fire initiated in the central region of the cabin. Fresh air is

injected through the ceiling vents at a velocity of 0.09 m/sec which is

equivalent to a complete air change every 20 minutes. Figure 3 shows an isotherm (a) and a velocity field (b) plot of the cabin environment.

The presence of unsteady behavior is clearly noted in both figures.

Seats are now being added to the flow geometry and radiation effects on the cabin environment are being examined.

Fire hazard is an inherent scenario in survivable accidents for

aircraft, and it is generally recognized that loss of life can be

reduced when fire and smoke spread phenomena are better understood

through careful, systemmatic research.

Reports and Papers

Satoh, K. , Lloyd, J. R., Yang, K. T., Kanury, A. M., "A Numerical

Finite-Difference Study of the Oscillatory Behavior of Vertically Vented

Compartments," Proceedings Second National Symposium on Numerical

Methods in Heat Transfer, 1983, pp. 517-528.

137
Figure 1. Smo!:e wire flow visualization of flow arounc cylinder located 1.1 diameters above the floor.

Re

D =5200

iS

UJX

3

COCO

UJX

X

CO

CO

111

CO2

-1 L

2 I

o

-

o

S

-a

I 1I SYMBOL

O- UPPER SURFACE H/D=0.50_1 - LOWER SURFACE H/D=0.58

O UPPER SURFACE H/D = 0.75

-O LOWER SURFACE H/D-0.75

O

Oo

a

<5 ©: B

& & 0 ^

_ 2 !

! | ! 1 0 30 60 90 120 150 180

ANGLE FROM FRONT OF CYLINDER-DEGREES

Figure 2. Measured pressure distributions around a cylinder near the floor. Re^ = 5200

138
(A)

At Time = 118.38 Seconds (Heat =280 KW)

(B)

MliTfiNC; -Iff

A , >1.049

B , T=1 .099

C , T=1 .148

D , T=1 .197

E , >1.247

F , >1.296

G , >1.345

H , >1.394

I , >1.444

Q , >1.493

At Time = 113.35 Seconds (Heat = 280 KW)

Figure 3. Calculated velocity and temperature distributions

with air injection at ceiling.

139
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Insti tution : University of Notre Dame

Contract Number : NBS Grant NB 81 NADA 2021

Contract Title : Scaling Correlations of Flashover Experiments

Principal Investigator: Professor A. M. Kanury _ Department of Aerospace and Mechanical Engrg.

University of Notre Dame

Notre Dame, IN 46556

Other Professional Personnel: Mr. M. S. Riepenhoff

Graduate Research Assistant

NBS Scientific Officer: Mr. William J. Parker

Technical Abstract

The objective of this project is to develop scaling rules for the room fire flashover problem and to apply these rules to the experimental

data obtained at NBS with the quarter scale model room. The hope

underlying this objective is to discover a correspondence between rooms of different scales and geometries in their flashover behavior. With

such a correspondence in hand, it might become possible to assess from

a set of well -planned experiments if and when flashover would occur in a real room.

Special consideration is given in the present scaling rule

development to the role played by the room dimensions, the lintel

height, wall -linings, the window or door opening geometry and the nature

of the fire source.

Based on mass, momentum, and energy conservation for the fire room,

the following dimensionless parameters are deduced.

. 3/2 Initial fire parameter <j> Q

= ^

v /kWQ

H o

Wal 1 lining parameter g = h(Tf -T )f q/

I

I W

Window geometry parameter \p = W

Q

/H

0

Lintel depth parameter y

= A/W

Q

H o

140
Ceiling heat transfer parameter n = h/kCp

g

Hi/2

[Time to flashover x* = h 2 t*/(KpC)]

mv is the fuel input to the initial fire source. k is a constant

equal to 1.6 kg/sm 5/2 whose origin lies in the mechanics of flow through

the window. W0 and H0 are respectively the window width and height. A

is the area of the celling plus the upper part of the walls lying above

the soffit skirt. h is the convective plus radiative heat transfer

coefficient between the hot fire gases and the ceiling. Cpg is gas

specific heat, t* is flashover time. K, p, and C are respectively the

lining thermal conductivity, density and specific heat. h(Tf-Tw ) is the

heating rate of the wall linings by the growing flames, f is a constant

equal to 0.02 m

2 /kW,the area of walls covered by an initial fire of one kW strength. q is heat release rate (W/m2

) of the wall lining material

exposed to an external flux of I (W/m2

) so that q7T is the measured

average of heat release rate per unit exposure rate.

When the NBS-CFR mobile home flashover fire test data are plotted

with flashover time x* as a function of the initial fire strength <}> and

wall lining combustibility 6 for given n, y and ip, the following con- clusions are apparent.

(a) Data of all the tests for which the flashover time is finite

follow a pattern of decreased x* with increased <j>( 1+8). This pattern is

expectable, for situations involving large initial fires and highly

combustible walls culminate in an early flashover.

(b) There appears to be indication that no flashover would occur

if the initial fire is so small and the wall lining is so noncombustible

as to result in the quantity <j>(l+e) less than about 2.

(

c)

The range of variation in the soffit parameter y, window

aspect ratio ij>, and the ceiling heat transfer parameter a, between the

two sets of full-scale tests and one set of quarter-scale tests, is

quite wide although not systematic. The scatter in the correlation does

not now permit a clear-cut delineation of these parametric effects. The

scatter could be partly due to the incompleteness of the correlation

scheme, partly due to the method of interpretation of the flashover

phenomenon as embodied in the time to flashover recorded in the source reports, partly due to uncontrolled variances between tests which are otherwise deemed identical, partly due to departures in geometric (and,

sometimes, dynamic) similarity between test groups, and lastly due to

possible property variations. Recall that: (i) the wall lining

moisture content is ignored; (ii) the heat release rate of the lining

materials is averaged over the expectable incident radiant fluxes; (iii)

the convective and radiant heat transfer coefficients are_ merely

estimated and taken to be the same for the flame to wall lining heat

141
transfer as well as hot gas layer to the ceiling; and (iv) the wall

combustibility parameter & as well as the functional form in which it

enters into our correlation are based on heuristic arguments rather than

on a reasoned hypothesis. Further study is required of these and other

relevant issues of the room fire scaling problem. Consideration of

further systematically conducted experiments with an improved hypothesis

and with better property values appears to be in order.

( d) Ambiguities related to moisture exist for further scrutiny.

For example, how does the moisture affect the conductivity, density and

specific heat in addition to the heats of combustion and pyrolysis?

( e) The ambient air relative humidity is purported to have an influence on the fire development process. We do not now know how to

account for this influence.

( f) The role of furnishings in the flashover process is another

issue not clear from the present correlation.

( g) Not withstanding these difficulties, it is indeed encouraging

that there exists a reasonable trend of dependency of flashover time on the initial fire and the wall combustibility.

Reports and Papers :

A. M. Kanury, "Scaling Correlations of Flashover Experiments," Final

Report Submitted to NBS-CFR for Grant NB 81 NADA 2021, 1983.

142
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 83

Institution : University of Pittsburgh

Contract Number : NB79NADA0009

Contract Title : Toxicity of Plastic Combustion Products

Principal Investigator : Yves Alarie, Ph.D.

Professor of Respiratory

Physiology and Toxicology

University of Pittsburgh

Pittsburgh, PA 15261

NBS Scientific Officer : Barbara C. Levin, Ph.D.

Technical Abstract

The objective of this project is to develop methods for

investigating the toxicity of thermal decomposition products from

synthetic or natural polymers.

Two major projects were completed this year. The first one consisted of correlating the data obtained for the toxicity of

thermal decomposition products from polyurethane foam, cotton batting

and polyester fibers obtained in the small scale decomposition system

with the results obtained on chair smoldering tests using the same materials used for the chair construction. Polyurethane was found

to produce the most toxic smoke in the small scale system as well

as during the chair smoldering tests. Cotton and polyester were

found to have similar toxic potencies when decomposed in the small

scale tests and in the chair smoldering tests.

The second project was conducted to evaluate delayed pulmonary

toxicity in guinea pigs following exposure to sub-lethal levels of

thermal decomposition products from polyvinylchloride (PVC). Also,

following the acute pulmonary effects, the animals were evaluated for

a period of up to 60 days to measure recovery, if any, from the

injury. We found PVC to be more acutely toxic to guinea pigs than to

mice. For this reason a slower decomposition rate (ll°C/min) was used instead of 20°C/min used in our previous work with mice. A

very severe pulmonary function decrement occurred following exposures

to the thermal decomposition products of PVC and this effect persisted

for 5 days for all exposure groups. Recovery was noted during the

following 14 days but complete recovery was not achieved in the group

exposed at the highest concentration when evaluated 57 days following

exposure. We are now completing a similar series of experiments

using Douglas fir in order to compare these two materials. Two

Special Reports were prepared. The first one is a discussion on how

143
to express toxicity data and their limitations. The second one is on animal models that can be used in studying the toxicity of thermal

decomposition products from polymeric materials.

Reports and Papers

Alarie, Y. Special Report to the National Bureau of Standards under

Research Grant NB79NADA0009: Toxicity of Plastic Combustion

Products. How to express "toxicity" for smoke obtained from decomposing polymers under thermal stress and the limitations of the data

obtained in such tests. Reprinted by: Subcommittee on Human

Services of the Select Committee on Aging, House of

Representatives. Committee Publication No. 97-368, U.S. Government

Printing Office, Washington, 1983.

Alarie, Y. Special Report to the National Bureau of Standards under

Research Grant NB79NADA0009: Toxicity of Plastic Combustion

Products. On animal models for evaluation of the toxicity of thermal

decomposition products from polymeric materials.

Mati jak-Schaper, M. and Alarie, Y. Toxicity of carbon monoxide,

hydrogen cyanide and low oxygen. J. Combustion Toxicol. 9, 21-61,

1982.

Alarie, Y., Stock, M.F., Mati jak-Schaper , M. and Birky, M.M.

Toxicity of smoke during chair smoldering tests and small scale tests

using the same materials. Fundam. Appl . Toxicol., in press.

Wong, K.L., Stock, M.F. and Alarie, Y. Evaluation of the pulmonary

toxicity of plasticized polyvinylchloride thermal decomposition

products in guinea pigs by repeated CO 2 challenges. Toxicol. Appl.

Pharmacol., in press.

Mati jak-Schaper, M., Stock, M.F. and Alarie, Y. Toxicity of thermal

decomposition products from commonly used polymers. Fire Science and

Technology, Vol.l, No. 1, 1982, ISSN0733-6721 . Available from Comtex

Scientific, 850 3rd Ave., New York, NY 10022. Microfiche only.

144


AGENDA

1983 ANNUAL

Tuesday, August

8:15 a.m. 9:00 a.m.

9: 20 a.m.

Chairman:

9:35 a.m.

9:50 a.m.

10:35 a.m.

11: 00 a.m.

11: 30 a.m.

12:00 noon

12:30 p .m

.

1: 00 p .m.

Chairman:

2:00 p .m.

2:45 p.m.

3:15 p.m.

CONFERENCE ON FIRE RESEARCH HONORING PROFESSOR HOWARD EMMONS

CENTER FOR FIRE RESEARCH

NATIONAL ENGINEERING LABORATORY

NATIONAL BUREAU OF STANDARDS

August 23, 24, 25, 1983

23

Registration, Green Auditorium, Lobby

Introduction - J.E. Snell, Director, CFR/NBS

Remarks - F. Villella, Director, National

Emergency Training Center

Session 1. Modeling Fire Growth in Compartments

W. Berl, Applied Physics Lab, Johns Hopkins University

Historical Overview of Fire Research - H. Hottel,

Massachusetts Institute of Technology

Keynote: "A Perspective on Modeling Fire Growth in

Compartments" - J. Quintiere, CFR/NBS

Coffee Break, Employee Lounge

"Characteristics of Fire in a Forced Ventilation

Enclosure" - N.J. Alvares, K.L. Foote, and P.J. Pagni

"Zone Modeling of Forced Ventilation Fires" - H. Mitler,

CFR/NBS (formerly Harvard)

"Modeling of Turbulent Bouyant Flows in Aircraft Cabins"

- K.T. Yang, J.R. Lloyd, A.M. Kanury, K. Satoh,

University of Notre Dame

"Zone Modeling of Aircraft Cargo Compartment Fires" -

C. McArthur, University of Dayton Research Institute

Lunch, NBS Cafeteria

Session 2. Flame Phenomena and Spread

R. Fristrom, Applied Physics Lab, Johns Hopkins University

Keynote: "Flamespread Modeling" - C. Fernandez-Pello

,

University of California, Berkeley

"Numerical Modeling of Wall Burning" - F. Tamanini,

Factory Mutual Research Corp.

"Wind Aided Flame Spread Along a Horizontal Fuel Slab:

Ceiling and Floor Geometries" - F. Fendell, TRW, Inc.

3:45 p.m. Coffee Break, Employee Lounge
Session 2. Flame Phenomena and Spread (Continued)

4:15 p .m

.

"Transient Fire Spread on Horizontal Surfaces of Wood" - A. Atreya, Michigan State University (formerly

Harvard)

4:45 p . m. "Flame Heights in Turbulent Wall Fires" - M.A. Delichatsios

,

Factory Mutual Research Corp.

5:15 p .m. Adj ourn

6: 30 p.m. Barbeque at Smokey Glen

Wednesday, August 24

Session 3. Structure of Diffusion Flames and Radiation

Chairman: C. Tien, University of California, Berkeley

9: 00 a .m. Keynote: "Radiation from Diffusion Flames" - J . de Ris,

9:45 a.m. Factory Mutual Research Corp.

"Measurements on Gaseous-Fuel Pool Fires with a FiberOptic Absorption Probe" - G.M. Markstein, Factory

10:15 a.m. Mutual Research Corp."Soot and Radiation in Combusting Boundary Layers" - R.A. Beier, P.J. Pagni, and C.I. Okoh, University of

California, Berkeley

10:45 a.m. Coffee Break, Employee Lounge

11:15 a.m. "Sooting Counterflow Diffusion Flames with Varying

Oxygen Index" - U. Vandsburger, I. Kennedy, and

11:45 a.m.

I. Glassman, Princeton, University

"Several Numerical Schemes Potentially Capable of

Examining Elliptic-Type Flows" - T.M. Shih, University

of Maryland

12: 15 p.m. "The Prediction of the Onset of Layer Burning in

Compartment Fires" - C. Beyler, Harvard University

12:45 p.m. Lunch, NBS Cafeteria

Chairman:

Session 4. Fire Plumes

J. Prahl, Case Western Reserve University

2:00 p.m. Keynote: "Bouyant Plumes: Entrainment Rates and

Interactions with Boundaries" - E. Zukoski, California

2: 45 p.m.

Institute of Technology

"Some Experimental Aspects of Turbulent Diffusion Flames

and Fire Plumes Along a Wall and in a Corner of Walls"

- Y. Hasemi, Japan Building Research Institute
Session 4. Fire Plumes (Continued)

3:15 p.m. "On the Significance of a Wall Effect in Enclosures

with Growing Fires" - L.Y. Cooper, CFR/NBS

3:45 p.m. Coffee Break, Employee Lounge

4:15 p.m. "Nonluminous Flame Radiation in Turbulent Bouyant

Axisymmetric Flames" - S-M. Jeng, M-C. Lai and

4: 45 p.m.

G.M. Faeth, Pennsylvania State University

"Calculations of Three Dimensional Bouyant Plumes in

Enclosures" - H.R. Baum, CFR/NBS and R.G. Rehm, CAM/NBS

5:15 p.m. Adj ourn

6: 30 p.m. Banquet - Gaithersburg Marriott Hotel

G. Carrier - Master of Ceremonies

Speakers - R. Gross, Dean, Columbia University

R. Friedman, Vice President, Factory

Mutual Research

J. Lyons, Acting Deputy Director, National

Bureau of Standards

Thursday, August 25

Session 5. Extinction and Suppression

Chairman: R. Gann, CFR/NBS

9:15 a.m. Keynote: "Actuation of Extinguishing Systems" - D. Evans,

CFR/NBS

9:45 a.m. "Numerical Modeling of the Interaction Between a Droplet

Spray and a Bouyant Plume" - R.L. Alpert, Factory

Mutual Research Co.

10:15 a.m. "Investigation of Completeness of Combustion in a Wall

Fire" - M. Sibulkin and S.F. Malary, Brown University

10:45 a.m. Coffee Break, Employee Lounge

11: 30 a.m. "Extinction of Large Jets" - B.J. McCaffrey, CFR/NBS

Session 6. Data for Models

Chairman: A. Fowell, CFR/NBS

12:00 noon Keynote: "Data for Room Fire Models" - J. Rockett,

CFR/NBS

12:45 p.m. Lunch, NBS Cafeteria

1:45 p.m. "Recent Developments in Fire Testing for Fire Growth

in Buildings" - P.H. Thomas, British Fire Research

Station
Session 6. Data for Models (Continued)

2:30

3:00

3:30

4:00

.m. "The ASTM Room Fire Test and Model" - R.B. Williamson,

F.L. Fisher, and F. Mowrer, University of California,

Berkeley

.m. "Heat Release Rate Measurements with the Cone

Calorimeter" - V. Babrauskas, CFR/NBS

.m. Remarks - H. Emmons

Introduction by J. Lyons, NBS

.m. Remarks - J. Snell, CFR/NBS

4:15 p .m

.

Adjourn
GENERAL INFORMATION

WELCOME

The people at the Information Desk located in the registration area will be

pleased to assist you. They are able to answer questions about the conference , transportation, and sightseeing in the Gaithersburg and Washington

areas

.

BUS TRANSPORTATION

Tuesday, August 23, 1983

8:00 a.m. Buses leave

5:15 p.m. Buses leave

6:15 p.m. Buses leave

9:30 p.m. Buses leave

Wednesday, August 24, 1983

8:15 a.m. Buses leave

5:15 p.m. Buses leave

Thursday, August 25, 1983

8:15 a.m. Buses leave

hotels for NBS

NBS for hotels

hotels for Smokey Glen

Smokey Glen for hotels

hotels for NBS

NBS for hotels

hotels for NBS

TRANSPORTATION TO THE HOTEL ON THURSDAY, AUGUST 25

If you need transportation to the hotel on Thursday, please fill out a

request form and return it to the Registration Desk NO LATER THAN CLOSE OF

BUSINESS, WEDNESDAY, AUGUST 24 .

TRANSPORTATION TO AIRPORTS

Transportation will be arranged from NBS to Washington National, Dulles

International, and Baltimore Washington Airports at the conclusion of the

Conference. Reservations must be made by completing a request form and

returning it to the Registration Desk NO LATER THAN NOON, WEDNESDAY,

AUGUST 24 . Departure schedules will be posted near the Registration Desk

on Thursday morning. Persons wishing to make use of this service should

bring their luggage with them and store it in the Meeting room for the day.

COMMUNICATIONS

Workshop Main Desk: The telephone number for contact with the Conference

is (301) 921-3330 or 3340.
Messages ; There will be a message board in the Registration Desk area. Please check this frequently during the conference. Attendees will not be

called out of the sessions to receive telephone calls except in emer- gencies .

Telephones : Pay phones are located at the end of the corridor near the

Green Auditorium.

COFFEE BREAKS

Coffee and doughnuts will be available before the sessions each morning.

Coffee and cold drinks will also tie available during mid-morning and

mid-afternoon breaks. For attendees who may wish to have a more substantial breakfast, it may be purchased in the NBS Main Cafeteria beginning at

7:30 a.m.

LUNCHEONS

Attendees will use a special section of the NBS Cafeteria for lunch each

day. Lunch tickets are in the registration packet. Additional tickets for

guests of registrants may be purchased at the Registration Desk.

SOCIAL FUNCTIONS

On Tuesday, August 23, conference attendees will be bussed to an informal

country style farm dinner at Smokey Glen Farm, near NBS. Dress will be

casual (jeans are appropriate)

.

The official Conference Banquet will be held on Wednesday, August 24, at

the Gaithersburg Marriott Hotel. The cash bar will begin at 6:30 p.m. , and

the dinner, at 7:30 p.m.

After dinner, R. Gross, Dean, Columbia University; R. Friedman, Vice

President, Factory Mutual Research, and J. Lyons, Acting Deputy Director,

NBS, will speak.

Tickets for the Smokey Glen dinner and the Marriott banquet are included in

the registration packet. Additional tickets for guests of registrants may

be purchased at the Registration Desk.

MISCEIT I ANEOUS

The following services are located in the basement of the NBS Administration Building. Please take the elevator frcm the Main Lobby.

Bank (Room A-28) - hours: 9 a.m. - 3 p.m.

Beauty and Barber Shop (Room C-31)

Newspaper and Sundry stand (adjacent to the elevators)

NO SMOKING, POOD, OR BEVERAGES PERMITTED IN THE AUDITORIUM

to Frederick

t

north

Rte 118

3 miles

DIRECTIONS to SMOKEY GLEN FARM

Take the Capitol Beltway (1-495) to 1-270. Drive north to- ward Frederick. Follow signs to Route 28 (Rockville Exit).

It is also marked "State Police." Head west on Route 28

toward Darnestown. At a distance of 5 miles you will pass Quince Orchard Shopping Center on your right. Continue west on Route 28 for Vi mile to Riffleford Road. Turn right

and proceed ’/* mile to Smokey Glen Farm. Follow the signs

to vour picnic area. .. . Capitol Baltway 1-495

Gaithersburg

Rockville