REFERENCE

NBS

PUBLICATIONS

NAT'L INST. OF STAND & TECH

AlllOb 0371LD

NBSIR 85-3136

Summaries of Center for Fire

Research Grants and In-House

Prog rams - 198

4

Sonya M. Cherry, Editor

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

April 1985

Final Report

U S. DEPARTMENT OF COMMERCE

-ATIONAL BUREAU OF STANDARDS

100

,U56

85-3136

1985

NBSIR 85-3136

SUMMARIES OF CENTER FOR FIRE

RESEARCH GRANTS AND IN-HOUSE

PROGRAMS - 1984

NATIONAL BUREAU

OF STANDARDS

LIBRARY

Sonya M. Cherry, Editor

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

April 1985

Final Report

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS. Ernest Ambler. Director

TABLE OF CONTENTS

Page

ABSTRACT 1

CENTER FOR FIRE RESEARCH PROGRAMS

Ad Hoc Working Group of Mathematical Fire Modeling 2

Compartment Fire Modeling 3

Exploratory Fire Research 8

Fire Growth and Extinction 14

Fire Performance and Validation 20

Fire Safety Performance 24

Fire Toxicology 28

Furnishings Flammability 34

Smoke Hazard 37

GRANTS AND CONTRACTS

American Institute of Architects

A Computerized Model for the Simulation of

General Fire Emergency Evacuations 40

Brown University

Soot Dynamics in Flames 43

Brown University

Study of Effects of Material Properties on Flaming Combustion of Charring Fuels 47

California Institute of Technology

Experimental Study of Environment and

Heat Transfer in a Room Fire 51

Case Western Reserve University

Experimental and Analytical Study of

Fire Sprinkler Scaling Laws 55

Case Western Reserve University

Flame Spread and Spread Limits 58

l
Page

Clemson University

Ternary Reactions Among Polymer SubstrateOrganohalogen-Ant imony Oxides in the Condensed

Phase Under Pyrolytic, Oxidative and Flaming

Conditions 60

Colorado School of Mines

Characterization of Aerosols from Fires 63

Factory Mutual Research Corp.

Calculated Interaction of Water Droplet Sprays

with Fire Plumes in Compartments 66

Factory Mutual Research Corp.

Determination of Fuel Parameters for Fire

Modeling 70

Factory Mutual Research Corp.

Effects of Water Discharge Rate and Drop Size

on Spray Cooling in Residential Fires 72

Factory Mutual Research Corp.

Experimental Fire and Smoke Verification Data

for Multiroom and Corridor Conditions 75

Factory Mutual Research Corp.

Prediction of Fire Dynamics 78

Harvard University

Prediction of Upper Layer Composition in

Transient Compartment Fires . 87

The Pennsylvania State University

An Investigation of Turbulent Fires on Vertical and Inclined Walls 90

Princeton University

Flow Field Effects on the Sooting Structure

of Diffusion Flames 95

Rutgers, The State University of New Jersey

Negatively Buoyant Flows Generated in

Enclosure Fires 97

Southwest Research Institute

Analysis of Hazards to Life Safety in Fires:

A Comprehensive Multi-Dimensional Research

Program 100

Stanford University

The Behavior of Furniture Frames During Fire 104

ii
Page

TRW

Modeling of Wind-Aided Flame Spread 109

University of California, Berkeley

Fire Propagation in Concurrent Flows 113

University of California, Berkeley

Flame Radiation 117

University of California, Berkeley

Fire Modeling 120

University of Dayton Research Institute

Mathematical Modeling of Furniture Fires 124

University of Florida

Network Models of Building Evacuation:

Development of Software System - Year

Three 127

University of Minnesota

Method and Apparatus for Quantitative

Fit Test of Respirators 131

University of Montana

Chemistry of Smoldering Combustion 133

University of Notre Dame

Scaling Correlations of Flashover

Experiments 137

University of Pittsburgh

Toxicity of Plastic Combustion Products 141

APPENDIX A, AGENDA, 1984 ANNUAL CONFERENCE ON FIRE RESEARCH 143

APPENDIX B, LIST OF PARTICIPANTS 1 U 9

iii

Summaries of Center for Fire Research Grants

and In-House Programs - 1984

October 1984

Abstract

This report was prepared for distribution at the 1984

Annual Conference on Fire Research, October 17-19 > 1984.

It 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: Evacuation; combustion; extinction; fire

models; flame spread; ignition; polymers;

smoke; soot; toxicity.
AD HOC WORKING GROUP OF MATHEMATICAL FIRE MODELING

CENTER FOR FIRE RESEARCH

FY 84

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 Benj amin-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
COMPARTMENT FIRE MODELING

FIRE SAFETY TECHNOLOGY DIVISION

CENTER FOR FIRE RESEARCH

FY 84

Professional Personnel

Leonard Y. Cooper, Head

John A. Rockett, Senior Research Scientist

Henri E. Mitler, Physicist

David W. Stroup, Fire Protection Engineer

Masahiro Morita, Guest Worker (Tokyo Science University)

Anne Woodhouse, Guest Worker (University of Maryland)

Program Objectives

(1) Develop, maintain, improve and provide assistance in the use of

benchmark Compartment Fire Model computer codes. Provide assistance in

the improvement of applications-oriented compartment fire simulation

models, and measure their performance against the benchmark codes.

(2) Develop and maintain a library of submodel algorithms for general use

in compartment fire models.

(3) Formulate, develop, and establish the validity of new and improved

analytic /computational compartment-fire-phenomena submodel algorithms

for use in compartment fire simulations.

Scope

The work focuses on the development of benchmark computer codes (s) which

would be useful in simulating the phenomena which occur in compartment fire

scenarios. The term "benchmark computer code" is intended to connote a welldocumented computer code which: a) is based on physics and numerics of proven

reliability; b) is numerically robust; and c) is user-friendly in the sense

that it can be used with relative ease by researchers and professional fire

safety practitioners, and that it can be transferred to and used with

computer hardware facilities readily available to the fire science/technology

community.

While the benchmark computer code(s) would be up-to-date in the sense of

including algorithms which describe the details of fire phenomena currently

under investigation in the Fire Research Community, they would not be

responsive to forecasts of future research thrusts. In terms of the complexity of compartment configurations, the capability of the new generation of

benchmark code(s) would be limited to the simulation of fire-generated

environments only in those compartment spaces which affect actual fire

development, e.g., in rooms of fire involvement and "freely connected"

adjacent spaces. In terms of the level of "user-friendliness", the code(s)

would be useful to researchers and practitioners with relatively high

levels of commitment and technical skill.

3
Proj ects

1. Compartment Fire Models

Single-Room Fire Simulations . The Harvard single-room fire model has been

operational at NBS for some years. It has been used both for demonstration

calculations and as a test bed for new modeling concepts. The "official"

Harvard V, model has been enriched successfully. The results of this have

led to two new and different versions of the model; namely, versions 5.2 and

5.3. The enrichments include:

o restructuring of the physical subroutines so that they are interchangeable with other compartment fire simulation computer codes (5.2).

o restructuring the code in a way that facilitates the incorporation of new or different equation solvers (5.2).

o the ability to include the dynamics of forced ventilation in the

simulation (5.3).

NBS/Harvard 5.2 has been applied in two practical problem areas. The first

of these involves the simulation of full-scale fire tests carried out at NBS

for the U.S. Park Service. In this study, physically reasonable input parameters resulted in a good simulation of the experimental data. Using the same

input parameters, the simulation was then used to predict fire behavior in rooms of different sizes from that included in the test program. This

allowed the experimental data base to be extended to cases which would have

been very expensive, and perhaps impractical to have tested.

The other application of NBS/Harvard 5.2 was to a design problem associated

with sizing the ventilation fans of a proposed new Navy firefighter training

facility. A series of simulations of the facility were run with different

ventilation conditions. Results included predicted temperatures and gas

compositions in the training facility as the amount and location of fire gas

extraction were varied. From this, a rational choice of ventilating fans was

possible.

Harvard 5.3 was used to simulate the fire environments generated during tests

in the full-scale, ventilated, fire test facility of the Lawrence Livermore

National Laboratory.

Additional progress was made in making the ASET (Available Safe Egress Time)

computer program more user-friendly. This work is now continuing as a joint

activity with the Fire Safety Performance Group of CFR. ASET has found much

application over the course of the last year.

In a special study for the FAA a model of the external-fuel-spill-fire - generated environment in aircraft cabins was developed and used to establish an analytic methodology for simulating the thermal response of cabin ceiling

materials. The analysis was developed in conjunction with experimental data

available from FAA fire tests on a full-scale, wide-body, aircraft fuselage.

In another special study for the U.S. Park Service a simple graphical method for

designing smoke control systems in atrium-like configurations was developed.

4
Multi-Room Fire Simulation (based on Harvard VI) . Harvard VI was brought to

NBS in usable form during the summer of 1983. It was made operational on the

CFR computer, made to conform strictly to the ANSII FORTRAN 77 standard, and

a series of minor errors were corrected. After adding several enrichments,

it has been "calibrated" against some available NBS multi-room fire test

data. The agreement between the tests and the simulations was very good. As

a part of this effort, an extensive debugging capability was also added to

the computer code. A separate plot package, originally developed for

NBS/Harvard 5.2, has been adapted to the more general demands of the new

NBS/llarvard VI. Further enrichments suggested by the calibration simulations

are being added at this writting.

Cooper, L.Y., "Smoke Movement in Rooms for Fire Involvement and Adjacent

Spaces", presented at 1983 SFPE Symposium on Smoke-Its Chemistry, Physics and

Control Through Engineering, Fire Safety Journal, ]_, 1 (1983).

Cooper, L.Y., "The Development of Hazardous Conditions in Enclosures with

Growing Fires", Combustion Science and Technology, 33^, (1983).

Cooper, L.Y. , "Methods of Designing and Evaluating Facilities for Fire Safety",

presented at the 7th Joint Meeting of the UJNR Panel on Fire Research and

Safety (1983), and to appear in the Proceedings of the Meeting.

Cooper, L.Y., "The Need and Availability of Test Methods for Measuring the

Leakage Characteristics of Door Assembilies", NBSIR 84-2876, presented at the

1984 ASTM/FSPE Symposium on Applications for Fire Science to Fire Engineering,

to appear in Fire Science.

Cooper, L.Y., Nelson, H.E., and Thome, S., "National Park Service Full-Scale

Burns: Analysis and Insights Gained", a video tape report to the U.S. National

Park Service (1984).

Cooper, L.Y., and Stroup, D.W., "ASET: A Computer Program for Calculating

Available Safe Egress Time", presented at 1984 SFPE Symposium on Computer

Applications in Fire Protection: Analysis, Modeling and Design, to appear in

Fire Safety Journal.

Cooper, L.Y., "The Thermal Response of Aircraft Cabin Ceiling Materials During

a Post-Crash, External Fuel-Spill, Fire Scenario", to appear as an NBSIR 84-

2912 and as Chapter 2 in a NBS report to the FAA: "The Role of Aircraft Panel

Materials in Cabin Fires and Their Properties," presented to the FAA, to be

presented at the 23rd AIAA Aerospace Sciences Meeting (1985), to be submitted

for publication.

Cooper, L.Y., "An Interim Buoyancy Smoke Control Approach (for Atrium-like

Arrangements", Appendix B of NBSIR under review: Fire Safety Evaluation

System for National Park Service Accommodations, H.E. Nelson, et al.

Rockett, J.A. , "Park Service Room Fire Test Simulations, Using the Harvard

Level 5.2 Computer Fire Model", NBSIR 83-2805.

Baum, H. , and Rockett, J.A., "Analysis of Forced Ventilation in Container

Ship Holds", Journal of Fluid Mechanics 142 , pp. 309-342 (1984).

5
Rockett, J.A., "Data for Room Fire Models", to appear in Combustion Science

and Technology.

Rockett, J.A., "Two Approaches to the Analysis of Actual Fires", presented at

1984 SFPE Symposium on Computer Applications in Fire Protection: Analysis,

Modeling and Design, to appear in Fire Safety Journal.

Mitler, H.E., "Zone Modeling of Forced Ventilation Fires", Combustion Science

and Technology, _39, 88 (1984).

Mitler, H.E., "The Harvard Fire Model", presented at 1984 SFPE Symposium on Computer Applications in Fire Protection: Analysis, Modeling and Design, to

appear in Fire Safety Journal.

Stroup, D.W., "Heat-Transf er-Related Calculations for the Jefferson National

Memorial Historical Site", Appendix A of NBSIR under review: Jefferson

National Memorial Historical Site Analysis of Impact of Fire, H.E. Nelson,

et al.

2. Compartment Fire Model Library of Submodel Algorithms and Associated

Computer Subroutines

This project involves a series of short- and long-term activities. These will

be initiated by: a) merging the physical subroutines of the NBS/Harvard

computer codes into a single, portable, subroutine library; b) reviewing the

subroutine algorithms of the NBS/Harvard computer codes, and identifying those

which are of "benchmark" quality (the term "benchmark quality algorithm is

intended to suggest an algorithm which would generally be considered to provide

reliable physical simulations, and an algorithm which would not likely be

substantially improved as a result of indepth review and analysis of existing

fire-science-related literature); c) developing and proposing a format

for a Catalogue of Compartment Fire Submodel Algorithms. Developing and

proposing a mechanism for publication, distribution and revision of the

Catalogue. The Catalogue will be for general use in zone comparment fire

models

.

The project has only recently been initiated and products have not yet been

generated.

3. Compartment-Fire-Generated Flow Dynamics, Flame Spread/Growth and Heat

Transfer: Submodel/Algorithm Development and Ventilation

NBS/Harvard 5.2 was used to evaluate each of five different published plume

entrainment models when used in single-room fire simulations. A series of

simulations were run for both small fires, for which experimental room gas

flow measurements were available, and for larger fires where experimental

data is not now available. The fire plume models led to simulations which

were in moderate agreement with the small fire test data. There was a wide

disparity in the predicted results for the large fire. To select from

among these several models additional experimental data for large area

and heat-release-rate fires will be needed.

The dynamics of forced ventilation in the context of a two-layer compartment

fire model has been analyzed, and an algorithm for simulating the phenomenon

6
was developed. This was used to enrich Harvard 5.3. An algorithm for

simulating the effect of roof venting under natural convection conditions was

also developed. This latter algorithm has not yet been incorporated into the

full compartment fire model(s).

Work has been recently initiated on a new, reduced-scale, experimental program

where the thermal response of different ceiling constructions positioned above

fires of different strengths and fire-ceiling separations will be measured.

This experimental program will complement continuing theoretical activities

which are being carried out to formulate, develop and validate algorithms for

simulating compartment-fire-generated flow dynamics and heat transfer.

A theoretical study of the structure of wall fires has been undertaken from

the point of view that the results be consistent with available experimental

data, and useful in an algorithm which is simple enough for use in full

compartment fire models.

Cooper, L.Y., "On the Significance of a Wall Effect in Enclosures with

Growing Fires", to appear in Combustion Science and Technology.

Cooper, L. Y., "A Buoyant Source in the Lower of Two, Homogeneous, Stably

Stratified Layers - A Problem of Fire in an Enclosure", presented at 1983

ASME Symposium on Modeling at Environmental Flow Systems, and at the 20th

International Symposium on Combustion (1984), to appear in the Proceedings of

the latter Symposium.

Cooper., L. Y. , "The Thermal Response of Unconfined Ceilings Above Growing

Fires and the Importance of Convective Heat Transfer", NBSIR 84-2856,

presented at 22nd National Heat Transfer Conference (1984) , and at the 1984

CFR Annual Conference on Fire Research, to be submitted for publication.

Rockett, J.A., "A Comparison of Plume Entrainment Models", manuscript under

review.

Mitler, H. E. , "On Roof Vents", manuscript under review.

Associated Grants and Contracts

1. Yogesh Jaluria - Rutgers - The State University of New Jersey,

"Negatively-Buoyant and Penetrative Flows Generated in Enclosure Fires."

2. Colin H. Marks - University of Maryland, "Transient Heat Transfer in

Ceiling Jets."

7
EXPLORATORY FIRE RESEARCH

FIRE MEASUREMENT AND RESEARCH DIVISION

CENTER FOR FIRE RESEARCH

FY 84

Professional Personnel

Walter M. Shaub, Head

James E. Brown, Research Chemist

George W. Mulholland, Research Chemist

Takashi Kashiwagi, Materials Research Engineer

W. Gary Mallard, Research Chemist

William J. Parker, Physicist

Thomas J. Ohlemiller, General Engineer

William M. Pitts, Research Chemist

Kathleen E. Werner, Chemist

Kermit C. Smyth, Research Chemist

Atsushi Inaba, Guest Worker

J. Houston Miller, Faculty Research Associate

Program Objectives

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

underline macroscopic fire phenomena. The research embraces broad

areas covering both solid and gas phase processes, with particular

attention to polymer degradation, the effect of thermal 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 thermal radiation. Efforts are directed toward

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 ect

1. Polymer Gasification and Ignition

The mechanisms of thermal degradation and thermal oxidation of poly (methyl

methacrylate) (PMMA) are being studied by measuring the molecular weight

of rapidly quenched samples thermally degraded in nitrogen and air in the

range of temperatures between 200°C and 325°C. Present work shows that thermal

oxidation reduces the degree of polymerization much faster than does thermal

8
degradation. Random scission has been found to be the initiation step for both

thermal degradation and oxidative degradation. The activation energy for the

random scission initiation is 233 kj/mole for thermal degradation and 64 kj

/

mole for oxidative degradation. The average zip length decreases from 2620

to 1340 with an increase in temperature from 258°C to 324°C for thermal degradation. The average zip length increases from 20 to 102 with an increase in

temperature from 205°C to 251°C for thermal oxidative degradation. A reasonable value of activation energy for the termination reaction in nitrogen, 104

kj/mole, is obtained only for the assumption of first order termination.

Weight loss rates and surface temperature of Lucite and Plexiglas G have been

measured in air and nitrogen at a radiant flux of 2.2W/cra? from the blackbody

radiant source. Results show that the change in surface temperature with time

is almost the same for both samples either in nitrogen or in air, there is no difference in surface temperature between the two samples. However, the rates

of weight loss are significantly different for the samples degraded in nitrogen:

Lucite degrades with much faster rates than Plexiglas G. Plexiglas G shows a two step type degradation pattern which was recognized by thermal analysis of

a small sample. The weight loss of Plexiglas but not Lucite shows a strong

oxygen dependency in the gas phase. This trend is consistent with that observed

by a thermal analysis study. These observations indicate that the chemical

degradation mechanism does not change from slow heating rates of 0.5 ^ 5°C/m

in the thermal study to typical heating rates of N tens °C/S. of degrees

per second in fire conditions.

A theoretical model is being developed to calculate changes in weight loss and

in the molecular weight distribution of a polymer, including random scission

initiation, depropagation and termination reactions without any transport processes. This calculation simulates results of thermal analysis of the polymer.

The model uses about 40,000 ordinary differential equations. Each differential

equation is written with respect to an individual degree of polymerization. In

addition, work on the theoretical description of the pyrolysis of (certain)

polymers is nearly complete.

Experiments are being carried out to investigate the effect of terminal vinyl

groups on the stability (thermal) of PMMA. GPC chromatograms of thermally

stressed or non-stressed samples have been made. A glass apparatus has been

designed in which hydrogenation of the PMMA terminal vinyl groups will be made

in preparation for further studies.

Kashiwagi, T., Hirata, T. and Brown, J.E., "Thermal and Oxidative Degradation

of Poly (methyl methacrylate) - Molecular Weight", submitted to Macromolecules

(1984)

.

Kashiwagi, T. and Hirata, T. , "Thermal and Oxidative Degradation of Poly (methyl

methacrylate) II. Weight Loss", submitted to J. Poly. Sci. Macromolecules (1984).

2. Smoldering Combustion of Cellulosics

The propensity for smoldering exhibited by cellulosic materials continues to be

a subject of major concern. Smoldering combustion is driven by exothermic

oxygen attack on the surface of organic materials; wood-based materials such

as cellulosic insulation are particularly prone to this attack. The process is

slow but self-sustaining once initiated. It poses a life threat as a cop ion:

9
source of toxic gases. Also, it provides a relatively easy pathway to flaming

combustion that is not precluded by flame retardants. It is this latter aspect

smoldering as an initiator of flaming—which is of greatest concern with cellulosic insulation materials. Smolder to flaming tests are presently being conducted

using unretarded cellulosic insulation material. Though it comes from the same manufacturer, a batch may exhibit somewhat differing behavior from the last

batch. This is probably a consequence of a different composition of inorganic

ions in the insulation stock.

The study of the low temperature (295-315°C) pyrolysis and oxidation of cellulose continues. Our present goal is to "come up" with some sort of mechanism

to account for the endo and exothermic heats of reaction observed in DSC

experiments with N2 and O2 respectively. We are analyzing for CO, C02 methyl

alcohol, H 2O and levoglucosan, the compounds we believe account for most of the

weight loss. Since we are interested in solid phase reactions, the role of gas

phase reactions in the distribution of products had to be ascertained. This was accomplished by varying the flow rate (0.24-1.4 1/min) . of the carrier gas

in our tube furnace. Our present work suggests gas phase oxidation is not

affecting product distributions for experiments with flow rates greater than

1.0 1/min. We are now performing experiments with N2 and air at 295, 305 and

315°C with the expectation that the product distribution will provide insights

as to a mechanism.

Physical property data for char forming materials are being carefully developed

to support an effort to be able to predict the heat release rate of wood. A new pyrolyzer is being constructed for this purpose. This will be used to obtain mass generation rate data and heats of combustion of the volatile pyrolysis

products from wood components (cellulose, hemicellulose and lignin) using the new pyrolyzer and the gas sampling system in the cone calorimeter. The thermal

property data for various soft and hardwoods will be obtained as a function of

temperature and fractional mass loss. A model will be used to predict the heat

release rates of woods in a vertical orientation as a function of incident flux

and specimen thickness. The predictions of the model will be compared against

cone calorimeter results.

Parker, W.J., "Calculations of the Heat Release Rate By Oxygen Consumption for

Various Applications", submitted to Journal of Fire Sciences (1984).

Ohlemiller, T. , "Modeling of Smoldering Combustion Propagation", submitted to

Progress in Energy and Combustion Science .

Ohlemiller, T. , "Structure of a Smoldering Combustion Wave in a Permeable

Horizontal Fuel Layer", in preparation.

Ohlemiller, T. , "Modeling of Smoldering Combustion Propagation", NBSIR 84-2895,

National Bureau of Standards, Washington, D.C., June 1984

3. Products of Wood Combustion

The objective of this research is to understand 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

10
its residential alternate fuels program. Our studies elucidate the chemical

processes occurring in the fuel itself under controlled pyrolysis. High

resolution nuclear magnetic resonance spectra clearly show the evolution

from a cellulosic/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.

Radiative heating tests on various woods are being conducted. We are studying

the effects of flux, oxygen, grain orientation, water level, wood type, wood

thickness and exposure time effects on emitted products. Major organic species

are being primarily identified by GC-MS. We plan to utilize as many as five

thermocouples to characterize the evolving thermal wave in the wood. This

information and the time dependent mass flux will be compared with the predictions of a theoretical model (for non-oxidative atmospheres first)

.

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 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

fifth 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.

A series of optical and mass spectrometric profile measurements have been completed

for methane/air diffusion flames on our Wolfhard-Parker burner. We have used fluorescence to monitor OH, C^ , and polycyclic hydrocarbons (three ways), multiphoton ionization to detect polycyclics and small soot particles and Rayleigh-mie

scattering to observe the emergence of large soot particles. In addition, mass spectrometric profiles of CO^ , H^O, methane, acetylene, butadiene, benzene,

toluene, diacetylene, triacetylene, vinyl acetylene, methylacetylene, and allene

have been taken. These results clearly delineate the region of soot nucleation:

soot particles, first appear on the high temperature, radical-rich side of a zone containing numerous pyrolysis products. Velocity measurements using laser

doppler velocimetry for the same flame conditions are being planned.

In addition to species characterization studies, physical properties of soot are being investigated. The kenetics of cluster aggregation and structure of the

resulting clusters have been studied using a "Brownian dynamics" computer simulation of conditions appropriate for soot growth. A free radical soot growth model

has been extended to account for the pyrolysis of the fuel in a more realistic

manner. The flow pattern of a starting plume in an enclosure has been measured

using an aerosol tracer. The heat loss to the walls and ceiling in the smoke

dynamics facility has been measured as a function of time as the smoke fills tin- enclosure. A study of smoke detector sensitivity to a dioctylsebacate aerosol

indicated one of three tested to have adequate sensitivity for use in a quantitative test for respirator face mask fit.

Dobbins, R.A. and Mulholland, G.W. , "Interpretation of Optical Measurements < t Flame Generated Particles," Comb. Sci. and Tech., 40^, 175 (1984).

11
Mountain, R. and Mulholland, G.W., "Stochastic Dynamics Simulation of Particle

Aggregation," Proc . of First International Conference on Kinetics of Aggregation and Gelation, D.P. Landar Editor, (1984).

Marx, E. Mulholland, G.W., Size and Refractive Index Determination of Single

Polystyrene Spheres," J. of Research NBS, 88^, 321 (1983).

Baum, H.R., Rehn, R.G., Mulholland, G.W., "Prediction of Heat and Smoke

Movement in Enclosure Fires," Fire Safety Journal 6, 193 (1983).

Miller, J.H., Mallard, W.G., and Smyth, K.C., "Intermolecular Potential Calculations for Polycyclic Aromatic Hydrocarbons," J^. Phys . Chem . (in press).

Miller, J.H., Smyth, K.C., and Mallard, W.G., "Calculations of the Dimerization

of Aromatic Hydrocarbons; Implications for Soot Formation," Twentieth Symposium

(International) on Combustion (accepted)

.

Smyth, K.C., Mallard, K.C., and Miller, J.H., "Multiphoton Ionization Detection

of Molecules in Flames," SPIE Symposium on Laser Chemistry and Diagnostic

(in press)

.

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. This project is designed

to study chemically reacting turbulent flows by systematically investigating

the effects of density differences, temperature differences, and heat release

on turbulent mixing.

Our research has shown that hot-wire and film anemometry can be applied to

mixtures if the mixture compositon is known. However, despite the wide spread use of these instruments and a great deal of previous research, it has been

necessary to undertake a fairly detailed investigation of their response in

different gases and mixtures in order to be confident of their behavior.

Calibration measurements have been made in binary gas mixtures. The heat

transfer in these mixtures is not predicted well by the extrapolated pure

gas results. We have postulated that these differences are due to thermal

diffusion effects in the mixtures and are using theories especially developed

for this study in an attempt to quantitatively predict the magnitude of such

effects. The results of our calibration studies have highlighted the complexity

and poorly understood nature of the response of heated filament anemometers.

Such problems were not evident as we began our investigation. The results of

this study have enabled us to understand hot-wire and film response in different

gases much better. Such an understanding is necessary for accurate velocity

measurements using our new technique.

There has been a great deal of recent interest in making line and two-dimensional

measurements of concentration in turbulent flow fields. These measurements

12
combine laser based optical probes with the use of new and powerful solid state

detector arrays.

The studies done thus far have yielded a great deal of information about turbulent flow fields and have demonstrated the vast potential of these techniques

for contributing to an improved understanding of chemically reacting turbulent

f low fields. However, it is fair to say that the technique is still severely

limited by laser, detector, and computer constraints. For example, the measurements reported thus far have been single shot and measurement accuracy has been

poor. We are currently developing an experiment in which line measurements of

concentration are to be made in a turbulent flow of two gases. The design goals

of this experiment are (1) a 0.2 ms time resolution, (2) a 0.2 mm spatial resolution, and (3) a concentration accuracy of 4% for each individual measurement.

A system has been designed which should meet these goals and we have begun

purchasing the necessary components for its construction. This new experiment

will allow much more detailed studies of density effects on turbulent mixing.

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

Scattering to the Study of Turbulent Mixing", NBSIR 83-2641 and Journal of

Fluid Mechanics 141, 391(1984).

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,

Karlsruhe, Germany, Sept. 1983.

Associated Grants and Contracts

1. Joseph Flynn and Emanuel Horowitz - The Johns Hopkins University, "Thermal

and Material Transport and the Solubility of Oxygen and Other Gases in

Oxidizing Polymer."

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 Flaming Conditions."

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

University, "Flow Field Effects on the Sooting Structure of Diffusion

Flames.

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

5. Eric M. Suuberg - Brown University, "A Study of the Effects of Oxygen

Transport, and Temperature History on the Chemistry of Polyraethyl

Methacrylate and Cellulose Pyrolysis."

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

7. Richard A. Dobbins - Brown University, "Soot Dynamics in Flames."

13
FIRE GROWTH AND EXTINCTION

CENTER FOR FIRE RESEARCH

FY84

Professional Personnel

James Quintiere, Head

Howard Baum, Research Physicist

Dan Corley, Physicist

David Evans, Mechanical Engineer

Margaret Harkleroad, Physicist

Warren Hayes, Fire Protection Engineer

Randy Lawson, General Physical Scientist

James Milke , Fire Protection Engineer

Bernard McCaffrey, Mechanical Engineer

Alex Robertson, Senior Scientist

Ken Steckler, Physicist

Alex Calderas-Flores , Coop Student

Claire Carpentier, Guest Worker, URBAT (France)

Michel Cur tat, Guest Worker, CSTB (France)

Yuji Hasemi, Guest Worker, BRI (Japan)

Hiroshi Koseki, Guest Worker, FRI (Japan)

Matti Kokkala, Guest Worker, (Finland)

Anil Kulkarni, Summer Faculty, Penn. State

Hisahiro Takeda, Guest Worker, Univ. of Tokyo (Japan)

Program Objectives

Through research we aim to develop predictive methods to describe the

processes of growth and extinction related to natural fires and fire safety.

Scope

The work addresses the processes of fire growth and decay associated with

fires within structures and with free burning fires. It examines the overall

dynamics of fire growth and its suppression in order to identify and understand the significant underlying processes: ignition, flame spread, burning

rate, extinction, and the 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.

Introduction

In February 1984 the group expanded its scope to address suppression and

extinction by the addition of staff in that area. Also, the activity in

"zone" modeling was set apart in a newly created Compartment Fire Modeling

group. Several foreign guest workers have since come and gone, each making a distinct contribution to our efforts. Also we should acknowledge the

technical and clerical support of Bill Rinkinen, Henry Wheelock, Dorna

Williams, and Wanda Duff in.

14
Proj ects

1. Fire Generated Enclosure Phenomena

Progress continues to be made (in collaboration with the Center for Applied

Mathematics) on the computations of three-dimensional unsteady, inviscid,

buoyancy generated flows within enclosures. The ability to include vents at

the boundary and to address combustion phenomena are under development.

Although computations have been made for long horizontal and vertical ductenclosures, large-scale computer resources have limited our exploration of

this capability.

Previously derived experimental data on natural convection wall vent flows due

to enclosure fires have been analyzed with tw> contributions. The first shows

the accuracy of current "zone" vent-plume models relative to data on vent

flows. This study addressed the phenomena of wall flows and vent mixing

effects on the compartment flows. Also it demonstrated the accuracy of

predicting natural convection vent flow rates solely from temperature data.

The second analysis showed the relative constancy of the vent (orifice) flow

coefficient - 0.68 to 0.73. A theoretical potential flow solution predicts a value of 0.62 against the data, but the theory indicates a slow increase with

vent to room width ratio with a rapid rise to 1 at an aspect ratio of 1.

A formulation of a one-dimensional unsteady model of counter- current corridor

flows induced by a fire has been completed. This vrork complements external

experimental and theoretical elaboration on this class of problems.

In addition, a project to enhance a probabilistic fire growth model for naval

vessels with deterministic formulae is underway. The identification of a decoupled set of algebraic fire growth sub-models offers a useful methodology

without heavy computer demands.

"A Perspective on Compartment Fire Growth" by J. Quin tier e, Comb

.

Sci. and Technol. , 40, 1984.

"Finite Difference Calculations of Buoyant Convection in an Enclosure, I. The Basic Algorithm" by H. R. Baum, R. G. Rehm,

P. D. Barnett, D. M. Corley, S.I.A.M. J. Sci. Stat. Comp. 4, p. 117,

(1983).

"Accuracy of Finite Difference Methods in Recirculating Flows" by

R. A. Beier, J. deRis, H. R. Baum, Numer. Heat Transfer 6, p. 283,

(1983).

"Calculations of Three-Dimensional Buoyant Plumes in Enclosures" by

H. R. Baum, R. G. Rehm, Comb. Sci. and Technol. , 40 , p. 35, (1984).

"Finite Difference Solutions for Internal Waves in Enclosures" by

H. R. Baum, R. G. Rehm, S.I.A.M. J. Sci. Stat, Comp., 5, (1984).

"An Investigation of the Forced Ventilation in Container shi p Itolds"

by H. R. Baum, J. A. Rockett, J. Fluid Mech., 142, p. 309, (1984).

15
"An Assessment of Fire Induced Flows in Compartments" by

J. G. Quint iere, K. Steckler, D. Corley, Fire Sci . and Technol. , ^|_,

No. 1, 1984.

"Fire Induced Flows Through Room Openings - Flow Coefficients" by

K. D. Steckler, H. R. Baum, J. G. Quintiere, NBSIR 83-2801 , 20th

Int. Symp . on Combustion (to be pub. 1985).

"Numerical Computation of 3 -Dimensional Fire Induced Flows and Smoke

Coagulation", R. G. Rehm and H. R. Baum, Ninth Int. Conf. on Numerical Methods in Fluid Dynamics (to be published 1985).

"Prediction of Corridor Smoke Filling Models" by W. W. Jones,

J. G. Quintiere, Comb. Sci. and Technol. , 35 , 1984.

"Air Flows Induced by Sparse Clouds of Droplets" by D. S. Bright,

R. A. Fletcher, H. R. Baum, Aerosol Science and Technology , _3, p.

187, (1984).

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

NBSIR 84-2841, May 1984.

2. Flame Spread on Materials

From data taken with a radiant panel apparatus , observations of ignition and

lateral flame spread on a vertically oriented material have led to a practical

procedure for determining general property data. Relying on a known relationship for the surface heat loss and heat transfer theories for ignition and

flame spread, the following effective properties can be determined.

kpc ~ product of conductivity, density, specific heat

T. ~ ignition temperature

T

°

s ,m ~ minimum temperature required for spread

$ ~ flame heat transfer parameter so that for ignition by thermal

radiation (q") under natural convection cooling, the time to ignite is

t ~ (kpc) [(T

ig - T.)/q^] 2

and for opposed flow spread velocity under natural convection

$

V = = , T > T

kpc(T. - T ) 2 S S » ig s

for a specified surface temperature T

g

. Over forty materials have been

successfully analyzed.

Progress to develop a counterpart procedure for upward flame spread has also

been made. The basic premise here is that the spread velocity can be derived

from an expression of the form:

16
V

q

6

,

kpc(T. - T )

ig s

where q" is the flame heat flux and 6^ is the flame extinction length beyond

the pyrolysis zone. In general the numerator parameters are not constant:

both vary with position and time. From static experiments on a vertical heat

transfer surface (2.5 m) wall slabs and line burner sources (Y. Hasemi) have

yielded total heat flux distributions which can be roughly correlated for all cases into a function only of position normalized with the flame length

measured from the base of the test sample. Although radiation and convection

have not been separated, the total maximum heat flux is generally found to be

between 2 to 3 W/ cm

2 in the flame zone and in accordance with the data of

Ahmad and Faeth overall. Current measurements are attempting to determine the

radiative and convective components.

Dynamic experiments of upward flame spread have been conducted (K. Saito) for

PMMA and wood samples. The effect of sample width, height and the ignition

energy supplied by a line burner source were studied. Surface temperature

measurements, along with a parallel radiative piloted ignition study, have

been used to define an ignition temperature to define the pyrolysis front and

its speed. Although bubbles are observed in the PMMA near 290 °C, ignition

appears to occur near 360 °C. For wood, interpretations are more difficult and

propagation could not be sustained for our conditions. Analysis and theoretical approaches are in progress.

More work in this area is planned and a study of fire plume ignition of a ceiling surface will be initiated.

"New Concepts for Measuring Flame Spread Properties" by

J. G. Quintiere, M. Harkleroad, ASTM/ SFPE Symp. on Appl. of Fire

Sci. to Fire Eng., Denver, June 1984 (ASTM STP to be published).

"Some Factors Influencing Fire Spread Over Room Linings and in the

ASTM E-84 Tunnel Test" by J. Quintiere, Fire and Materials , to be

published

.

"Wall Flames and Implications for Upward Flame Spread" by

J. Quintiere, M. Harkleroad, Y. Hasemi (in review).

"Heat Feedback and Flame Height Measurements on Burning Vertical

Surfaces" by A. Kulkarni, M. Harkleroad and J. Quintiere, Fall

Technical Meeting, Eastern Section, The Comb. Inst., (1983).

3. Dynamics of Compartment Wall Fires

This project has concentrated on an experimental study of the burning of a wall slab of PMMA in a 1 m scale enclosure. A technique has been developed to

monitor the mass loss of the PMMA over the fire development phase to "flashover." Instrumentation is used to monitor gas temperatures, wall convective

and radiative heat flux, and oxygen concentration. Other more extensive gas

analysis equipment has been assembled for more complete measurements subsequently. The objectives of the current experiments are to record the FMMA mass loss rate as a function of the changing compartment conditions, and then

17
to investigate the capability of existing theoretical models to predict the mass loss rate. This problem, devoid of surface flane spread, is a first step

at developing a sound predictive strategy for wall lining materials. A

parallel effort is underway to incorporate a complete wall fire growth model

into the "Harvard Compartment Fire Code."

Related studies (H. Takeda) included a small scale (1/3 m- sc ale) compartment

fire experiment in which floor slabs of PMMA were burned. An unusual feature

of these experiments showed pulsations in the burning behavior for particular

conditions and subsequent extinction in some cases.

Another study, sponsored by the Federal Aviation Administration, involved the

assessment of aircraft cabin lining materials subject to post-crash fire

conditions. This was a coordinated effort with other groups. It combined the

quantitative interpretation of full-scale experiments, an attempt to predict

ceiling ignition in this scenario, and an extensive series of measurements on

six candidate aircraft panel materials in several flammability apparatuses.

"The Role of Aircraft Panel Materials in Cabin Fires as Their

Properties" by J. G. Quintiere (ed) , V. Babrauskas, L. Cooper,

M. Harkleroad, A. Tewarson, FAA Report in review.

"Some Aspects of FLashover and Pre-Flashover Behavior in Compartment

Wall Fires" by H. Takeda, Fall Technical Meeting, Eastern Section,

The Combustion Institute, (1983).

4. Suppression Dynamics

This project area extends from the former Suppression and Extinguishment

Group. Our initial concerns have been with research on the extinguishment of

oil-well blow-out fires for the Minerals Management Service of Dol, and a new

experimental investigation of fully-developed compartment fire suppression by

idealized fire fighting water applications. In the former study several

experimental scales and water injection techniques for high speed fuel jets

have been examined. The most dramatic results demonstrated that suppression

of 5 to 10 MW gas jet flames was feasible with a 50 per cent decrease in flame

radiation and complete extinction of water to gas flow rate ratios greater

than 2 (or about 10 gal. of water was required).

The latter study of compartment fires is currently underway and utilizes vrood

crib fires and horizontal water sprays of various flows and drop size

distributions. The goal is to better understand and possibly predict fire

fighting tactics.

"Thermal Activation of Extinguishing Systems" by D. D. Evans, Comb.

Sci. and Technol. , 40 , p. 79, (1984).

"Suppressing of Gas Well Blowout Fires Using Water Sprays: Large

and Small Scale Studies" by D. D. Evans, D. Pfenning, American

Petroleum Institute, Fire and Safety Protection Meeting, San

Antonio, September 11-13, 1984.

18
"Control of Blowout Fires with Water Sprays", by D. Evans and

B. McCaffrey, Technology Assessment and Research Program for

Offshore Minerals Operations, OCS Report MMS 84 -0001, (1984).

"Jet Diffusion Flame Suppression Using Water Sprays" by

B. J. McCaffrey, NBSIR 84 -2812, also in Comb. Sci . and Technol , , 40,

(1984)

.

Grant Research

1. Fire Dynamics - flame radiation and pool fires, R. Friedman, PMRC.

2. Wind-Aided Flame Spread, A. C. Fernandez -Pello, U.C.B.

3. Theory of Flamespread with Charring, F. Fend el 1 , TRW and G. Carrier,

Harvard .

4. Upward Laminar Flame Spread Limits, J. Tien, Case-Western Reserve.

5. Turbulent Combustion, G. M. Faeth, Penn. St.

6. Stratified Combustion and Mixing, E. E. Zukoski , Cal. Tech.

7. Wall Burning in a Stratified Atmosphere, A. Kulkarni, Penn. St.

8. Drop-size Distribution in Sprays, J. Prahl , Case-Western Reserve.

9. Spray-Plume Interactions, R. Alpert, FMRC.

10.

Residential Sprinklers, H. C. Rung, JMRC.

19
FIRE PERFORMANCE AND VALIDATION

FIRE MEASUREMENT AND RESEARCH DIVISION

CENTER FOR FIRE RESEARCH

FY 84

Professional Personnel

Sanford Davis, Head

Billy T. Lee, Fire Prevention Engineer

Richard D. Peacock, Chemical Engineer

J. Samuel Steel, Physicist

J. Newton Breese , Computer Programmer

Program Objectives

The objectives are to develop the generic methodology for assessing the

accuracy and limitations of fire models and measurement methods and to design

and conduct tests to evaluate the fire performance of components, systems,

and structures.

Scope

This work includes two important efforts: first, the conduct of unique,

highly instrumented experiments to establish fire behavior on a realistic

scale in order to contribute to model development and second, the evaluation

and validation of fire models by providing expertise in facility fire test

experimental design, instrumentation, and data processing and analysis.

Proj ects

1. Validation of Fire Models

The fire model validation project, initiated in FY 83, moved into high gear

during the past year. One of the primary subtasks of the toxic hazard

assessment project has involved the development of efficient and accurate

models to predict the spread of smoke and gases in a building. Because the

smoke transport model was well advanced in its development, it was chosen as the first major effort of the validation project.

A room/corridor facility was constructed and instrumented for carrying out

full-scale experiments designed to evaluate the model. Replicate experiments were carried out using an idealized fire (gas diffusion burner) in which

several of the model input parameters were varied. Jointly with the Center

for Applied Mathematics, analysis and presentation of the data have been

under development. Although this work has been associated with a specific

model, the development of the generic methodology for model evaluation has

been started and will be refined during the coming year.

In order to further support the toxic hazard assessment project, the

program for the coming year will include the study of "real" fuels. This

will enable us to test the model for growing fires, as well as to evaluate

20
the N-gas model for toxic effect of combustion products. A target room

has been instrumented for gas analysis and for animal exposure experiments. In addition to the study of horizontal smoke movement, work will

be initiated to evaluate the model for predictions of smoke transport in

a vertical mode between floors in a two-story residential type facility.

2. Large-Scale Fire Test Facilities Development

An existing two story fire test facility in the large-scale fire re- search laboratory is being modified to simulate the interior of a residential townhouse. This structure, exclusive of kitchen and bathroom

facilities, will be typical of the smaller townhouses being built in the

1980's. The main features of this modification are to provide an open

stairway connecting the two levels and an external exhaust collection

system for measuring rate of energy release.

A new computer based data acquisition system is being installed in the

full scale fire test facilities that will dramatically increase our data

collection capabilities. The new system will double the data collection

rate currently available and increase the number of channels that can be

dedicated to a single test. Two computers, two hard disk drives, a full

color interactive graphics display, and the data collection equipment

form the nucleus of the system.

In addition to the improved data collection capabilities, an interactive

color graphics display is included in the system that will allow display

of test data and calculations based on test data while the test is

underway.

The burn room and room/corridor test facilities at Building 205 are

located adjacent to an exhaust hood which collects the combustion products from fire tests conducted in these facilities. The hood has been

instrumented to measure heat, smoke, and combustion products from these

tests as a function of time. The burn room can be used to quantify the

fire hazard contribution from interior finish and furnishing materials.

It has been used to analyze the thermal environment in the room for

various ignition exposures and fuel loadings, to study flame spread on room surfaces, and to evaluate the room effect on burning furnishings.

The room/corridor test facility permits measurement of the fire environment along the corridor and in adjoining side rooms as a function of

fires of various types and intensities in the test room.

Reconstruction of the NBS furniture calorimeter is complete, resulting

in improved instrumentation, control, and methods for data collection

and reduction. Mass flow rate through the system was doubled, and a variable speed exhaust fan allows improved measurement sensitivity by

providing variable mass flow rates. Each of these improvements results

in better control and more accurate data.

3. Flame Spread on Walls

The objective of this project is to study fire spread and growth Involving wall and ceiling finish materials when exposed to different

21
ignition scenario and to 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. Another

objective is to use the data from these studies to help further develop

the standard room fire test for use by ASTM.

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 either lines the walls or the ceiling

or fully lines both walls and ceiling. For some materials, the surface

fire spread rate was found to be a strong function of the ignition

exposures considered. Heat transfer characteristics and fire spread

from full-scale plume impingement of ceiling finish materials will be

performed next. A study on flame spread along a single wall surface

using a line burner ignition source will also be conducted to obtain a more detailed understanding of the phenomenon.

Lee, B. T. Standard Room Fire Test Development at the National Bureau

of Standards, ASTM/SFPE Symposium on Application of Fire Science to Fire

Engineering, Denver, CO, June 26 and 27, 1984.

4. Fire Safety Aspects of Solid Fuels

The objective of this continuing 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

small scale applications. The overall research program included the

evaluation of a number of different protection systems designed to

shield combustible wall and ceiling surfaces from the effects of radiant

energy from hot stove and chimney connector surfaces. Acceptable systems will be those found capable of maintaining the surface temperatures

of walls and ceilings at or below code recommended temperature rise

limitations throughout the exposure period. Another aspect of the

program included the evaluation of a number of different types of

thimbles or wall pass-through systems which will, in effect, help maintain the surface temperature of combustibles in the walls within code

acceptable temperature rise limitations throughout the exposure.

Loftus, J. J. and Peacock, R. D. , An Evaluation of Wall Protection

Systems for Wood Burning Appliances, Fire Journal, September 1983.

Loftus, J. J. and Peacock, R. D., Clearances and Methods of Protection

for Wall and Ceiling Surfaces Exposed to Radiant Heating Appliances,

Nat. Bur. Stand. NBSIR in preparation.

Loftus, J. J. and Peacock, R. D., Evaluation of Thimble-Chimney Connector,

Wall Pass Through Systems for Solid Fuel Heating Appliances, Nat. Bur.

Stand. NBSIR in preparation.

22
5. Fire Performance of Walk-On Platforms of the VA Hospital Building System

The objective of this project is to develop and evaluate test data on the

fire performance of unique construction systems proposed for use in VA

medical facilities. The building concept incorporates a suspended walk-on

deck system which forms an interstitial space between functional floors.

These systems are designed to provide a fire endurance of two hours between

functional floors when exposed to a heat environment which follows the

ASTM E119 time-temperature curve. Tests were conducted in a three level

steel frame structure which represents a portion of a mid-rise building. Two

different suspended walk-on deck systems were constructed in the test structure and evaluated. More than 130 thermocouples throughout the structure

measured temperature rise on critical building components. Deflection

measurements were made on the walk-on deck systems.

A computer model was used to simulate fire performance of the walk-on deck

systems and results were compared with test data. This was done to further

validate the computer model. Computer model predictions were typically

within 15 percent of actual test values. The test data showed that both

walk-on deck systems performed well during the two hour fire exposures. It

also showed that fireproofing on structural steel members can be of major

importance.

Lawson, J. R. , Fire Performance of Interstitial Space Construction Systems,

Nat. Bur. Stands., NBSIR in preparation.

6. Fire Safety of Amtrak Passenger Car Interior Furnishings

A series of fire tests was conducted to assess the burning behavior of the

interior of passenger rail vehicles. Three types of tests were performed:

(1) small-scale laboratory tests to study the flammability and smoke generation characteristics of the individual materials, (2) full-scale calorimeter

tests on the seats to determine the rate of heat release from burning seat

assemblies, and (3) full-scale tests on mock-ups of the interior of the cars

to investigate the potential for fire hazard in the fully furnished vehicles.

A comparison of the results of the selected small-scale laboratory tests with

the full-scale mock-up tests shows that while the small-scale tests can be

used to screen individual materials, the geometry of the full-scale mock-up

tests are critically important in predicting the potential for fire inside

the vehicle.

Peacock, R. D. and Braun, E. , Fire Tests of Amtrak Passenger Rail Vehicle

Interiors, Nat. Bur. Stands., NBS Technical Note 1193, May 1984.

23
Fire Safety Performance

Center for Fire Research

FY 84

Professional Personnel

Harold E. Nelson, Head

Bernard M. Levin, Research Psychologist

Edward K. Budnick, Research Fire Protection Engineer

A. Jeffrey Shibe, Research Protection Engineer

S. Wayne Stiefel, Operations Research Analyst

W. Douglas Walton, Research Fire Protection Engineer

Eric Rosenbaum, Coop Student-Fire Protection Engineer

Steven Thorne, Coop Student-Fire Protection Engineer

Steven Baer, Coop Student-Fire Protection Engineer

Program Objectives

The objectives of the Fire Safety Performance thrust encompass the development

of a system of methods for use in predicting the performance of facilities

and people in response to the potential fire threats.

Scope

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 judgment. It involves development of

a framework of macro models and other systems for 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. It also

addresses factors related to the likelihood of fire incidents, the varibility of

parameters, and quantitative measurement of fire risk.

Project Areas

1 . Engineering Methodologies for Predicting Facility Fire Safety

Development of systems of deterministic models and procedures for predicting

the performance of facilities, the response of fire protection systems, the

ability of occupants to cope, and the resultant impact in case of fire. Tasks

will include the assembly, development and combination of existing, emerging

and new systems, models, and other computational approaches that can be incorporated into design and/or hazard evaluation systems for use by fire protection

engineers and others. Extensive use will be made of the outputs (e.g. models)

of other CFR thrusts. The approach is to develop an overall integration

"model" workable at various levels of sophistication; obtain or develop the

24
necessary sub-routines; merge and adopt these, as appropriate, to obtain

the problem solving methods; and establish confidence guidance on its use. Currently the project is addressing computational means to:

a. Estimate hazard growth in rooms and corridors.

b. Predict performance of fire protection devices.

c. Calculate horizontal and vertical perimeter smoke leakage.

d. Evaluate agreement of above with test results.

e. Appraise the evacuation time required.

f. Develop a model of human behavior, decisions, actions in flux.

2 . Fire Risk Measurement Methodologies

Continued development of methods for the quantitative measurement of fire

risk — the probability and magnitude of fire caused harm to life, property,

or operational capabilities. The overall risk measurement structure developed

for the residential setting in FY 84 is being used to integrate probabilistic

functions into both the key variables of the emerging deterministic models

and the choice and weighting of individual simulations executed by those models.

The risk measurement form of the models will apply the deterministic models in

the stochastic environment of reality to predict the likelihood of selected

types of harmful impact (e.g., death, injury, property loss) of a given entity

(e.g., building, operation, use) and the change in this likelihood caused by

selected mitigation measure implementation. The development of the structure

will require attention to each element within the overall model (e.g. , ignition,

spread, growth, human reaction, tolerances, damageabilities , etc.). The inclusion of stochastic considerations will require the development of a process

for assigning values to critical variables according to fire scenario and a process for weighting each scenario. This process may involve Monte Carlo

techniques

.

3 . Engineering Methods for Calculating Thermal Activation

Development of generalized method for determining response of thermally

activated devices to typical growing compartment fires; output in form

satisfactory for engineering problem solving (eg. microcomputers, hand

calculators, charts & tables).

Candidate methods for detector spacing and sprinkler activation have been

under development. Current versions include limited geometry and fire

growth effects. A benchmark tested, generalized model is necessary in

order to address variations in design problems.

A comparative analysis of current methods will be performed to identify

limitations, and assess accuracy of the calculation methods. Based on this

analysis and experimental data, a candidate method will be developed,

extending the scope of the existing methods to include localized conditions

appropriate for sidewall sprinkler and ceiling locations in adjacent spaces.

The accuracy of these modifications will be assessed based on experimental

work by Evans, and from data collected under the Kung grant at FMRC. Where

demonstrated feasible, methods will be generalized and put in user friendly

format

.

25
4.

Aircraft Fire Risk

Development and exercise of a risk assessement modeling approach for aircraft cabin fire safety analysis. Continued risk assessment development

efforts with special emphasis on in-flight fires and evaluation of multiple

mitigation strategies —involving fire prevention, earlier detection, smoke

control, fire spread limitation, or improved suppression. The approach will

require enlargement of the data base of historical fires to include non- fatal fires; development of a generic structure capable of determining the

risk (for different classes of fire scenario (e.g. concealed space fire,

gasoline fires, etc.)) associated with multiple mitigation strategies;

exercise of the methods on a selected sample of strategies to demonstrate the

application of the methods, and refinement of the generic cost model developed

in the first phase effort to specify the cost parameters in sufficient detail

to permit data collection.

5

.

Pragmatic Fire Safety Evaluation

To develop grading systems needed by various agencies to judge the hazard

of facilities and the impact of parametric changes.

Complete development of the FSES's for Board and Care Homes, NASA Operations

Buildings, and Detention and Correctional Occupancies. The major work yet

to be accomplished relates to the evaluation systems for coal mines and

operations buildings.

Associated Grants and Agreements

1. Factory Mutual Research Corporation, Gunnar Heskestad, Experimental Fire

and Smoke Verification Data for Multi-room and Corridor Conditions.

2. University of Washington, John Keating, Post Fire Interviews: Development

and Field Validation.

3. AIA Research Corporation, Earle Kennett and Daniel Alvord, Fire Safety

Evaluation System for Board and Care Homes (Escape and Rescue Model)

.

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

Emergency Planning and Training Manual for National Park Residential Buildings.

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

Building Evacuation: Development of Software System.

6. SRI International, Fred L. Offensend, Continuation of Decision Analysis

Studies in Fire Hazard Analysis.

7. Center for Applied Mathematics, National Bureau of Standards, Economic

Analysis of Residential Automatic Sprinkler Systems.

8. University of Maryland, Kwan-nan Yeh (IPA) , Ignition Risk Analysis.

26
Publications and Other Products

Budnick, E.K., Estimating Effectiveness of State-of-the-Art Detectors and

Automatic Sprinklers on Life Safety in Residential Occupancies, National

Bureau of Standards Report NBSIR 84-2819 (1984)

.

Nelson, H.E., Credible Engineering Methodologies (as a solution to bridging

the fire safety technology gap). Conference on communications between the

fire research community and the owner-operators of buildings. Session on "Possible ways of bridging the communications gap" November 10, 1983,

Washington, D.C.

Nelson, H.E., How close are we to scientifically based fire protection

engineering? IFPEL - IV International Fire Protection Engineering Institute;

February 26-March 10, 1983: Brunnen, Switzerland.

Alvord, D.M., Escape and Rescue Model: A simulation model for the emergency

evacuation of board and care homes. National Bureau of Standards Report

NBS-GCR-83-453 (1983)

.

Alvord, D.M. , Status report of Escape and Rescue model; National Bureau of

Standards Report NBS-GCR-83-432 (1983)

.

Kahn, M.J. , Detection times to fire-related stimuli by sleeping subjects.

National Bureau of Standards Report NBS-GCR-83-435 (1983)

.

Nober, E.H. , Peirce, H. , Wells, A., Waking effectiveness of household smoke

and fire detection devices, National Bureau of Standards Report NBS-GCR83-439(1983)

.

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

Investigations in Ten Cities; Final Report; National Bureau of Standards

Report NBSIR 83-2803(1983).

Hall, Jr., J.R. and Helzer, S.G., Civilian Residential Fire Fatality Rates:

Six High-Rate Versus Six Low-Rate States, National Bureau of Standards

Report NBSIR 83-2754 (1983).

Hall, Jr., J.R. and Stiefel, S.W., Decision Analysis Model for PassengerAircraft Fire Safety with Application to Fire-Blocking of Seats, National

Bureau of Standards Report NBSIR 84-2817(1984).

Kisco, T.M. , Francis, R.L., Network Models of Building Evacuation: Development of Software System. National Bureau of Standards Report NBS-GCR-84-457

.

Chapman, R.E., Hall, W.G., User’s Manual for the Fire Safety Evaluation System

Cost Minimizer Computer Program. National Bureau of Standards Report NBSIR

83-2797.

Nelson, H.E., Shibe, A.J., Levin, B.M. and Thorne, S.D., Cooper, L.Y., Fire

Safety Evaluation System for National Park Service Overnight Accommodations,

NBS Report No. NBSIR 84-2896.

27
FIRE TOXICOLOGY

FIRE MEASUREMENT AND RESEARCH DIVISION

CENTER FOR FIRE RESEARCH

FY84

Professional Personnel

Barbara C. Levin, Research Biologist and Head

Laura L. Baier, Biologist

Cheryl S. Bailey, Research Chemist

Emil Braun, Physicist

Steven E. Harris, Guest Worker, University of Pittsburgh

Joshua L. Gurman, Research Associate, American Iron and Steel Institute

Maya Paabo, Research Chemist

Program Objectives

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.

Proj ects

1. Toxicity Measurement Method Development

The Center for Fire Research has developed a test method to assess the acute

inhalation toxicity of combustion products from materials thermally decomposed

under specific laboratory conditions. Although this test screens materials

under presumed worst case (but still realistic) flaming and non-flaming

conditions, it does not subject materials to all fire conditions. The objective

of this study is to determine the extent to which the toxicity of a material’s

combustion products is sensitive to changes in combustion conditions. Therefore, a new combustion system has been designed, a modification of the cone calorimeter developed by the Center for Fire Research to measure the rate

of heat release. This new radiant energy system will permit the evaluation of

materials under a variety of combustion conditions and measure the effects of

these conditions on toxicity. For example, early smoldering conditions will

be simulated by exposing the materials to low radiant fluxes and high oxygen

concentrations; preflashover conditions will be simulated by using higher

radiant fluxes and oxygen concentrations greater than 16%; and flashover

conditions will be examined by using high radiant fluxes and very low

oxygen concentrations. Materials will also be tested in both vertical

and horizontal orientations, and the surface of composite materials

normally exposed to the fire will be exposed to the heat source first.

In addition, the new system is designed to provide continuous mass loss

measurements and to allow square wave exposures of the animals.

28
Levin, B. C. , Paabo, M. , 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," National Bureau of

Standards, Washington, DC, NBSIR 83-2678, 1983. 88p.

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

Proceedings of the Flame Retardant Chemical Association Meeting, 1983,

Baltimore, Maryland. In press.

Gann, R. G. , "Predicting Fire Hazard," Proceedings of the National Conference

on Fire Toxicity, sponsored by the Consumer Product Safety Commission and the

National Aeronautics and Space Administration, Arlington, VA, June 26, 1984.

2. Determination of the Toxicological Effects of Fire Gases, Alone and In

Various Combinations for Use in Toxic Hazard Assessment Computer Models.

Experimental research is being conducted to characterize the toxic, gases

produced in fires and their specific effects on living organisms. The two

main purposes of these studies are: (1) to accumulate baseline data to determine

the extent to which the toxicity of a material's combustion products can be

explained by the interactions of the major gases produced in fires or if it is

necessary to account for the minor and more obscure thermal decomposition

products; and (2) to predict the toxicological effects of combinations of fire

gases on humans for use in the computer modeling of toxic hazard.

To date, LC,.q values have been determined for carbon monoxide (CO) in air for

10, 20, 30 and 60 minute, experiments using rats exposed in the bead-only mode

in the chamber designed for use in the NBS Toxicity Test Method (NBSIR 82-2532).

Similar LC-.. values have been obtained for hydrogen cyanide (HCN) in air.

Thirty minute experiments on the effect of combinations of CO and HCN in air

have shown that these two gases appear to act in an additive manner such that

if

[CO] [HCN]

LSo co

(30 min) LC

50

HCN

> 1

(30 min)

the animals will die. If the above equation is lower than 1, the animals

will live.

Carbon dioxide (C0~) is relatively non-toxic. Yet, in 30 minute experiments,

sublethal levels or CO in combination with sublethal levels of CO caused

deaths of the rats. The most toxic combination of these two gases was found

to be 5% CO

2 and 2500 ppm CO. Experiments have also been conducted with

reduced oxygen (0^) concentrations. The 30 minute LC_„ value is 7.5% 0^. As

expected, the toxicity of the exposures increased as tne animals inhaled com- binations of additional toxic gases, e.g., low 0^ and C0 o or low CO and

C0„. Preliminary examination of the toxic gases evolved '"'from some materials

indicates that the interactions of the primary toxic gases, CO, CO^ and HCN,

appear to explain the toxicity of the combustion products.

Levin, B. C., Paabo, M., Bailey, C. S., Harris, S. E. and Gurman, J. L.,

"Toxicological Interactions of the Primary Gases Produced in Fires."

Manuscript, in preparation.

29
Fowell, A. J., "An Approach to Hazard Assessment of the Combustion Products

in Building Fires." Proceedings of the 4th International Fire Protection

Engineering Institute, Switzerland, 1984.

3. Conditions Conducive to Hydrogen Cyanide Generation From Flexible Polyurethane Foam (GM-21)

.

In Fiscal Year 1983, we identified a set of combustion conditions under which

increased concentrations of hydrogen cyanide (HCN) are generated from flexible

polyurethane foam. A two-stage decomposition process is necessary. First,

the flexible polyurethane foam is heated at a relatively low temperature

(25°C below its autoignition temperature) and a char is formed. In the second

step, this char is heated to higher temperatures (approximately 500-600°C)

,

during which approximately ten times more HCN is produced than when the virgin

foam is thermally decomposed in a single step process regardless of temperature

or whether the materia.l is in a non-flaming or flaming mode. The two-stage

decomposition simulates a real fire scenario in which a cigarette dropped in

a crevice of a polyurethane chair causes the chair to smolder for some un- defined period of time during which a char is formed. At some point the chair

will burst into flames, heating the char and releasing the cyanide. Validation

studies with polyurethane chairs have shown that significant quantities of

cyanide are generated at the time that the chairs burst into flames.

In Fiscal Year 1984, much effort was expended to determine the molecular

mechanisms for the increased cyanide production from this two step decomposition process. We found that the HCN levels were related to the amount of

char formed. A fire retarded polyurethane foam (GM-24) produced twice as much

char and twice as much HCN as the non-fire retarded foam (GM-21) even though

elemental analysis of the two chars indicated that both contained the same amount of nitrogen.

Ion chromatographic analysis of both basic, and acidic extracts of the chars

showed very little HCN indicating that cyanide was not physically adsorbed

to the char, but more likely was produced by the thermal degradation of a nitrogen-containing compound. That this compound is probably highly crosslinked and insoluble was indicated from elemental analysis studies showing

that the nitrogen content of the chars was not reduced after extraction with

a variety of organic solvents.

Additional analysis by ESCA (electron spectroscopy for chemical analysis),

FTIR (Fourier transform infrared), pyrolysis/mass spectrometry, and u solid-state NMR (nuclear magnetic resonance) provided little additional

information as to the molecular structure of the nitrogen-containing compounds.

These results did provide evidence that the charred residues contained more

than one nitrogen-containing compound and suggested the presence of amine,

amide, imine, and nitrile functional groups.

For these studies, we acknowledge the help of W. F. Koch, T. J. Jack, J.

Strassburger , K. J. Voorhees, and W. Manders.

Levin, B. C. , Paabo, M. , Fultz, M. L. , and Bailey, C., "Conditions Conducive

to the Generation of Hydrogen Cyanide from Flexible Polyurethane Foam."

Proceedings of the 7th Joint Meeting of the U.S. -Japan Panel on Fire Research

and Safety, UJNR, National Bureau of Standards, Washington, D. C., October

1983. In press.

30
Levin, B. C., Paabo, M. , Fultz, M. L. Bailey, C., Yin, W., and Harris, S. E.

,

"An Acute Inhalation Toxicological Evaluation of Combustion Products from

Fire Retarded and Non-Fire Retarded Flexible Polyurethane Foam and Polyester."

National Bureau of Standards, Washington, D.C., NBSIR 83-2791, November, 1983.

70 p.

4. An Acute Inhalation Toxicological Evaluation of Combustion Products From

Fire Retarded and Non-Fire Retarded Flexible Polyurethane Foam and

Polyester

.

The acute inhalation toxicity of the combustion products from selected

upholstered furniture filling materials with and without fire retardants

was evaluated by the NBS toxicity test method (NBSIR 82-2532). The five

materials that were evaluated consisted of two different formulations of

flexible polyurethane foam (each formulation was supplied in both a fire

retarded and non-fire retarded form) and a polyester fiberfill (not fire

retarded). Atmospheric concentrations of carbon monoxide, carbon dioxide,

oxygen, and hydrogen cyanide in the exposure chamber were monitored throughout the thermal decomposition of the materials. In addition, time-toignition, rate of heat release, hydrogen cyanide generation via a two step

decomposition procedure and x-ray fluorescense measurements were performed.

The LC[- n (30 minute and 14 day) values did not distinguish any of the

materials as being significantly more toxic than the others. In the worst

case, one of the fire retarded polyurethane foams was only a factor of two

more toxic than its untreated counterpart. Only the fire retarded foams and

the polyester caused deaths of the Fischer 344 rats during the 30 minute

exposures. Extensive weight loss and post-exposure deaths occurred after

exposure to the combustion products from all the materials. Animal deaths

during or following exposure to the polyurethane cannot be attributed to

carbon monoxide or hydrogen cyanide alone. Deaths during exposure to the

polyester combustion products appear to be more directly related to the con- centrations of carbon monoxide.

Levin, B. C. , Paabo, M. , Fultz, M. L., Bailey, C., Yin, W. , and Harris, S. E.,

"An Acute Inhalation Toxicological Evaluation of Combustion Products From Fire

Retarded and Non-Fire Retarded Flexible Polyurethane Foam and Polyester."

National Bureau of Standards, Washington, D.C., NBSIR 83-2791, November,

1983. 70 p.

5. Measurement of NO^ During Large-Scale Room Fire Tests

The objective of this study was to determine whether significant concen- trations of NO are generated in large-scale fire tests from either nitrogencontaining materials or from atmospheric nitrogen fixation. In the latter

case, polystyrene, a material without nitrogen, was tested. The measurement

technique was based on the principle of chemiluminescence in which NO reacts

with 0^ and the photoemission of the excited NO^* is measured. A stainless

steel converter is used to reduce the N0

2 to NO so that all N0 ? generated in

the fire is detected and treated as NO. At high temperatures, the stainless

steel converter will also convert other nitrogen-containing compounds, such as HCN, NH^, acetonitrile, and phenylisocyanate , to NO. This interference thus

produces results which may be higher than the actual concentration levels of

the NO . x

31
Using this technique, the NO from a number of large-scale room tests has

been measured. Atmospheric nitrogen fixation appears to be of little concern

as the maximum concentration of NO observed from tests involving polystyrene (no nitrogen) was 25 ppm. In other tests involving polyisocyanurate

foam (containing nitrogen), a maximum of 60-110 ppm NO was detected after

accounting for HCN interference by separately measuring the HCN and subtracting that amount. The instrumental reading attributed to NO may still

be high due to the interference of some other unknown nitrogen containing

compound. These experimental studies are continuing.

6. Blood Cyanide Measurements

The objective of this project has been to review, assess, and improve

currently available procedures for measuring the concentration of cyanide in

blood. In addition, we also evaluated the handling and storage techniques

for blood to ensure both precision and accuracy of results. During the first

year of this study, Valentour's electron capture gas chromatographic analytical technique in conjunction with the Conway diffusion procedure for

separating the cyanide from the blood was used extensively. This system

has two major limitations. First, it requires large volumes of blood (1-2 ml)

and secondly, it is a very time consuming procedure requiring a minimum

of four hours for the diffusion step. The within and between sample variability was also higher than desired. The Naval Submarine Medical Research

Laboratory technique by R. M. Bell et^ a^. was also examined. Only slightly

faster than the Conway Diffusion technique, it required the same large

quantities of blood and showed poor reproducibility.

We are currently evaluating a new semi-automated head gas system which

looks very promising. The volume of blood required is approximately

0.25 ml and the time from sampling to final result is about 30 minutes.

Initial tests indicate good reproducibility. We also plan to investigate the

feasibility of a technique developed by the U.S. Army Medical Command Unit,

Aberdeen Proving Ground. They have loaned us some of the necessary equipment

and we are trying to obtain the other pieces. This system also has the

advantages of using small samples and requiring only 15 minutes from sampling

to final results.

7. Review of the Toxicology and Combustion Products from Ten Synthetic

Materials

A survey and a detailed critical review of the literature on the thermal decomposition products and inhalation toxicity of ten plastics commonly found

in residential homes are being done under contract for the Consumer Product

Safety Commission. The materials being examined are poly (vinyl chloride),

polystyrene, nylon, polyethylene, phenolics, acrylics, ABS, polypropylene,

polyester, and rigid polyurethane. The computer data bases that were searched

included Toxline, Medlars, RTECS, Environmental Abstracts, NTIS, TRIS,

Excerptica Medica, RAPRA and Chemical Abstracts. Over 1,000 pertinent

articles were identified and collected from the Fire Research Information

Services (FRIS) of the Center for Fire Research or through interlibrary loan.

The first three materials - rigid polyurethane foam, nylon, and polyester - are being reviewed at the present time.

32
Associated Grants

J. 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."

33
FURNISHINGS FLAMMABILITY

FIRE MEASUREMENT AND RESEARCH DIVISION

CENTER FOR FIRE RESEARCH

FY 84

Professional Personnel

Vytenis Babrauskas, Fire Protection Engineer, Head

John Krasny, Textile Technologist

Joseph Loftus, Research Chemist

Richard Dipert, Fire Protection Engineer

Program Objectives

The objectives are to develop and validate measurement methods and to generate data necessary to characterize the fire performance of furnishings

and other combustible occupant items.

Scope

Current understanding of building fires places a major emphasis on the burning properties of the combustibles involved, which are generally furniture

or other occupant combustibles. Both mathematical fire modeling and engineering applications require that flammability properties—heat release rates, mass loss rates, smoke and gas product production rates—and also ignition

and flame spread properties be known. The research necessary to develop

this data base falls into two categories: (1) full-scale burning behavior

studies of furniture items under realistic fire scenario conditions, and

(2) development of bench-scale laboratory tests suitable to the prediction

of the full-scale behavior. For maximum generality and validity the benchscale tests should not be arbitrary, but rather should be configured to

represent, as much as possible, physical or chemical properties of the materials being tested.

Projects

1 . Development of the cone calorimeter

During the past year two separate smoke measurement devices were implemented

on the cone calorimeter. An optical extinction beam was designed, using

a small He-Ne laser, which can be used to make direct readings of the extinction coefficient of the smoke. Also implemented was a soot mass gravimetric

sampling technique, whereby a flow stream proportional to the main exhaust

duct flow is sampled on filter discs. When validated, these cone calorimeterbased smoke measurements will allow the NBS smoke chamber to be obsoleted.

Also being implemented are real-time measurement capabilities for a number

of additional product gases, including HCl and HCN.

Significant progress was also made during the year in standardization activities. The working group on heat release rate in ISO selected the cone calorimeter for standardization. Within ASTM a first ballot was taken; also,

a new working group is being formed for cone calorimeter operators (laboratories) .

34
An investigation of the suitability of the use of the cone calorimeter for

predicting room flashover was made. For rooms with walls and ceilings lined

with a single, combustible lining type, it was found that flashover velocities could be predicted by the use of a function (peak heat release rate)/

(time to ignition), with both the measurements being made in the cone calorimeter.

Babrauskas, V., Development of the Cone Calorimeter—A Bench-scale Heat

Release Rate Apparatus Based on Oxygen Consumption, Fire & Materials. 8,

81-95 (1984).

2. Upholstered furniture burning rates

Based on data available to this point (furniture calorimeter burns of both

actual furniture and mockups), a unified engineering calculation scheme

was developed, allowing both the peak heat release rate to be predicted,

and release rate curve to be represented by the use of a triangular representation. The method allows various frame materials to be treated; however,

experimental data in this area are thin, and additional experimental work

is planned for next year.

Other activities included a cooperative program with the California State

Bureau of Home Furnishings, where NBS tested in the cone calorimeter specimens of institutional chairs which were burned in full-scale by the California State BHF. Also, a monograph was prepared, intended to serve as an engineering guide for the flammability design of upholstered furniture and

beds

.

The results of a validation testing program were published, which compared

the behavior of upholstered furniture burning rates in the furniture calorimeter and in room fires—pre-flashover and post-flashover—but not in the

ventilation-limited regime of post-flashover fires. The behavior was seen to be, to within experimental error, identical. Also examined were several

simplified theories for flashover prediction.

The data enabled the theory of P. H. Thomas to be identified as the most

useful.

Furniture and bed fires often involve pillow burning. Since there existed

no available data, experimental measurements were made in the furniture

calorimeter of a number of common pillow types.

Babrauskas, V., Upholstered Furniture Room Fires—Measurements, Comparison

with Furniture Calorimeter Data, and Flashover Predictions, J. of Fire Sciences. 2, 5-19 (1984).

3. Flame spread over furniture items

The role of flame spread over upholstered furniture items was further clarified by analysis of the mockup test data. This showed that a substantial

fraction of the variance in the full-scale (furniture calorimeter heat re- lease rate) vs. bench-scale (cone calorimeter data) could be accounted for

by flame spread differences. This is in contrast to ignitability measurements, whose effects were seen to be negligible.

35
Investigations in a special apparatus for the measurement of flame spread over upholstered furniture were made with calibration specimens and showed

a significant dependence on specimen width.

Dipert, R., Applications of Flame Spread Modeling to Flame Spread on Horizontal Samples. (M.S. Thesis). Worcester Polytechnic Institute (July 1984).

4. Protective Garments

A review was made summarizing both the flammability and the heat transfer

aspects of protective garments, for firefighters and other workers.

Krasny, J. F., Some Characteristics of Fabrics for Heat Protective Garments,

presented at the ASTM International Symp. on Protective Clothing (July 1984).

Associated Grants

1. Brown University, Merwin Sibulkin - Study of Effects of Material Properties on Flaming Combustion of Charring Fuels.

2. Factory Mutual, Archibald Tewarson - Development of a Model to Provide

Comprehensive Fire Property Data.

3. Stanford University, George Springer - The Behavior of Furniture Frames

during Fire.

4. University of Dayton Research Institute, Mark Dietenberger - Mathematical Modeling of Furniture Fires.

36
SMOKE HAZARD

FIRE SAFETY TECHNOLOGY DIVISION

CENTER FOR FIRE RESEARCH

FY 84

Professional Personnel

Richard W. Bukowski, Head

Dan Gross, Senior Research Engineer

Walter Jones, General Physical Scientist

John Klote, Mechanical Engineer

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 impacts particularly on people

in fire situations.

Scope

The predictive methods being developed are based on numerical modeling but,

also include hand calculation methods for estimating hazards and production

of design curves/tables for use by architects and engineers. To ensure use,

necessary data must be readily available and data input and presentation

must be in terms readily understandable by the average professional. Thus,

the projects include a strong emphasis on state-of-the-art computer graphics

and computer aided design techniques.

Proj ects

1. Toxic Hazard Assessment Methods

The predictive methods currently under development are being applied to the

evaluation of the hazards of combustion product toxicity relative to the

other hazards to occupants from fire, i.e. thermal, smoke obscuration. The

goal is to produce a model which can make hazard predictions for specific

fires (materials in their context of use) in specific, multi-story building-.

To date, a zone model which can produce predictions for multiple compartments on a single floor and spread to other floors through open shafts or openings in the ceilings (but not stairwells) has been produced. This model

can display its results on a color computer graphic system in a two

dimensional format using a color coded hazard display and histograms for

selected parameters. The model tracks temperature, smoke density, interface

heights, and eight individual gas species through all compartments.

Bukowski, R. , "Development of a Method for Assessing Toxic Hazard", to be

published in NFPA Fire Command.

Bukowski, R. , "NFPA Toxicity Advisory Committee Strawman Procedure for

Estimating Smoke Toxicity Hazard", to be published in proceedings of the

NFPA Toxicity Workshop.

37
Bukowski, R. , "Toxic Hazard Evaluation of Plenum Cables", to be published

in NFPA Fire Journal.

2. Smoke Transport Modeling

This work connects various modeling efforts in CFR. The model work itself

revolves around a robust zone model which can predict the transport of

smoke, species and fire from compartment to compartment in an arbitrary

structure. At one end it will use the fire models which are being developed

and at the other end provide output for building design consideration and

personnel evacuation models.

A great deal of effort has gone into fast, stable numerical routines and

data presentation that is ei|y to use. By retaining the conservation

equations in differential form we retain the ability to do the calculations

for pressurized systems, flame puffing and related phenomena.

Verification of this model is an ongoing process. The first comparisons

have been presented. Validation on both a laboratory scale, as well as full

scale, is particularly important if the model is to fulfill its two primary

goals, namely instituting a credible toxic hazard protocol and being able

to use laboratory scale experiments to check designs of full scale buildings

and ships.

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

Models", Combustion Science Technology 35^, 239 (1984).

Jones, W. , "A Model for the Transport of Fire, Smoke and Toxic Gases", to be

published in various forms in the Fire Safety Journal, as an ASTM Special

Publication, an NBSIR (Model Documentation and User’s Guide) and NTIS.

Bodant, X. and Jones, W. , "A Note on the Calculation of Gas Flows in

Buildings", to be published.

3. Computer Graphics

The purpose of this sub task is to support firstly the FAST model (previous

sub task) and secondly, other theory and experimental work. The thrust is to

provide input which can be utilized by the transport models and output which

is easily understood and assimulated. We are working with state-of-the-art

high resolution graphics display equipment and input devices. The goal is

to be able to show smoke spread in buildings in real time in a three

dimensional perspective animation.

Jones, W. and Fadell, A., "A Device Independent Graphics Kernel", to be

published as an NBSIR.

Associated Grants and Contracts

1. Craig Beyler - Harvard University, "Prediction of Upper Layer Composition

in Transient Compartment Fires."

38
2 . Edward Zukoski - Cal Tech, "Experimental Study of Environment and Heat

Transfer in a Room Fire."

3. Simon Goren - Univeristy of California, "Dynamics of Smoke and Inert

Tracers Produced in Porous Fuels."

4. Edward Wall - Federal Emergency Management Agency (FEMA) , "Major Fire

Investigations .

39
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution: American Institute of Architects

Grant No. : NB82NADA3043

Grant Title : A Computerized Model for the Simulation of General Fire

Emergency Evacuations

Principle Investigator : Mr. Daniel M. Alvord

American Institute of Architects Foundation

American Institute of Architects

Washington, D.C. 20006

NBS Scientific Officer : Mr. A. Jeffrey Shibe

Technical Abstract :

Obj ectives - The current objective of this project is to create a model that will investigate fire related emergency evacuation of com- monly encountered types of buildings. This tool can be used as an aid

in designing new buildings to decrease egress times in fire emergencies.

It may also be employed to find "optimum" egress paths for existing

buildings under various situations.

Approach and Future Plans - Discrete event deterministic simulation programs, either newly written programs or expanded versions of

existing programs, will implement the model. Networks consisting of

nodes and connections between nodes will represent the rooms, doors,

halls, and stairs of a building together with the permissible travel

paths between them. Congestion will be addressed by a separate mechanism. A fire simulation will eventually be linked to the model. Model

output will appear in graphic format as well as the current numeric

format. Finally, optimization capabilities will be investigated to

enhance the model’s versatility.

Progress to Date - Two simulation programs have already been written but lack many of the features discussed in the above section.

The first one, the Escape and Rescue Model, is a discrete-event

simulation program written in SIMSCRIPT II. 5, a simulation language.

It was developed to model the emergency movement involved in escape

and/or rescue of people from a board and care home housing a group of

persons with varying degrees of physical or mental disabilities, along

with a small live-in staff. It may also be used to model more general

types of small structures, and need not utilize staff members. To simulate a facility, one must enter staff information, resident information,

40
and building information. The building data is inputted as a network

derived from a floorplan of the facility, and consists of discrete nodes

and permissible connections between them. In the simulation, building

occupants travel in straight lines from node to node along the connections. Those residents who require aid are provided appropriate assis

tance by the staff member. The model computes and prints the time to

safety for each resident as well as his egress route, the total time to

clear the building, and a record of significant events that occur in the course of evacuation. One advantage of the model is its flexibility.

Residents of many different types may be simulated.. Also, once building

information has been inputted, factors such as initial location of

building occupants, resident types, order-of-rescue , egress routes, etc.

may be easily altered and the resultant variations in the evacuation

times observed.

The second simulation program, the Fire Emergency Evacuation Simulation for Multifamily Buildings, is also written in SIMSCRIPT II. 5.

It models the movement and actions that occur in emergency evacuations

of multifamily buildings, differing from the Escape and Rescue Model in

several ways. It assumes that all building occupants are fully capable

of unassisted egress once they are aware of the fire danger. Most occ- upants initiate egress almost immediately, but some residents only be

come aware of the fire threat when alerted by a staff member. The

alerting process is performed by a staff member, assigned to a particular floor (or floors), who systematically knocks on each. door of the

floor to ascertain if anyone still remains. (The simulation may be run without any staff) The building data is inputted as a network derived

from a floorplan of the structure. This process takes full advantage

of the fact that living units are clustered about long, straight hallways Given rather general information, the model can generate a node

for each living unit on the floor. Residents are randomly assigned to

each "generated" living unit based on criteria supplied by the user. Model output consists of a record of various events pertaining . to each

living unit and each stairway that occurred during the simulation.

At present, work is proceeding to convert the Escape and Rescue

Model into a user-friendly FORTRAN program. Many features have. been

added. The model user will be able to run the model either in interactive or batch mode on any machine with a FORTRAN 77 compiler. This

conversion process is almost finished. Next, the same conversion process will be performed on the Fire Emergency Evacuation Simulation for

Multifamily Buildings.

Reports:

1. Alvord, D. , The Escape and Rescue Model: A Simulation Mode l for

the Emergency Evacuation of Board and Care Homes , NBSIR-GCR-8 5-4 5

,

National Bureau of Standards, Washington, D.C. , December 1985.

41
2. Alvord, D. , The Fire Emergency Evacuation Simulation for Multifamily Buildings , National Bureau of Standards, Washington, D.C.,

forthcoming.

42
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution : Brown UniversityGrant No.: NB83NADA4025

Grant Title : Soot Dynamics in Flames

Principal Investigator : Prof. Richard A. Dobbins

Division of Engineering

Brown University

Providence, Rhode Island 02912

Telephone: (401) 863-1422

Other Professional Personnel : C. Megarides (Ph.D. student)

NBS Scientific Officer: Dr. George Mulholland

Technical Abstract :

This project focuses attention on the dynamic character of the

soot aerosol in a diffusion flame and seeks to provide details on the

role of the mechanisms of particle formation, coagulation, surface

growth, and particle oxidation as a function of height in a diffusion

flame. The research program consists of a theoretical study of the

aerosol general dynamic equation and an experimental study of the mor- phological character of soot determined by sampling soot particles

using methods which afford moderate spatial resolution. During the

first year the theoretical studies of the aerosol dynamic equation

with source and surface growth terms have been performed.

Methods of Solution of the Aerosol Dynamic Equation . Soot particles in flames are subject to particle formation, coagulation, surface growth, and oxidation, and their size distribution can in principle be described by the aerosol dynamic equation. The particles are

small compared with the mean free path of the gas molecules and are therefore in the free molecular regime. In this case there exists no exact solution to the aerosol dynamic equation and only approximate

solutions are available. An approximate numerical method has been

presented, for example, by Gelbard in the MAEROS code. Alternatively

integral solutions have been applied which are also approximate in that

they force the size distribution function to be of a prescribed form.

Earlier experimental studies indicate a log-normal distribution function to be approximately applicable and this form is well adapted to

the algebra of the integral solutions. The methods used to reduce

the data from optical experiments usually assume the distribution to

be static--a monodispersion or a self-preserving distribution.

However, neither of these two possibilities is justified if gas-to43
particle conversion is present either in the form of new particle formation or surface growth.

We have examined the relative merits of these two methods of solution. The numerical method is in principle a highly accurate technique

but is in fact subject to an approximation resulting from the sectioning of the size distribution function which limits the accuracy of the

method. The refinement of the section width requires a major modification of the code, which is not easily accomplished. The computer code

and computer running time is extensive by comparison with the integral

solution. The particle number concentrations yielded by the two

methods compare favorably when they are used to examine the initial

value problem. However even in this case the asymtotic long time

limit--the self-preserving particle size distribution function--is not

accurately predicted by the numerical method. The integral solution

comes somewhat closer to this limit if the figure of merit is the

dimensionless second moment given by

v

Here M2 is the second moment of the size distribution function, N is

the particle number concentration, and f

y

is the particle volume fraction. The value f^ = 1 corresponds to a monodispersion and f^ = 2.087

is the value given more recently by Graham and Robinson as applicable

in the self-preserving limit. The numerical method predicts a value

of f^ equal to about 2.60 while the integral solution gives 2.33.

Thus, it is apparent that the accuracy of the numerical method is quite

limited. (The quantity f^ is important in the interpretation of optical experiments. It is the multiplicative correction factor which

must be applied to the particle number concentration that is yielded

by Rayleigh theory for a monodisperse aerosol.)

An interesting development is revealed by the numerical (MAEROS)

solution when the source term is active. In this case the particles

being nucleated are assumed to be of a prescribed constant narrow size

distribution. The aggregate size distribution function of the total

aerosol population then is found to be bimodal in character. The

smaller mode (nucleation mode) corresponds to the distribution function of the newly formed particles. The larger mode (growth mode)

corresponds to the population formed by newly formed particles interacting with one another to produce a population of ever increasing

size.

The integral solution as presently implemented is monomodal in

character and does not allow for the development of a bimodal form.

Comparison of the numerical and integral solutions in these cases

shows serious discrepancies between the solutions. Thus, at the mo- ment of peak nucleation rates the second moment calculated by the

integral method is larger by 55% than the value predicted by the

44
integral solution. The number concentration is at later times influenced by this discrepancy and proves to be about 50% low. Likewise

the value of f is found by the integral method to be low compared to

the numerical method.

To correct this discrepancy we have formulated a bimodal integral

solution. This solution is of somewhat greater algebraic complexity

and its detailed implementation is temporarily being deferred pending

further information on the importance of this method of solution.

Comparison of Experimental Data with Predictions of Aerosol

Dynamic Equation . A more careful comparison of the predictions of the

aerosol dynamic equation with the data from the optical experiment is

being performed. In this case we use the integral solution with a surface growth term which is initiated at the moment when the nucleation term has a maximum. The form of the surface growth term is

assumed to be a half sine wave as a description of the rate of formation of the particulate phase by this mechanism. The final ratio of

surface growth to new particle formation is a controllable parameter

(Ag) . For Ag = 0 no surface growth occurs and for Ag = 1.0 the final mass of particles formed by the two mechanisms of gas-to-particle con- version are equal. For Ag >> 1.0 the maximum particle concentration

is small and little coagulative growth occurs.

When moderate to large initial particle sizes (10 to 50nm) are

assumed, we find poor agreement between the theory and the experiments

regardless of the value assumed for Ag. This indicates that the

initial size should be assumed to be very small. In this case both

the integral and numerical methods encounter a difficulty and cannot

run successfully. In the case of the integral solution the equation

for the time derivative of the particle number concentration has two

large terms on the right hand side when the source term is active.

The accuracy of the calculation of the derivative is low and numerical

instability ensues. This difficulty is currently being addressed by

redefining the independent variable to eliminate the two competing

terms of similar magnitude.

The physical implications of these mathematical results are important. In the region low in the flame where the intense particle

formation rate is present, there exists a quasi-equilibrium between

the source term and the coagulation term which directly controls particle number concentration. In this case the high particle concentration which is the driving force for coagulation results in the rapid

broadening of the particle size distribution and a rapid increase in

the quantity fj^. Thus the distortion of the particle concentration

profile is especially marked in this region of the high particle for

mation rate. Further, the smaller the initial particle size, the more

intense will be this distortion of the particle concentration profili

Optical experiments conducted on diffusion flames reveal a coin

cidence of the maximum particle size with the minimum particle conccn

45
tration in the region of intense particle formation rate. These

results are obtained when the size distribution function is assumed

to be of prescribed width throughout the space in which they are generated. The results we describe constitute evidence that the spatial variation of the particle size distribution function may be res- ponsible for this seemingly paradoxical observation. The improvement

of the computational techniques will permit the more detailed modeling

of the soot aerosol dynamics in the region of high particle production

rate. The results also are suggestive of particle morphological

features that should be investigated during the experimental work

which will ensue in the second year of this research.

46
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution : Brown University

Grant No . : NBS Grant NB83NADA 4017

Grant Title : Study of Effects of Material Properties on Flaming Combustion of Charring Fuels

Principal Investigator : Professor M. Sibulkin

Division of Engineering

Brown University

Providence, RI 02912

Telephone: (401) 863-2867

Other Professional Personnel : S. S. Tewari, Graduate Research Assistant

K. Siskind, Undergraduate Research

Assistant

NBS Scientific Officer: Dr. V. Babrauskas

Technical Abstract :

The objectives of the present research program are to determine

the effects of changes in material properties on the burning rates and

extinction limits of solid fuels, and to determine how fire retardants

affect these properties so as to cause extinction. Our emphasis has

shifted from "vaporizing" fuels (PMMA) to "charring" fuels (cellulose).

This year our efforts have been directed to the completion of a study

of burning cellulose samples, and to preparing for a study of the heat

of gasification of pure and fire retarded cellulose.

The flaming combustion of charring materials was studied using samples prepared from pure cellulose and from cellulose which had been fire

retarded by the addition of sodium hydroxide and sodium carbonate. Vertically oriented, hemispherical nosed cylinders were burned at atmospheric pressure in mixtures of oxygen and nitrogen. In general, the

burning rates showed slight to moderate decreases with time while the

surface temperatures increased with time. Both trends are related to

the increase in char layer thickness with time. Extinction was observed to begin at the stagnation point and then move downstream until

the flame was completely extinguished. Examples of the burning rates

for pure cellulose are shown in Fig. 1. Addition of a fire retardant

to the cellulose fuel gave unexpected results (see Fig. 2). While a trace amount of retardant, 0.1 percent, causes a 10 percent reduction

in burning rate, addition of more retardant has a negligible effect on burning rate. However, the amount of retardant needed to cause ex- tinction varies with the oxygen concentration. Our extinction results

are summarized in Fig. 3. For pure cellulose both stagnation point and

complete extinction occur for Yq ^

- 0.18. As the oxygen concentration

47
is increased above this value, the amount of retardant needed to cause extinction increases rapidly while the difference in Yr between stagnation point and complete extinction also increases. At sufficiently high

oxygen concentrations no extinction is found for the retardant concentrations used in this study. A practical consequence of these findings

is the need to exercise proper caution in using "fire retarded" cellulose products in oxygen enriched atmospheres. A paper presenting the

results of this investigation is now in press.

The next major phase of this project is the measurement of the effective heat of gasification of the materials used in the flaming com- bustion study. This property is central to diffusion flame theory. An

analysis was made to determine the relationship of the heat of gasification hg, defined as hg = q" (in) /m" (out) , to the heat of pyrolysis,

defined as hp = h.(Tw) [gas + char] - h(Too) [cellulose]. It is shown

that hg = hp only in the case of a pyrolysis wave moving through the

material at a constant velocity. This is not the case for charring

materials. Numerical calculations will be made to model the pyrolysis

of cellulose and determine the effects of changes in material properties on the rate of volatile production and the heat of gasification.

A major effort is underway to complete the installation and calibration of the apparatus for the measurement of hg. A plan view of the

installation is shown in Fig. 4, and a side view of a portion of the

apparatus is shown in Fig. 5. The heart of the apparatus is an electronic balance with a specially designed sample holder mounted within an extensively modified glass draft-shield chamber. A 2-stage gas supply

system has been developed to first scavenge air from the chamber and re- place it by an inert gas, and then to supply a reduced flow of inert gas

to remove the products of pyrolysis. The exhaust gas from the chamber

can be passed through a gas chromatograph to either detect traces of

oxygen before pyrolysis or to analyse the volatiles during pyrolysis.

The sample is heated by a radiant lamp assembly which has been designed

to give a uniform surface heat flux with an intensity which simulates

the energy flux to the sample surface during burning. The surface temperature during pyrolysis is measured using an infrared pyrometer with a 2.1 ym detector which can "see" through the chamber window. The pyrometer is installed with a rotating mount to facilitate its calibration

against a black-body furnace. The incident heat flux at the sample location is measured with a Gardon type radiation gage which has been

calibrated at NBS. A number of water-cooled heat shields have been included in the design to minimize the heating of the electronic balance.

Reports and Papers :

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

"Comparison of Theoretical and Experimental Burning Rates for Wall Fires,"

S. F. Malary and M. Sibulkin, J. Fire Sciences, under review.

48
"Effects of External Radiation on Solid-Fuel Diffusion Flames," M. Sibulkin and T. Gale, J. Fire Sciences, in press.

"Measurements of Flaming Combustion of Pure and Fire Retarded Cellulose,"

M. Sibulkin and S. S. Tewari, Combustion and Flame, in press.

"An Experimental Study of the Burning of Pure and Fire Retarded Cellulose, S. S. Tewari, Ph.D. Thesis, Brown University (1984).

Fig . 1

m

(g/s)

Fig. 2

49
50
ANNUAL CONFERENCE ON FIRE RESEARCH

CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

GAITHERSBURG, MARYLAND

October 17-19, 1984

Inst itut ion : 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, Engr. Degree

Michael Chobotov, Ph.D. Candidate

Jean-Pierre Huot, Ph.D. Candidate

Steve Toner, Pk.D. Candidate

California Institute of Technology

Pasadena, CA 91125

NBS Scientific Officer : Dr. Walter Jones

Dr. J. G. Quintiere

Technic al Abstract :

Smoke which is produced by a fire spreading through a building can

act to aid in the spread of the flame by the transport of hot and

perhaps combustible gas, and can be harmful to occupants because of its

temperature and toxicity or because its opacity hinders the rapid

movement of the occupants through the building. We are interested in

developing models for the production and movement of smoke in complex

structures and have been studying several processes which will be

described below. These processes can not be described analytically

because the flows are turbulent and are strongly influenced by

turbulent mixing between streams in which buoyancy forces are predominant. Under certain circumstances, the combustion of the fuel

produced in the fire can occur under conditions in which the

concentration of oxygen in the ambient gas is far below normal and a fuel rich mixture can be produced in the smoke which can burn later in an adjacent space. The aim of the research work described here is to

develope sufficient understanding of the fluid dynamic and chemical

processes that rational models can be developed for the use in two

layer fire codes.

51
Experimental Progress:

Mixing in a Doorway. During the past year we have completed work

concerned with mixing, between the two layers within a room, which is

caused by currents flowing into and out of a doorway. The currents in our experiments modeled those that would be produced by a fire burning

with a steady heat release rate located within the room.

The mixing process was complex and involved in some detail the flow

within the room which was produced by the inflowing fresh air and also

the outflowing jet of hot gas. The inflowing stream produces a jet

which interacts both with the upper or hot gas layer and with the gas

within the cool or floor layer which may be at a higher temperature

than the ambient fluid due to entrainment from the upper layer.

Entrainment of hot products of combustion from the upper layer into the

lower layer occurred primarily at the interface between the inflowing

jet and the ceiling layer gas but some mixing occurs all across the

interface between the two layers.

A correlation was developed which predicts the entrainment for the

geometric configurations we examined experimentally as a function of a Richardson number parameter. This correlation and the supporting data are discussed in a thesis by Lim, Ref 1. The results certainly depend

on the geometry of the room used in the experiments but we believe that

the correlation will give a useful estimate for this mixing process as long as the geometry of the room and the doorway are not drastically

different from that investigated experimentally.

Combustion in the Ceiling Laver. We are continuing an investigation of

the heat release in the ceiling layer when a flame extends far into

that layer. The problem here is to predict the composition and heat

release from the fire when a substantial part of the flame and

combustion processes occur above the interface between the cool

unvitiated gas in the lower layer and the hotter, vitiated gas in the

ceiling layer. Combustion can continue even when the oxygen

concentration in the upper layer is zero because oxygen is entrained

into the flame from the the lower layer.

The results obtained during the past year are presented in the thesis

by Lim, Ref 1. For conditions in which the fuel-air ratio of the gases

entering the ceiling layer were less than stoichiometric, the

experiments are satisfactory and show that the combustion within the

flame is almost complete. However, when the fuel-air mixture in the

fire plume is very fuel rich, our measurements are not as accurate as we want because our instrumentation technique did not permit

concentration measurements for hydrogen bearing species. New

experiments are being carried out in the current year to correct this

s ituat ion .

Gravity Currents. We are interested in modeling the initial motion of

smoke and hot gas in a long hallway or large room when hot gas is

introduced into the space for the first time either through an opening

52
or from a fire located within the space.

To have a concrete example in mind, consider the development of the

ceiling layers produced by a fire in the two-dimensional structure

shown in the sketches of Figure 1. Smoke spreading from a fire in a small room spills out under a door soffit into an adjoining hallway.

The outflowing gas forms a buoyant plume, see Figure la, which impinges

on the ceiling of the hall and produces a thin, high speed wall jet or gravity current. The flow in this wall-jet is supercritical, and the

interaction of the head of this current with the ambient fluid produces

a hydraulic jump in the supercritical layer, which entrains a substantial flow of ambient fluid. The gravity current formed

downstream of this jump propagates across the ceiling with a constant

depth and velocity, and little mixing.

A short time later, see Figure lb, the front of this current impinges

on the far wall of the hall and reflects as a group of waves on the

interface which propagate back toward the jump. Mixing occurs during

the impingement process but the waves do not break and do not cause any

further entrainment or mixing. When the waves reach the hydraulic

jump, the jump is submerged and no further entrainment of ambient fluid

occurs there.

Heat transfer from the hot gas to the wall occurs throughout this

process and it will affect the motion of the current, since the

buoyancy of the current will be reduced.

Entrainment in the hydraulic jump is clearly an important feature of

the flow described above. The total mass entrained into the layer

depends on the entrainment rate and on the period during which it will

act. This period is fixed by the geometry of the room, and the

velocity of the front of the current and of the reflected waves which

eventually submerge the jump. These features must be included in any

accurate model of the flow. Also, there are situations in which the

motion of the current can be important. For example, if the gravity

current is deep enough to submerge a sprinkler system, the motion of

the front will determine when the sprinkler can be set off.

The aim of the present experimental program is to obtain a good

physical understanding of the important features of these flows and to

develop analytic models for application in multi-room fire codes. This

work will include a study of the processes which occur in the hydraulic

jump at the entrance to the hallway and other entrance conditions not

discussed here.

Two facilities have been constructed. The first is a square duct 0.6 m

on a side and about 8 m long which will be used to study the motion of

gravity currents of hot gas. The quantities being measured include

velocity and temperature fields, and heat transfer to the walls. Tbe

emphasis will be placed on the investigation of the effects of heat

transfer on the gravity current.

53
Many problems in describing horizontal flows of smoke in buildings

arise because of geometric complexities of the space involved and these

can be most conveniently studied with a water modeling technique in the

second facility. The experimental technique used here involvings saltwater/water modeling: the geometry is inverted, salt water is used to

model the hot gas, and water is used to model the cooler ambient fluid.

The second facility is a model hallway 15 cm on a side and 250 cm long.

To facilitate the study of flows at high Reynolds numbers, we also have

access to a duct 1 m on a side and 20 m long. The effects of viscosity

and density difference on flow will be investigated in these facilities

in flow visualization will be a primary tool, addition, many problems

in describing horizontal flows of smoke in buildings arise because of

geometric complexities of the space involved and these can be most

conveniently studied with this water modeling technique.

Figure 1. Gravity Current Flow in a Hallway

Reports and Papers :

1. C.S. Lim, "I. Mixing in Doorway Flows; II. Entrainment in Fire

Plumes," Aeronautical Engineer Thesis, California Institute of

Technology, Pasadena, California (1984).

2. B.M. Cetegen, E.E. Zukoski and T. Kubota, "Entrainment in the Near

and Far Field of Fire Plumes," Combustion Science and Technology,

(To Be Published).

3. E.E. Zukoski, B.M. Cetegen and T. Kubota, "Visible Structure of

Buoyant Diffusion Flames," 20th Symposium (International) on Combustion, The Combustion Institute, Pittsburgh, Pennsylvania

(1984).

54
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Is.ALi13111° n : Case Western Reserve University

ISSlSSSl Number : NB82NADA3028

Cont.ra_£t. Tit.1^: Experimental and Analytical Study of Fire

Sprinkler Scaling Laws

IsiSSAESl Inv es tiga to r; Joseph M. Prahl, Ph.D., P.E.

Assoc. Professor of Engineering

Department of Mechanical and

Aerospace Engineering

Case Western Reserve University

Cleveland, Ohio 44106

NB S S ci entific Offi ce r: David D. Evans

Tec hn ical 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 dimensionlessly to the

mechanical and thermal properties of the liquid and gaseous

fluids, the geometry and the initial dynamics of the liquid

and gaseous streams.

Experimental data for water has been obtained on an

apparatus developed to study the axisymmetric jet impingement on a flat disk which can be vibrated axially at a given

frequency and chosen amplitude. The sheet of water leaving

the disk is allowed to breakup without interference over the

full 360°, whereas the discharge subsequent to sheet breakup

is masked off to a 22.5° sector for the purpose of

determining the droplet radial discharge distribution. The

sheet breakup radius is determined by direct observation and

the radial discharge from the sector is collected in a series of rain gutters spanning the floor of the sector

normal to the midangle radial direction. Variation of disk

size and disk surface characteristics show no measurable

effect on either sheet breakup radial location or on

the measured discharge distribution.

Comparisons of the measured breakup radii with those of

Huang [1] show qualitative agreement. Huang's experiment

studies the sheet resulting from the impingement of two op55
posing jets, whereas the present work considers the sheet

produced by one jet impinging normal to a disk. To obtain

quantitative agreement, the present work requires a disturbance amplitude ratio of exp(18) compared with Huang’s

exp(33), and Weber's original value of exp(12). The breakup

radius normalized by the nozzle diameter and the Weber

number to the minus one third power, plotted versus the

frequency of disk oscillation normalized with respect to the

frequency of maximum growth rate, the jet velocity divided

by the nozzle diameter all times the Weber number to the

plus one third power, see Figure 1, shows the minimum

breakup radius occurs at a frequency of about 1 to 2 maximum

growth rate frequencies.

The sprinkler flow distribution is presented in a nondimensional form which emphasizes the sprinkler's ability to

uniformly spread the volume flow rate of water over the

maximum possible floor area. The maximum radia l extent of

the sprinkler system is represented as U / 2y / g , where U is

the jet velocity, y, the distance of the disk above the

floor and g, gravity. The non-dimensional application rate

is the measured 'rain rate’ from the gutter collection system, normalized with respect to the 'ideal rain rate', the

total flow rate from the nozzle divided by the maximum

possible floor area. Figure 2 shows a typical distribution

compared with the uniform distribution that would result

over the maximum floor area.

An analytical relation for droplet trajectories is

being developed for comparison with the measured discharge

distribution so that droplet size distribution can be inferred. Work is progressing on isolating the effect of

oscillation amplitude on the sheet breakup radius. The

discharge distribution from some commercially available

sprinkler heads will be determined and compared using the

non-dimensional scheme presented above to establish the validity and usefulness of this approach to sprinkler system

performance comparisons.

Eitorts and P ub 1 i ct ion s

1. B. Wendt and J. M. Prahl, 'Flow Rate Distribution Performance for an Axisymmetric Vibrating Impact Fire

Sprinkler Head', Department of Mechanical and Aerospace

Engineering, Case Western Reserve University, Cleveland,

Ohio 44106, Dec. 1983.

R efe rences

1. Huang, J., 'The Breakup of Axisymmetric Liquid Sheets',

JFM, Vo 1 . 43, part 2, pp . 305-319, 1970 .

56
Figure 1. Nondimens ional breakup radius versus nondimensional

frequency for flow rates from 14.6 to 19.1 liters/minute

<

O

Figure 2. Nondimensional application rate versus nondimensional radius

at zero frequency for flow rates of 17 and 19 liters/minut:-'

57
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

I ns titu tion : Case Western Reserve University

Grant No.: 60NANB4D0013

Gran t Titl e: Flame Spread and Spread Limits

P jr i^n£_ipa.X Inves ti gator : Professor James S. T'ien

Dept, of Mechanical and Aerospace

Eng ineer ing

Case Western Reserve University

Cleveland, Ohio 44106

Other P r oXe. s. s. i.o n

1, Personnel : Charlie Chen (Graduate Student)

Ait Messaoudene (Grad. Student)

NBS Sc ient i f ic Offi c er : Dr. James G. Quint i ere

Te.£hn i.£a.l. Abstra ct

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

Qua si- gl oba l K inetic s of PMMA. Recent modeling work on

solid fuel burning has utilized quasi-global chemical

kinetic schemes. In the first step fuel and oxygen are to

form CO and H

2 O, subsequent steps convert CO to CO 2 and CO 2

back to CO. In trying to compare model prediction with

experiment, it was found that no kinetic data exists for the

most common solid fuels for their first quasi-global

oxidation step. A method for deducing those data is to

compare the stagnation point flow calculation with

extinction experiments. Since the extinction boundary

already exists for PMMA, a numerical model with the abovementioned kinetics is being set up. We expect that the

oxidation data for PMMA applicable to quasi-global kinetics

should appear shortly.

Dj.ffu.si.on Flame . For combustion of a solid fuel plate in a convective flow, a major portion of

the combustion zone can be treated by the boundary layer

58
approximation. However, this is not applicable to the

leading edge of the flame (upstream) because streamwise heat

conduction is essential there for flame stabilization. For

a number of applications, a detailed analysis in this region

becomes necessary. A more sophisticated model has been

formulated and is being solved numerically to address the

question of flame extinction and blowoff. This also will

provide the upstream condition for boundary layer analysis

when finite-rate kinetics are important.

Report s an d P ap ers

Chen, C.H. and T'ien, J.S., 'Fire Plume along Vertical

Surfaces: Effect of Finite-Rate Chemical Reactions', Fire

Dynamics and Heat Transfer, HTD - Vol. 25, p. 17-28, Edited

by J. G. Quintiere et al., ASME (1983). Also to appear in

Journal of Heat Transfer.

59
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 8

Institution: Clemson University

Grant No . : NBS Grant NB80NADA1042

Grant Title : Ternary Reactions Among Polymer Substrate-OrganohalogenAntimony Oxides in the Condensed Phase Under Pyrolytic,

Oxidative and Flaming Conditions

Principal Investigator : Dr. M. J. Drews

School of Text i 1 es Clemson University

Clemson, South Carolina 29631

Other Professional Personnel : Dr. C. W. Jarvis, Co-principal Investigator

Dr. J. Reece, Post-doctoral Research

Associate

Mr. T. Gilstrap, 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/organohalogen/

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 organoha 1 ogen/ant imony oxide flame retardant combinations in specific

polymer substrates.

Three polymers and three organobromi ne compounds of significantly

different thermal stability and primary decomposition pathways were

chosen in an attempt to generalize the results of this study to other

systems containing oxides of antimony. The polymer substrates are polyethylene terephthal ate (PET), polypropylene (PP) , and polymethylmethacrylate (PMMA) . Decabromod i phenyl oxide (DBDPO) , tetrabromobi s- phenol-A (TBBPA) and hexabromocyclododecane (HBCD) are the organohalogen

compounds being used as the model halogen sources.

60
The research plan is divided into two concurrent pathways: a set

of small scale degradation studies and a series of laboratory scale

flaming combustion experiments utilizing the cone calorimeter at the

Center for Fire Research at the National Bureau of Standards.

The small scale work employs isothermal and dynamic thermal

analysis, and isothermal tube furnace experiments with antimony and

bromide ion monitoring of the volatile products as a probe into the

solid phase reactions. From these data a temperature profile of antimony

and bromide ion (or HBr) volatilization is also developed. The basic

experimental sequence consists of a study of the individual components

followed by the binary mixtures (pol ymer/organohal ogen , polymer/antimony

oxide and organoha 1 ogen/ant imony oxide) followed by the ternary mixture.

In the combustion experiments, only the three polymer substrates

and the ternary mixtures at different ratios of polymer to organohal ogen/

antimony oxide additive are studied. In these experiments 0 2 depletion,

CO and C0 2 formation, mass loss and sample temperature as a function

of time as well as relative gravimetric smoke yield are measured.

The small scale degradation studies on the individual components

and the binary mixtures have been completed. The most important

conclusion is that no reactions have been observed in these mixtures

which could account for the antimony volatilization which occurred in

the flaming combustion experiments of those samples containing either

DBDP0/Sb 2 03 or TBBPA/Sb 2 03. For these two organohal ogen compounds,

which do not readily dehyd roha 1 ogenate , a polymer substrate must be

present for significant antimony volatilization to occur.

The complete interpretation of the small scale degradation work has

been hindered by difficulties encountered in obtaining mass balances for

antimony and bromine. To overcome these problems, sequential thermal

analysis and tube furnace pyrolysis experiments have been employed to

study the system PP/DBDP0/Sb 2 03 . The results from these new experiments

have clearly demonstrated the critical nature of the solid state

chemistry in controlling the generation of volatile antimony species

from this system. These data suggest that the formation of volatile

antimony from this ternary mixture may involve pathways which have not

been previously reported. New experiments using electron spectroscopy

for chemical analysis (ESCA) and new analytical procedures are currently

in progress.

While the combustion data analyzed to date represent a limited

sample, 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 buring candlelike geometry using thermally thick samples is

surprising but in accord with the basic hypothesis of this work.

61
This initial data set consisted of 28 experiments conducted over a period of two years which generated approximately 100,000 observations.

Analysis of these data points has Identified several Internal

inconsistencies, which apparently resulted from modifications to

various procedural aspects of the burns. Consequently, a totally new

set of data acquisition software has been written to eliminate these

problems in future experiments.

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

organoha 1 ogen/ant imony 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., "Organobromi ne/Ant imony

Oxide/Polymer Substrate Interactions in the Solid Phase. Part I. Binary Interactions," Organic Coatings and Plastics Preprints, 43, 1 8

( 1980 ).

Gilstrap., T. L., "A Study of Polymer/Ant imony Oxide Interactions During

Pyrolysis," Masters Thesis, Clemson University, May 1984.

Hansel, J. D., "Solid Phase Interactions Among Antimony Oxides,

Decabromod i phenyl Oxide and Polypropylene Under Pyrolytic Conditions,"

Masters Thesis in preparation.

62
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

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 Paaba

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.

During the first two years of the program, the methodology was developed and applied primarily to nonflaming aerosol analysis. The

summary of this work is reported in the first paper listed under

Papers and Reports . In addition, work was done using a modified

approach of the methodology for analysis of gasoline in aerosols from

possible arson investigation. The work is summarized in the second

paper listed.

63
The major effort for the past year has been the analysis of

aerosols from large scale flaming combustion. The cone furnace at NBS

was selected based on past work which indicated that the aerosols

formed from this furnace were more similar to full scale aerosols than

the aerosol generated in the Potts furnace in the flaming mode. Two

pound samples were used in all decompositions. Twenty-one materials

were used in the study to form mixtures containing up to four

components. All mixtures were formulated by NBS staff and were used

in the study in a blind mode.

Table 1 summarizes the results of the visual characteristic peak

analysis of the aerosol pyrolysis data. About 58 percent of the

compounds were identified in the study. More importantly the table

presents trends where it is clear that the identifications are based

on the class of the polymer. For example, the polyurethanes are identified 100 percent correctly while materials such as polyethylene

were not identified in any of the analyses. Examination of the mass spectra associated with the various polymers indicates that for those

materials which are identified with a high degree of confidence,

strong characteristic peaks are present. For materials like

polyethylene, a large number of equal intensity peaks are present.

Factor analysis has been conducted on some individual mixtures

containing both materials which were easily identified as well as never identified. The results of the analysis on a limited number of

samples are nearly 100 percent identification. Unfortunately, factor

analysis has not been completed on the entire data set.

These results show that fuels involved in flaming combustion can

be identified with varying degrees of confidence. Future work will be

focused on evaluating identification conficence levels for an expanded

group of materials.

Papers and Reports

Rushung Tsao and Kent J. Voorhees, "Analysis of Smoke Aerosols from

Nonflaming Combustion by Pyrolysis/Mass Spectrometry with Pattern

Recognition," Analytical Chemistry, 1984 , 56, 368-373.

Rushung Tsao and Kent J. Voorhees, "Fingerprinting of Gasoline in

Combustion Aerosols by Pyrolysis/Mass Spectrometry with Factor

Analysis," Analytical Chemistry, 1984

,

56, 1297-1301 .

64
Table 1

The result of flaming combustion in MBS cone combustion

chamber

Mixture

Standard Materials

A* B C D EF GHI JK L MNOP Q

1 +

2 + +

3 + + +

4

5 + +

6 + — +

7 + + +

8 + -

9 i i + +

10 + - + + +

11 i + + i + i

12 + i i + i + i

13 + - + +

14 +

15 + + - +

16 + + +

17 - +

18 +

19 + +

20 + - +

21 + +

22 + +

Success

rate (%) 73 0 17 100 100 0 100 80 0 100 83 100 100 0 67 25 100

*Materials: A. Douglas fir, B. cardboard, C. cotton.

D. polystyrene, E. polyurethane GM-29, F. polyethylene

sheet G. PVC pipe, H. nylon carpet, I. polyester

carpet, J. polyurethane GM-21, K. ABS pipe, L. Coke

bottle, M. polyurethane GM-24 , N. acrylic blanket,

0. wool blanket, P. PVC sheet, Q. plexiglas

65
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution: Factory Mutual Research Corp., Norwood, MA 02062

Grant No : NB83-NADA-4014

Title : Calculated Interaction of Water Droplet Sprays

with Fire Plumes in Compartments

Principal Investigators : Dr. Ronald L. Alpert

Basic Research Department

(617) 762-4300, ext. 2776

Other Professional Personnel: Dr. Mary Delichatsios

Ms. Mary K. Mathews

Dr. John de Ris

NBS Scientific Officer: Dr. Bernard McCaffrey

Technical Abstract : The objective of this program is to predict mathematically the

interaction of water droplet sprays with fire plumes in compartments. Our goal is to obtain general interaction correlations relating spray penetration and cooling of the fire environment to

controlling spray and fire plume parameters. Another primary objective of the program is to provide a rugged computer code that can be

transferred to CFR/NBS for routine, cost-efficient calculation of

spray cooling and penetration.

In our research approach, two major tasks are being

undertaken. In the first task, a simplified, axisymmetric problem

is being studied by a numerical modeling technique (TEACH-T) now in

use at FMRC. Calculations are performed giving spray penetration,

spray cooling and gas flows for a fire simulated by a zone of uniform volumetric heat release. Because these calculations use excessive computer time, we have undertaken a major effort (Task 2) to

improve the accuracy, numerical stability and computational efficiency of the existing code. The improved computer code will then

be tested against existing analytical solutions, and used to perform

applied calculations for a broad range of sprinkler, fire and com- partment configurations.

Current Calculation Technique : The axisymmetric flow induced by the

impingement of a buoyant plume on a ceiling has been studied previously in some detail at Factory Mutual, NBS and elsewhere because

such a flow is associated with hazardous fires in buildings. Plume

impingement results in the development of a ceiling-jet of hot gas

flowing radially outward from the plume axis. An array of automatic, fire suppression sprinklers actuated by the ceiling-jet initiate droplet sprays which must cool the hot gas flow while providing a flux of liquid to the burning fuel.

Although the complete, three dimensional problem of predicting

actuation patterns for a sprinkler array is far too complex at present, a simpler, axisymmetric problem is being considered to investigate the plume-spray interaction. In this axisymmetric problem, a

66
downward facing spray is assumed to be located on the axis of a rising buoyant plume from a fire. To simulate the spray from a fire

suppression sprinkler, droplet trajectories originate from a point source at the ceiling with uniformly distributed initial trajectory

angles up to a maximum of 90° from the vertical. The liquid mass flow rate injected along each trajectory is adjusted to give a uniform mass flow per steradian in the spray envelope. The fire plume source is simulated by specifying uniformly distributed sources of

volumetric energy addition within a cylindrical (flame) region at a rate of 1200 kW/m^ (based on measurements in propane pool fires by

Orloff and by Santo and Delichatsios at Factory Mutual).

The numerical computation code used for this problem is a modified version of the widely used TEACH-T elliptic code for recirculating gas flows. Results of the numerical calculations consist of a description of the properties of the induced air flow field along

with detailed droplet trajectories.

Plume-Spray Calculation Results : Calculations are performed first

with a plume source alone, without a spray, in order to verify the

accuracy of the numerical technique for a buoyancy dominated flow.

Patterns of air streamlines and plume gas temperatures and velocities have been compared with experimental measurements. The results

obtained with a crude 16 x 16 point mesh agree within +_ ( 15 to 30%)

with existing plume correlations.

With the simulated sprinkler at the ceiling boundary and the

plume source at the floor boundary, a numerical solution is next

obtained for the resultant flow field. Figure 1 shows the calculated air flow streamlines when a droplet spray of 4.6 kg/s total

water flow operates in the presence of the distributed heat source

plume. The main effect of this spray is to deflect the incoming air

flow (to be entrained by the plume) downward and to sharply decrease

the peak excess gas temperature at the ceiling. A much greater

effect on the plume flow field is achieved if a narrower outer spray

angle (57.3° from the vertical instead of 90°) is used, even with a reduced water flow rate.

Another feature of interest in these calculations is the behavior of droplets in the different trajectories of the spray. Asterisk symbols in the figure indicate the innermost and outermost trajectories. Under certain conditions (reduced water flow rate and/or

small droplets) the downward motion of the inner droplets may be

completely stopped and reversed by the upward thrust of the plume,

and this may have important implications for fire suppression.

Of particular interest is the efficiency of spray cooling and

penetration of droplets through the plume. Correlations are being

developed from the calculated flow properties to show how the total

energy absorption by the spray and the near-ceiling flow conditions

depend on the relative strengths of the spray and plume. The spray

water flow reaching the plume source at floor level compared to that

in the absence of a plume is also being correlated as a function of

plume and spray properties. This penetration ratio ultimately

determines whether direct extinguishment of a fire is possible.

67
Improvements to the Calculation Algorithm : The numerical technique

used for the preceding spray interaction problem allows a description of spray-induced flow fields to be obtained, but at a considerable cost in computer time (roughly 10 minutes on the IBM 370/158

even for relatively course 16 x 16 mesh spacings). Much more efficient gas phase algorithms are clearly needed to make accurate

numerical solutions of buoyant turbulent flows in large-scale

domains practical.

During our first year program, we have examined potential

improvements in the accuracy of the code. Strict second order

spatial accuracy and, possibly, second order temporal accuracy are necessary for our practical applications. We have analyzed a quadratic upwind ADI (alternating direction implicit) algorithm that

appears to satisfy most of the requirements for accuracy and stability.

Considerable emphasis has also been placed on improving the

iterative solution of the coupled pressure-velocity equations which

presently consumes most of the computation time in the numerical

code. The new methods analyzed make use of highly efficient algorithms for solving the pressure equation directly and thus reduce

the number of required iterations.

Recent Developments : New boundary conditions have been incorporated

into the TEACH-T code to better simulate compartment fires. Calculations are in progress for the case of a ceiling (or floor) boundary obstructed by an axisymmetric partial side-wall (or curtain

wall). This boundary condition results in the formation of a hot

gas layer within which the usual ceiling-jet and the spray origin

are submerged. Converged solutions are being obtained with this

partial side-wall boundary condition for the case of a plume without

a spray. Calculations are also being performed to determine the

spatial variation of response times of typical thermally actuated

detectors. In order to properly visualize the buoyancy-induced

streamlines and the detector response time variations near the sidewall boundary, more accurate contour fitting routines are being

developed.

Another code enhancement already completed allows for the simulation of a hot-jet plume source in an annular region at the floor

boundary. Calculations to be performed with this boundary condition

can be compared directly with measurements of spray penetration and

cooling in an annular hot -jet planned for later this year by

NBS/CFR.

Conclusions and Future Plans : Sample problems involving interactions of droplet sprays with buoyant flows have been solved numerically. Calculated properties of the interaction flow field in many

cases appear to depend on a ratio of droplet spray momentum to that

induced by the buoyancy source. It is expected that improved correlations of this type, developed from more extensive calculations,

should prove to be useful for the optimization of water spray protection.

68
Because these calculations use excessive computer time, we have

undertaken a major effort to improve the accuracy and computational

efficiency of the present code. During the second year program we will refine the improvements to the computer code and will perform

applied calculation for a broad range of sprinkler, fire and compartment configurations.

Reports and Papers

1. Alpert , R.L. , "Calculated Interaction of Sprays with Large-Scale

Buoyant Flows," Journal of Heat Transfer, Vol. 106, May 1984,

pp. 310-317.

2. Alpert, R.L. , "Numerical Modeling of the Interaction Between

Automatic Sprinkler Sprays and Fire Plumes," paper presented at

a Symposium on Computer Applications in Fire Protection, Society

of Fire Protection Engineers, Leesburg, Virginia, March 19-20,

1984.

3. Beier, R.A. , de Ris, J. , Baum, H.R., "Accuracy of Finite

Difference Methods in Recirculating Flows," Numerical Heat

Transfer

,

Vol. 6, No. 3, pp. 283-302, July-Sept. 1983.

GAS STREAMLINES* SPRAY-PLUME INTERACTION

69
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution ; Factory Mutual Research Corporation

Norwood, Massachusetts 02062

Grant No.

NB83NADA4021

Grant Title; Determination of Fuel Parameters for Fire Modeling

Principal Investigator ; Archibald Tewarson, Ph. D.

Senior Research Specialist

Manager, Flammability Section

Factory Mutual Research Corporation

1151 Boston-Providence Turnpike

Norwood, Massachusetts 02062

Other Professional Personnel ; J. A. Steciak

S. D. Ogden

NBS Scientific Officer; Dr. V. Babrauskas

Technical Abstract ;

The objective of this grant study is to examine the scale effects

on the fire properties of materials (combustion and generation efficiencies of chemical compounds and "smoke" properties)

The experiments were performed in the Factory Mutual (FM) SmallScale Apparatus (M3.1 m sample), FM Intermediate-Scale Apparatus

(y0.3 m sample), and FM Fire Products Collector (materials arranged

within the dimensions of ^3 x 3 x 3 m) . In addition, experimental re- sults reported in the literature for wood crib enclosure fires were

used for the scaling study.

The materials and arrangements used in the study were:

1) three-dimensional arrangement of materials: cellulosic (corrugated

paper cartons, shredded paper and wood cribs) ; cellulosic-aromatic

(corrugated paper and polystyrene) and three semi-rigid foams;

2) horizontal pool-like arrangement: polymethylmethacrylate, polystyrene, and polyvinyl chloride; and 3) sheets of five aircraft paneling materials.

For scaling, the heat release rate and generation rates of chemical compounds were normalized by the generation rate of fuel vapors.

Overventilated fire conditions were used in the experiments.

From the experimental data obtained in this study as well as in

70
our previous grant study for pool fires, it was found that combustion

chemistry is conserved for overventilated turbulent fires. This finding is based on the fact that combustion and generation efficiencies

of CO, CO , ^0, and hydrocarbons show little dependency on fire size,

configuration and arrangement of materials. This finding is consistent

with the Schvab-Zeldovich scalar correlations of de Ris and Orloff.

From the experimental results for wood cribs measured in our apparatus and data reported in the literature for wood crib enclosure

fires, it was found that mass air-to-fuel stoichiometric fraction was

a useful parameter for the correlation of the data.

The data from this grant study are used as inputs to fire models

for designing a known degree of fire protection into an occupancy and

for improving materials for passive fire protection.

Reports and Papers :

1. Tewarson, A. and Steciak, A., "Fire Ventilation," Combustion and

Flame , 53, 123, 1983.

2. Tewarson, A., "Fully Developed Enclosure Fires of Wood Cribs,"

Paper accepted for 20th Symposium ( International) on Combustion , The Combustion Institute, Pittsburgh, Pennsylvania, 1984.

3. Tewarson, A., "Scale Effects on Fire Properties of Materials,"

Technical Report, National Bureau of Standards grant study

(to be issued August 1984).

71
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution : Factory Mutual Research Corporation

Grant No . : NB83NADA4054

Grant Title : Effects of Water Discharge Rate and Drop Size on Spray Cooling in Residential Fires

Principal Investigator ; Hsiang-Cheng Kung

Manager, Applied Mechanics Section

Factory Mutual Research Corporation

1151 Boston-Providence Turnpike

Norwood, Massachusetts 02062

Other Professional Personnel : Dr. Hong-Zeng You

William R. Brown

NBS Scientific Officer : Edward K. Budnick

Technical Abstract ;

A research program is being conducted to investigate spray cooling in room fires. The objective of this program is to investigate:

1) the spray cooling ability in a room as affected by water discharge

rate, drop size distribution, and fire size; and 2) thermal response

of remote sprinkler links before and after sprinkler operation.

The program is of experimental nature. Most of the fire tests

will be conducted in a 3.66 m x 7.32 m x 2.44 m high test room. To

explore the effect of room size, a limited number of fire tests will

be conducted in a larger room (4.27 m x 8.54 m x 2.44 m high). The

fire source used in the program is an easily reproducible heptane

spray fire. Three constant heptane consumption rates have been se- lected to approximate heat release rates of upholstered furniture at

sprinkler actuation.

Sprinkler sprays generated from three geometrically similar

sprinkler nozzles are being investigated. The linear-scale ratios of

the nozzles, referenced to the largest nozzle, are 1, 3/4 and 5/8.

For each nozzle, three water discharge pressures will be tested.

Only one sprinkler nozzle is installed at the ceiling inside the

test room. The water flow to the nozzle is controlled by a solenoid

valve immediately upstream of the nozzle. A simulated residential

sprinkler link (RTI value: 28 (sec x m) 1 ' ) is used to actuate the

solenoid valve through a temperature controller when the link

72
temperature reaches a predetermined value.

Construction of a calorimeter (fire products collector) has beercompleted. The calorimeter consists of a 2.44 m diameter hood, a 0.61 m diameter stack and other duct work. An electric blower has been

installed at the duct outlet. The calorimeter will be used to collect

the combustion gases exiting from the opening of the test room and to

measure heat release rates of the effluent gases. A 0.36 m diameter

orifice plate has been installed at the stack inlet to achieve uniform

flow inside the stack at about 3 m (five stack diameters) downstream

of the orifice plate. An instrumentation station is located at 3.05 m

downstream of the orifice plate to measure temperature, velocity and

gas concentrations (CO, CO

2

, 0

^ and total hydrocarbon) of the stack

gases.

In the room fire tests conducted, the total heat release rate of

the heptane spray fire located inside the test room was derived from

the measurements of the calorimeter, using the carbon balance method.

The convective heat leaving the room opening was determined from the

stack gas temperature and velocity. In order to determine the heat

loss rate through the walls and the ceiling, surface heat flux gages

and surface thermocouples have been installed on the ceiling and walls.

In the sprinklered fire tests with constant heptane consumption rates,

a steady-state condition occurred after a period of sprinkler operation. During steady state, the heat absorption rate of the sprinkler

spray was obtained by the difference between the heat release rate of

the fire and the sum of 1) the heat loss rates due to heat transmission

through the ceiling and walls, and 2) the convective and radiative heat

losses through the room opening. It is expected that a correlation

will be established between spray cooling ability (heat absorption rate

of the spray) and the variables: fire size, water discharge rate, and

median drop size of the spray.

To investigate the thermal responses of sprinkler links, four sets

of simulated links have been installed underneath the ceiling, one set

adjacent to the sprinkler nozzle, the other three at 2.44, 3.05 and

3.66 m from the nozzle. Each link set consists of three brass disks of

different thermal sensitivities. A total of 46 gas-temperaturemeasuring thermocouples have been installed for detailed mapping of

ceiling gas temperatures and vertical room temperature profiles. In

addition, five bidirectional flow probes have been mounted to measure

ceiling flow velocities.

Based on detailed mapping of ceiling gas temperatures and velocities, an attempt will be made to develop a ceiling gas flow model for

the flow prior to sprinkler operation. Employing this model, the

thermal responses of simulated sprinkler links before sprinkler actuation will be predicted.

The effects of fire size, water discharge rate, and median drop

73
size on the thermal responses of remote links after sprinkler operation

will be investigated. Correlations between steady-state link temperature and the variables: heat release rate of the fire, water discharge

rate and median drop size will be developed.

It is expected that the results of the research program will improve the scientific understanding of spray cooling in room fires and

provide useful inputs to fire protection engineering.

Reports and Papers

No reports and/or papers have resulted from this work as yet.

74
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution: Factory Mutual Research Corporation

Grant No. : NB83NADA4046

Grant Title: Experimental Fire and Smoke Verification Data for

Multiroom and Corridor Conditions

Principal Investigator : Dr. Gunnar Heskestad

Factory Mutual Research Corporation

1151 Boston-Providence l\irnpike

Norwood, MA 02062

Telephone: (617) 762-4300

Other Professional Personnel: Mr. John P. Hill

NBS Scientific Officer: Mr. Edward K. Budnick

Technical Abstract:

The objective is to establish data on nultiroom fire situations

with particular emphasis on health care facilities. The data will

be used for testing fire modeling and engineering calculations specifically carried out at the Center for Fire Research. However, the

data will, of course, also become available to the fire research

community at large. A number of fire and related life-safety issues

are to be addressed in the total program: burning rates and

heat-release rates of patient-room furnishings; ceiling jet in burn

room; descent of smoke layer in burn room and buildup of pressure

gradients; escape of smoke through open or closed door to corridor;

propagation of smoke front down corridor ceiling and buildup of

smoke layer; penetration of smoke and toxic gases into patient rooms communicating with corridor through closed or open doors; passage of

smoke through suspended ceilings or ventilation ducting; and

response of sprinklers and fire detectors. Both pre-f lashover and

post-f lashover situations are to be included.

The test facility is now nearly ready for routine testing. It

has been built within FMRC’s large fire test building located at

West Glocester, Ehode Island. Figure 1 shows a layout of the facility with indications of instrumentation. There is a "bum room”

and two so-called "target rooms", each measuring 3.66 m square,

attached to 2.44 m wide x 18.90 m long corridor. Three access doors

to the enclosure are provided, but not shown; these will be sealed

tight during tests. The facility is actually built 3.05 m high,

with a subceiling 2.44 m high, forming a 0.6 m high concealed space

above the subceiling. At some advanced stage of the program, the

75
initially solid subceiling will be replaced with a permeable, suspended ceiling in order to study associated effects on smoke travel

from room to room. Each of the three rooms is provided with a vent

to the outside near floor level. The vent mass flow will be measured, whether it is natural or forced with fans.

Gypsum board on wood studs is used throughout. In addition,

the walls and ceiling of the bum room have been overlain with

Marinite (Johns Manville) to harden against repeated fire exposure

Most of the instrumentation indicated in Figure 1 is fairly

standard, except perhaps the "brass disks" and "turbidimeters." The

brass disks are thin, 25 mm dia. brass discs provided with thermocouples to measure thermal response, simulating heat detectors and

also to provide some measure of the gas velocity when coupled with

the response of^an adjacent thermocouple. The turbidimeters, of

in-house design , measure the turbidity of the smoke at three wavelengths from which can be deduced, with the aid of Mie scattering

theory, a characteristic particle size and particle volume fraction. Eight wall pressure taps are provided for measuring six

pressure differentials, including that between the bum room and the

exterior of the facility.

Three types of fires will be investigated: 1) steady propylene

fires at approximately 50 and 500 kW, using "sandbox" burners; 2)

propylene fires programmed to grow parabolically with time to reach

flashover size in four to eight minutes (sandbox burner under computer control); and 3) naturally growing fires in mattress-size

slabs of foamed polyurethane with potentials for spread to other

fuel elements. Various combinations will be investigated of open

and closed doors, open or closed window to the bum room, natural or forced ventilation in all rooms, and solid ceiling or permeable

suspended ceiling. Closed doors and suspended ceilings will be

carefully characterized for leakage in special tests.

Experiments are expected to continue through April 1985.

J. S. Newman, "Development and Design of a Smoke Turbidimeter," FMRC

0F0R3.RC, July 1982.

76
BURN

ROOM

@-H

tj

c

1 Q

° ro 0

O A J I O A • |OA • i O A. • / I+O 1 o l+o O l+or o

Q

TARGET TARGET

ROOM 2 ROOM 1

A O

^ Fire Source

O Vertical Thermocouple Array (8 Levels)

a Vertical Photometer Array (4 Levels)

+ Ceiling Thermocouple (Imbedded in Ceil. Surf. Layer)

O Brass Disk Under Ceiling (Simulates Heat Detector)

H

Bidirectional Flow Probe Under Ceiling

Eye-Level Sampling of 0

^, CC^, CO — Ionizat ion-Phot oel. Pair of Smoke Detectors • Ceiling Gas Thermocouple

Eye-Level Sampling of C0

2

, CO

T Turbidimeter Under Ceiling

O Wall Pressure Taps (0.39 m From Ceiling)

Fi

?a

r

o 1 * Facllity W±th instrumentation. Corridor measures 2.44 m

x 18.9 m, and each room measures 3.66 m x 3.66 m. Ceiling height is 2.44 m.

77
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution: Factory Mutual Research Corp. , Norwood, MA 02062

Grant No: NB82 NADA 3030

Title: Prediction of Fire Dynamics

Principal Investigators : Raymond Friedman (617)762-4300, ext. 2870

Howard W. Emmons (617)495-2847

Other Professional Personnel: R. L. Alpert

M. A. Delichatsios

J. de Ris

G. H. Markstein

L. Orloff

NBS Scientific Officer: J. Quintiere

Technical Abstract:

The objectives are to improve the scientific understanding of fire

and provide useful inputs to fire safety engineering. The five current

tasks are: develop a computer code for predicting development of a fire

in a building; measure entrainment rates into fire plumes; characterize

flame radiation; correlate distribution of chemical species in pool

fires; and develop a technique for studying transient pyrolysis and

flame radiation of charring fuels.

1.

Prediction of Fire in Buildings

The objective of this task is to examine the ultimate requirements

of a computer program for the spread and decay of a fire in a building - large or small - and to take appropriate steps to move the present

Computer Fire Code program in that direction.

1) The general computer fire code requirements will be discussed

in a series of reports on the various components which must be correctly

predicted by a successful program. These reports will effectively be

chapters in a book on "The Prediction of Fires in Buildings". A tentative outline is given as Appendix 1. The first few chapters will be

completed in this first contract year.

2. The use of CFCV has shown how the physical phenomena of fires

can produce such rapid changes that the numerical algorithm gets into

difficulties. The ignition of target objects can cause very large and

rapid fluctuations of flow through the vents. These fluctuations are

real. They are frequently reported in real fires as wooshes. All

computer codes must be used to seek out the presence of such phenomena

and then efforts must be made to so write the physical equations that

the numerical method will not bomb out but will give a sufficiently

accurate description of the real phenomena.

3. An important phenomenon not yet included in any zone model

computer fire code is the nonsteady ceiling jet. Models which instantaneously produce a hot layer of uniform properties over the entire

ceiling of a room work well for small rooms but badly for large ones.

The nonsteady ceiling jet is responsible for the delay in the spread of

fire down a corridor. The velocity of the advancing front of a ceiling

jet is given by

78
u - /gH (1 ( 1 ) - 6/H) ( 1 - p/p ) 1/2

r a relative to the cold gas in front of it.

If the ceiling jet in a corridor is fed at a rate m at a density p from a fire in a room into which cold air at density p flows at a rate

ra D

, the front velocity and the hot layer depth are given by quadratic

equations while the cold flow out the opposite end of the corridor is

given by

M

= — Mp (conservation of volume) (2)

• • • m m mn where M = M = -

M = ^

R = p/p

a

p Hw/gH , Up Hw/gh , Dp Hw/gH , a a a a

c

f The solutions to the quadratic equations for the velocity, C = , /gH

and depth, A = 6/H, are shown in Fig. 1. Since some of the curves

for m_> 0 (flow into the fire room) have a vertical tangent, we learn

that buoyancy has a limited capacity to move fire gases out of the fire

room.

Appendix

I. Introduction and General Component

(Fire, Plumes, Layers, Vents, Heat

II. Components

1. Fires

a. Growing (slab, line)

b. Pool

c. Burner

d. Crib

e. Wall

2. Extinguishment and Detection

a. Sprinklers

b. Hose Streams

3.

Plumes

a. Point source

b. Line source

c. Area source

and Phenomena

Transfers, Flows, Brands, etc.)

f. Corner

g. Ceiling

h. Furniture

i. Ventilation limited

j . Burn-Out

c. Other agents

d. Detectors

i. Ionization

ii. Photo

iii. Thermal

d. On wall

e. In corner

f. By vent

79
4.

Layers

a. Hot Layer

i. Energy (depth) iv. Composition

ii. Mass v. Ignition

iii

Heat transfer (radiation, vi . Burning

convection) vii. Ceiling jet

b. Cold Layer

i. Mass iv. Composition

ii. Energy (temperature)

iii

Heat transfer (convection, radiation)

c. Ventilation Limited Fire

5. Vents

a. Door or window

b. Sky light or roof holes

c. Forced

6. Walls

a. Solid b. Layered

d. Flow entrainment

e. Flow apportionment

c. Hollow

7.

Building Flows

a. Mean flows

b. Buoyant flows

i. Ceiling jets

ii. Stairwells

c. Ventilation system

d. Shafts

(elevator, wall)

e. Dynamic effects

(sounds and

explosions

)

8.

Wind and Weather

a. Building pressure distributions b. Moisture

III. Phenomena

1. Heating

a. Conduction b. Melting c. Structural failure

2.

Pyrolysis

a. Heat of Pyrolysis

b. Pyrolysis products

c. Arrhenius or pyrolysis temperature

3.

Ignition

a. Arrhenius or ignition temperature c. Spontaneous

b. Pilot d. Hot layer ignition

4 . Burning

a. Heat of combustion e. Layer combustion

b. Efficiency and rate of heat release f. Vitiation

c. Combustion products

d. Flame temperature and radiation

g* Ventilation limited

80
C&ilwc/ Jet Flow Fig»r*. /

81
2. Entrainment in Pool Fires

We have completed the measurements of entrainment rates into turbulent buoyant jet flames, in a 1.2 m diameter enclosure. The main

results are:

1) For turbulent jet fires controlled only by buoyancy, air

entrainment rates into the flames are independent of the fuel supply

rate and increase with the 5/2 power of the distance from the nozzle

exit. This behavior is similar to an expression recommended previously

by Zukoski ; however, our measurements provided an entrainment rate by a factor of two smaller than the previous measurements by Zukoski. This

discrepancy was ascribed to two factors: 1) the difference in the fire source sizes (200 mm in Zukoski compared to 12, 23, and 30 mm dia in the

present study); and b) the absence in our experiments of large-scale

toroidal structures in contrast to Zukoski's pool fires.

2) If one decreases the nozzle size (from 23 mm to 12 mm dia for

20-50 kW flames) the increased nozzle momentum delays (stabilizes) the

buoyancy driven transition to turbulence causing the entrainment to

depend slightly on the total heat release, while its variation with

height is similar to the larger (23 mm) nozzle but with a virtual origin

above the nozzle exit. The entrainment rates for a 30 and a 23 mm

diameter buoyant jet fire coincide with each other.

3) Based on the present experimental results, we have shown that

existing integral models for turbulent burning require significant

modifications in order to include the apparent nonequilibrium nature of

turbulence in fire plumes. A possible modification has been suggested

which takes into account the variation of turbulent velocity intensities

along the fire.

Entrainment rates have also been measured for a 190 mm diameter

propane pool fire in the 1.2 m diameter enclosure. The entrainment

rates agree with Beyler's, which were obtained using a different technique. Both Beyler's and FMRC's results for both pool and jet fires were correlated by a single curve of entrainment relative to stoichiometry versus height plus fire source diameter all divided by heat

release to the two-fifths power.

3. Radiation from Flames

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 of

total radiant emission from turbulent and laminar buoyant diffusion

flames, with particular emphasis on the relationship between radiant

emission and sooting tendency of the fuel. For buoyant turbulent flame

jets, the radiative fraction of total rate of heat release is a convenient measure of radiant emission, since it is independent of fuel flow

rate over a wide range of flow rates and thus primarily a function of

fuel chemistry. The sooting tendency in diffusion flames is customarily

82
measured by the flame height of a laminar diffusion flame (or, equivalently, the fuel mass flow rate) at which soot just begins to issue from

the flame tip (smoke point). In the present work, a linear correlation

between radiative fraction of buoyant turbulent flame jets and smokepoint flame height was established for a variety of hydrocarbon fuels of

widely varying sooting tendency. It may thus be possible to predict

radiant emission of fairly large turbulent diffusion flames from

measurements of the smoke point, performed with small laminar flames.

The results further indicated that for fuels of high sooting tendency,

the radiative fraction saturates at a value of about 42 percent.

In order to gain a deeper insight into the relationship between

radiation and sooting tendency, it seemed indispensable to perform

measurements on laminar diffusion flames over a wide range of experimental conditions. Work thus far has been performed with pure hydrocarbon fuels , binary fuel mixtures and nitrogen-diluted fuels burning in

air, as well as pure or nitrogen-diluted fuels burning in atmospheres

with reduced or increased oxygen fraction.

With laminar flames, radiative fraction is not constant but

increases with increasing fuel flow rate. However, one obtains simple

results for mixtures of olefins and with butadiene, whether pure, in

binary mixtures, or diluted with moderate amounts of nitrogen. For all

these fuels burning in air, at the smoke point the total loss fraction,

consisting primarily of radiant fraction augmented by a small constant

heat loss (about 3 watt) to the burner, had a value of about 30 percent,

independent of fuel composition. Analogous results were also obtained

with increased or reduced oxygen concentration in the atmosphere, but

under these conditions the total loss fraction at the smoke point increased with increasing ambient oxygen concentration. Furthermore, for

the olefins and butadiene a linear mixing rule for the smoke point,

previously found by other investigators, was confirmed.

However, with binary mixtures of olefins and paraffins distinct

deviations from these results are encountered. In view of the important

influence of flame temperature on sooting tendency, it was suspected

that the deviations were at least in part caused by flame temperature

variations. Therefore, future work will be performed under conditions

where the adiabatic flame temperature is held constant for a variety of

fuel mixtures. To maintain constant flame temperature, varying amounts

of nitrogen diluent will be added to the fuel mixtures and/or the atmosphere. In addition we will control the adiabatic flame temperature by

preheating the fuel.

It is also planned to perform further measurements on turbulent

flame jets, and to extend the study to turbulent vertical-wall flames.

4. Chemical Modeling of Large Pool Fires

In a continuation of earlier work, local chemical species concentrations have been measured in propane pool fires of 38 cm and 76 cm diameter, at combustion rates from 50 to 283 kW. Burner lip size has

also been varied. The axial composition data are linearly correlated

when the normalized mixture fraction, u, (averaged over the atomic species C, H, 0, and N) is plotted on log paper against (Z + D + 5L)/Cr' , where Z is the height above the burner surface, D and L are the diameter

83
and lip height of the burner, and Q is the heat release rate. The

normalized mixture fraction, £, is the average of

(Mf - Mioo )/(Mi £ - M-^oo) where and are the mass fractions of

element C, H, 0 or N at the sampling point, in the injected fuel, and in

the ambient. For these large pool fires burning in the open, the slope

of the correlation is -7/2. However, similar correlations for buoyant

turbulent jets and small pool fires burning in our 1.2 m diameter

enclosure having a very quiescent atmosphere indicate a -5/2 power

decay. Two possible explanations for this significant difference in

decay rate are (1) the "open" fires are more turbulent due to vorticity

in the ambient, and thus entrain air at a greater rate; and (2) the

mixture fraction is "smeared" laterally to a greater extent in the

meandering "open" fires.

The success of the (Z + D + 5L)/Q

' parameter is consistent with

Froude modeling coupled with a virtual source relationship closely

related to that obtained by Heskestad.

5. Flame Radiation from Charring Fuels

A pyrolysis chamber has been designed for producing fuel vapors from

charring combustible solids in a horizontal configuration up to 30 cm

square. An electrically heated radiant panel and inert purge gas will

be used. The effluent will be burned as a turbulent, buoyant jet diffusion flame. The time -dependent total and radiative heat release rates

of this flame will be measured. A range of charring fuels will be

studied.

Future Plans

The computer fire code will continue to be extended. The nonsteady

ceiling jet model will be incorporated into the computer fire code.

Numerical instability problems in the model will be traced down to their sources and corrected rather than relying on ad hoc fixes. The next

items to be added to the fire code are the burning of the hot layer,

flames out the door into the next room, temperature and composition of

the cold layer, and buoyant flow throughout a building.

A program to measure the effect of ambient vitiation and fuel

diluents , on radiative properties of buoyant turbulent jet diffusion

flames will be undertaken. Also, mean species concentrations will be

correlated. Radiative fraction of heat release rate, Schmidt temperatures, and absorption cross-sections will be simultaneously and nonintrusively measured. Jet centerline mean species concentrations will

be obtained with a constant mass flow sampling probe. The ambient can

be reduced to 15% using steam addition plus combustion products. The

fuel itself can be diluted with CC^ or steam.

A program will be initiated to measure the radiant fraction of heat

release rate for gaseous-fuel vertical wall fires . Concurrently, similar measurements will be made on pool and jet fires with inerts added at

dilution ratios predicted by theory so as to simulate the cooling effect

of the wall in a wall fire. Radiative characteristics of narrow horizontal slices will be measured as well as the overall radiation from

wall fires, and results compared with theory.

The pyrolysis chamber described above will be used to measure

transient pyrolysis properties of charring fuels and the radiant heat

84
release fraction xR

of their burning pyrolysis products. In addition

to xR

> measurements will be made of: sample surface temperature,

pyrolysis vapor temperature, mass loss, and chemically determined heat

release rate, all time-dependent, for various imposed heat fluxes.

Results will be interpreted in terms of "equivalent" transient pyrolysis

properties and the "normal soot point" of the pyrolysis gases. Results

should be useful in predicting flame spread and burning rates in various

use situations from flammability properties.

Technical Reports and Publications

1. Markstein, G.H., "Soot Formation, Radiant Emission and Absorption in

Laminar Ethylene and Propylene Diffusion Flames," Technical Report

No. RC83-BT-6, June 1983.

2. de Ris, J. , "Flammability Testing: State-of-the Art," Paper presented at the Seventeenth Asilomar Conference on Fire and Blast

Effects of Nuclear Weapons, Monterey, CA, Technical Report

No. RC83-BT-7, June 1983.

3. Delichatsios , M.A. , "A Scientific Analysis of Stored Plastic Fire

Tests," Fire Science and Technology, Vol. 3, No. 2., pp. 73-103,

1983.

4. Delichatsios, M.A. , "Flame Heights in Turbulent Wall Fires With

Significant Flame Radiation," Paper presented at the NBS Center for

Fire Research Annual Conf., Washngton, D.C., August 23-25, 1983,

Combustion Science and Technology, in press, 1984.

5. Markstein, G.H. "Measurements on Gaseous-Fuel Pool Fires With A

Fibre-Optic Absorption Probe," Paper presented at the NBS Center for

Fire Research Annual Conf., CST, Washington, D.C. August 23-25, 1983

Combustion Science and Technology , in press, 1984.

6. Alpert, R.L., "Pressure Modeling of Fire Growth on Char-Forming and

Laminated Materials," Technical Report RC83-BT-11, December 1983.

7. Delichatsios, M.A. , "Entrainment Measurements in Turbulent Buoyant

Jet Flames and Implications for Modeling," 20th International Symposium on Combustion, Univ. of Michigan, Ann Arbor, MI, Aug. 12-17,

1984.

8. Markstein, G.H., de Ris, J. , "Radiant Emission and Absorption By

Laminar Ethylene and Propylene Diffusion Flames," 20th International

Symposium on Combustion, Univ. of Michigan, Ann Arbor, MI,

August 12-17, 1984.

9. Markstein, G.H. "Relationship Between Soot Point and Radiant Emission From Buoyant Turbulent and Laminar Diffusion Flames," 20th

International Symposium on Combustion, Univ. of Michigan, Ann Arbor,

MI, August 12-17, 1984.

85
10. Most, J.M. , Sztal, B. , Delichatsios , M.A. , "Turbulent Wall Fires - LDV and Temperature Measurements and Implications," Second International Symposium on Applications of Laser Anemometry to Fluid

Mechanics, Lisbon, Portugal, July 2-4, 1984.

11. Delichatsios, M.A. , "Modeling of Aircraft Cabin Fires," Report

No. 0H0J2.BU, June 1984.

12. de Ris J. , Markstein, G.H., "Estimated Particulate Emissions from

Large Urban and Forest Fires," Technical Memorandum, June 1983.

86
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution: Harvard University

Grant Number : 60NANB4D0010

Grant Title : Prediction of Upper Layer Composition in Transient

Compartment Fires

Principal Investigator : Professor Howard Emmons

Division of Applied Science

Harvard University

Cambridge, MA 02138

Other Professional Personnel : Dr. Craig Beyler (Postdoctoral Fellow)

NBS Scientific Officer: Mr. Richard Bukowski

Technical Abstract :

The objective of this project is to establish methods and data

required to predict the composition of a hot gas layer formed by the

collection of products of combustion from a burning object. The

major focus of current work is the determination of the mass of major

chemical species produced per unit mass of fuel volatilized for a range of fuels and ventilation conditions.

It has been demonstrated in previous work (1) that the production

rate of major species in buoyant diffusion flames is principally a function of the fuel and the amount of air which is entrained into

the flame below the hot gas layer. In the previous work simple gaseous

and liquid fuels were burned in steady state. In transient fire

conditions where the quasi-steady state assumption is not appropriate,

the production rates will also be a function of the layer oxygen

concentration. Several extensions to the previous work will be

required to provide a general predictive method for hot gas layer

composition in transient fires. In this project the methods used for

gaseous and liquid fuels are being adapted to the burning of solid

fuels found in compartment fires in order both to build a data base

with fuels relevant to compartment fires and to test the generality

of the results of the previous work.

The production rates of CC^, CO, ^0, H , and total hydrocarbons

(THC) ; the consumption rate of oxygen; and tne smoke obscuration

potential are measured and correlated as a function of the ratio of the

fuel volatilization rate to the oxygen entrained below the hot gas

87
layer. Figure 1 shows the results of experiments performed with PMMA

as a fuel. The figure clearly illustrates that at low f uel-to-oxygen

ratios, the production rates are as one would expect for burning in the

open. At higher fuel-to-oxygen ratios, insufficient oxygen is entrained

to burn the PMMA completely. At these fuel-to-oxygen ratios, increased

production rates of products of incomplete combustion (CO, R f and THC) are observed. The plateau in CO and production at large fuel-tooxygen ratios is typical of the behavior observed for gaseous andliquid

fuels. Production rate correlations have also been developed for

polyethylene and wood.

The use of chemical species production rate correlations (like

Figure 1) in compartment fire models will provide improved predictions

of the toxic hazards of the smoke and toxic gases produced in compartment

fires

References

1. Beyler, C.L., Development and Burning of a Layer of Incomplete

Combustion Products Generated by a. Buoyant Diffusion Flame , Ph.D.

Thesis, Harvard University, 1983.

88
02

<Gf1S/GH

FUELXX10')

h2

(GOS/Grt

FUELXX10

%>

C02

(GflS/GM

FUELXX10'

Pnf1A< POLYCAST > PnnA(POLYCAST)

PnPlA(POLYCAST) PfltlAC POLYCAST )

^ 1

PfiriA< POLYCAST ) PnnA(POLYCAST)

FIGURE 1

89
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution: The Pennsylvania State University

Grant No .: 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

315 Mechanical Engineering Building

University Park, PA 16802

Telephone: (814)865-3743

Other Professional Personnel : S.-M. Jeng, Research Assistant

M.-C. Lai, Graduate Assistant

NBS Scientific Officer: Dr. James G. Quintiere

Technical Abstract:

Introduction . The objective of this investigation is to study the

structure and radiation properties of turbulent fires along walls.

The findings can be applied to modeling fires in 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. Noncombusting flows

are considered to provide systematic evaluation of analysis. Various

wall inclinations provide information on stratification which is an important aspect of fires within structures. Both nonluminous and

luminous flames are treated, the former to provide baseline

information on radiation from turbulent flames, the latter due to the

importance of radiation from soot in fires.

During this report period, work concentrated on aspects of the

study which are preparatory for measurements and analysis of wall

fires. This included: predictions of spectral radiation intensities

and radiative heat fluxes for conditions of earlier measurements in

nonluminous axisymmetric fires, measurements of the structure of

laminar flames to be used in state relationships needed for

conserved-scalar analysis of turbulent flames; and measurements of mean and turbulent properties in noncombusting wall plumes along

vertical and inclined walls.

Nonluminous Flame Radiation . During earlier work, measurements

were completed of the structure and radiation properties of round

90
turbulent buoyant diffusion flames fueled with natural gas (largely

methane). Predictions of the structure of these flames were also

carried out, using the conserved-scalar formalism in conjunction with

a k-e-g turbulence model. This approach is based on scalar properties

being only a function of mixture fraction (the fraction of mass which

is fuel) to yield state relationships. The laminar flamelet method

was used to find state relationships, based on measurements in laminar

flames which have been found to yield universal state relationships

for a wide range of flame strain rates and length scales. This tactic

also provided good predictions of measured spectral radiation

intensities for the flames, using predicted mean properties. A

stochastic analysis, which approximately treats effects of turbulent

fluctuations, suggested 20-30$ increases in spectral intensities due

to turbulence, but this difference was difficult to detect since

combined experimental and theoretical uncertainties were of similar

magnitude, c.f. references 1-4, 6 and 7 for details.

During this report period, calculations were extended to predict

total radiative hat fluxes at various locations around the fires.

This involved summing contributions over all wavelengths and

incremental paths through the flames to the radiative heat flux

transducers. A portion of the results are illustrated in Fig. 1.

Agreement between predictions and measurements is reasonably good,

which represents one of the first instances where both structure and

radiation properties have been successfully predicted for buoyant

flames. This work provides the necessary background for similar

analysis of radiation from wall fires, c.f. reference 5 for more

details.

Laminar Flame Structure . The theoretical approach being

developed requires state relationships which are found by measuring

temperatures and species concentrations in laminar flames and then

correlating the results as a function of mixture fraction. A laminar

flame apparatus was assembled and these measurements were carried out

for fuels planned for the wall fire tests, e.g., local natural gas

(largely methane for nonluminous flame tests) and ethene (for sooting

luminous flame tests). The ethene tests included measurements of soot

volume fraction, using methods developed at NBS.

The results indicated that nearly universal plots of temperature

and species mass fractions were obtained irrespective of position in

the flame. Past results suggested similar behavior for methane,

propane and n-heptane; therefore, evidence of the approximate

universality of these plots is growing—strengthening the case for the

laminar flamelet method. An interesting additional finding was that

soot volume fractions also roughly correlate with mixture fraction,

suggesting the potential for eventual treatment of luminous flames in

the same manner as nonluminous flames. This idea will be explored

during subsequent work with wall fires.

Buoyant Wall Plumes . Moving directly from axisymmetric flames to

wall fires represents a large step; therefore, preliminary tests and

91
analysis of noncombusting wall plumes have been undertaken. The tests

involve an 800 x 1000 mm wall which can be inclined 0-60° to introduce

effects of stratification. Initial work has been at the Boussinesq

limit, involving carbon dioxide/air mixtures, having a maximum density

variation of 4J, and injected from a slot at the asymptotic Froude

number to speed flow development. Mean and turbulent velocities and

the Reynolds stress are measured using laser Doppler anemometry (LDA)

Mean concentrations are measured using isokinetic sampling and

analysis with a continuous NDIR detector. However, more useful

measurements of mean and fluctuating concentrations (with potential

for measuring cross-correlations with velocity) are being undertaken

using off-resonance laser-induced fluorescence (ORLIF) based on fluorescence from iodine vapor tracer in the slot flow.

A portion of the results are illustrated in Fig. 2 for a vertical

wall. Streamwise mean and fluctuating velocities and mean concentrations (by sampling) are plotted as a function of distance

from the wall, y, divided by distance above the slot, x, which is the

similarity variable for the outer portion of the flow. Various

distances above the slot, normalized by the slot height b, are considered. The results are qualitatively similar to earlier hot-wire

measurements by Grella and Faeth (1975) in thermal wall plumes, but

are more useful for development of theory due to the increased

reliability of LDA measurements. An unusual feature of these flows

(and wall fires as well) is their thickness, which far exceeds buoyant

natural convection boundary layers. There are also significant

effects of laminarization near the wall due to low rates of turbulence

production near the velocity maximum. These features make the wall

plume an excellent flow for definitive evaluation of buoyant

turbulence analysis—particularly when inclined surfaces are considered to introduce effects of stratification.

Conclusions : The conserved-scalar turbulence analysis, combined

with the laminar flamelet approximation, continues to look encouraging

as a means of predicting the structure and radiation properties of

buoyant flames. The potential for treating soot and luminous flame

radiation in the same manner looks promising as well, from initial

results, but must be studied more thoroughly. The wall plume

experiments are yielding results useful for testing predictions of

turbulence properties for buoyant wall flows.

Subsequent work will involve measurements in strongly—buoyant

noncombusting wall plumes and wall fires, as well as computations to

evaluate methods of analysis.

Reports and Papers :

1. S.-M. Jeng and G. M. Faeth, "Species Concentrations and Turbulence

Properties in Buoyant Methane Diffusion Flames," J. Heat Transfer,

in press.

2. S.-M. Jeng and G. M. Faeth, "Predictions of Mean Scalar Properties

in Turbulent Propane Diffusion Flames," J. Heat Transfer, in press.

92
3. S.-M. Jeng, M.-C. Lai and G. M. Faeth, "Nonluminous Radiation in

Turbulent Buoyant Axisymmetric Flames,” Comb. Sci. and Tech., in

press.

4. S.-M. Jeng, M.-C. Lai and G. M. Faeth, "Infrared Radiation from

Gases in Buoyant, Turbulent Methane Diffusion Flames,” Proceedings

of the Sixteenth Fall Technical Meeting, Eastern Section of the

Combustion Institute, Pittsburgh, 1983.

5. S.-M. Jeng and G. M. Faeth, "Radiative Heat Fluxes Near Turbulent

Buoyant Methane Diffusion Flames," J. Heat Transfer, in press.

6. S.-M. Jeng, M.-C. Lai and G. M. Faeth, "An Investigation of

Axisymmetric Buoyant Turbulent Diffusion Flames: Flow Structure

and Radiation Properties," Report No. NBS-GCR-84-458 , January

1984.

7. S.-M. Jeng, "An Investigation of the Structure and Radiation

Properties of Turbulent Buoyant Diffusion Flames," Ph.D. Thesis,

The Pennsylvania State University, May 1984.

Figure 1. Total radiative heat flux distribution

parallel to the axis of methane flames.
94

Figure

2.

Mean

and

turbulent

structure

of

buoyant

wall

plumes.
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

InstitutionPrinceton University

Contract Number: NB83NADA4007

Contract Title: Flow Field Effects on the Sooting Structure of Diffusion

Flames

Principal Investigator: Irvin Glassman

Professor

Department of Mechanical and Aerospace

Engineering

Princeton University

Princeton, New Jersey 08544

NBS Scientific Officer : Rermit Smyth

Te chnical 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 Wolfhard-Parker 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" diffusion flame

configuration.

95
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 one-dimensional 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,

two-dimensional flow fields do not readily permit the interpretation of soot

behavior in these terms.

Last year results were reported on the effect of varying the oxygen index.

This contract year the primary concern was to determine the effect of oxidizer

velocity. As before temperature, velocities, number density, volume density

and mean particle sizes were measured. The results obtained showed that the

soot loading, represented by the soot volume fraction, was found to decrease

with increasing oxidizer velocity; e.g., 0 = 1.1 x 10 _ 6

, 7.4 x 10 , 5.8 x 10"7 and 3.3 x 10“^ for oxidizer velocities of 21, 38, 58 and 67 cm/sec respectively. The variation in peak measured temperature was very small ( 1907-1927K)

The number of soot particles did not vary significantly within this velocity

range. Maximum particle size decreased with increasing oxidizer velocity as a result of the reduced residence time for coagulation and for surface growth

reactions with fuel pyrolysis product. The specific surface growth rates (JD/S )

,

when examined in terms of particle age, show the typical decrease with time

(age). For velocities of 21, 38, and 58 cm/sec, the rates are very similar. In

the highest approach velocity case, 67 cm/sec, the growth rates are lower than

those of the other cases except very close to the stagnation zone.

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.

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, Paper No. 8, 1982.

Vandsburger, U. , Kennedy, I.M. and Glassman, I., "Sooting Counterflow Diffusion

Flames with Varying Oxygen Index", Combustion Science and Technology 39^, 263

(1984)

Vandsburger, U., Kennedy, I.M. and Glassman, I., "Sooting Counterflow Diffusion

Flames with Varying Velocity Gradients," accepted for publication in 20th

Symposium (International) on Combustion (1984).

96
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY84

Institution : Rutgers, The State University of New Jersey,

New Brunswick, New Jersey

Grant No. : NB83NADA4047

Grant Title : Negatively Buoyant Flows Generated in Enclosure Fires

Principal Investigator : Professor Yogesh Jaluria

Department of Mechanical and Aerospace

Engineering

Rutgers, The State University of New Jersey

New Brunswick, New Jersey 08903

Telephone: (201) 932-3652

Other Professional Personnel : D. Goldman (M.S. Student)

NBS Scientific Officer : Dr. Leonard Cooper

Technical Abstract

The objective of this project is to carry out a detailed

experimental study of negatively-buoyant flows generated in enclosure

fires. In particular, the study considers the free boundary

circumstance of two-dimensional jets of heated fluid discharged

downward, thus giving rise to a negatively-buoyant situation. The study

also considers the flow adjacent to an adiabatic, or isothermal,

vertical boundary, which represents the walls of a room with a fire.

These circumstances arise at various stages In the growth of an enclosure fire. Of particular interest are the downward penetration of

the flow, the entrainment of adjacent fluid into the flow and the

nature of the flow that arises in the region where the flow is

negatively-buoyant, see Fig. 1. Quantitative information on the

penetration depth and on the flow rate is needed in the modeling of the

enclosure fire growth processes, particularly by means of zone models.

The results are to be presented in terms of generalized variables,

employing non-dimensional governing parameters, so as to permit the use of the obtained data for different enclosure dimensions and energy

input values. The results obtained are also expected to be Important

in the analytical work that may be carried out in the future to

consolidate these measurements and, thus, form the basis for an analytical model to simulate these flows.

The experimental arrangement has been completed. Air is sent

through a copper tube, which is heated by means of strip heaters

wrapped around it. A blower with an adjustable flow rate is used for

generating the flow. The copper tube is held vertically above a glass

tank which is 1.5 m high and is 0.4 m x 0.3 m in cross-section. The

97
blower is located at the top of the tube and a diffuser is positioned

at the entrance of the tank. The diffuser spreads out the heated air

flowing through the tube and discharges the air downward into the tank

as a two-dimensional jet, see Fig. 2. Measurements of velocity and

temperature, by means of a hot-wire anemometer and thermocouples

respectively, have indicated a fairly uniform flow in the jet at the

discharge location.

A considerable amount of effort has been spent on obtaining a satisfactory visualization technique. Because of the relatively small

density change across the tank, the shadowgraph and Schlieren

techniques were found to yield a fairly weak flow pattern. We are now using smoke for visualization. The smoke is generated by the

evaporation of mineral oil as It flows through an electrically-heated

steel tube. A dense white smoke is obtained. This smoke may be

Injected at various locations In the tank and has been found to be

adequate for the visualization of the flow. Using this technique, the

downward flow penetration Is presently being studied. We are

Interested in determining the dependence of the penetration on the

input momentum and buoyancy, as characterized by the inlet Reynolds and

Grashof numbers based on the width of the discharge slot and the Inflow

velocity and temperature.

An array of thermocouples for measuring the temperature field has

also been placed In the tank. Some measurements have been taken on the

time-dependent behavior of the temperature and velocity distributions.

We are presently Investigating the approach to steady state at large

time. The jet is presently located at the middle point of the top cover of the tank and will soon be moved adjacent to the walls in order

to study the penetrative effects In that case. A hot-wire anemometer

has also been located In the flow, in order to determine the velocity

distribution. It is found that the flow initially demonstrates a strong dependence on time, eventually settling into a quasi-steady

situation, as the walls heat up. Because of the opening at the bottom,

a steady flow arises finally. The measurements are presently directed

at studying the transient behavior and the approach to steady state.

Once adequate information is obtained on these characteristics, a detailed investigation of the velocity and temperature fields will be

undertaken. These measurements would, therefore. Indicate the downward

penetration of the flow, the resulting entrainment and the effect of

the wall on the flow. Some of the results obtained will be discussed

at the Center for Fire Research Conference In October, 1984.

98
WALL

Fig. 1. Negatively buoyant flows arising in enclosure fires.

Fig. 2. Sketch of the experimental system for the study of negati vely-buoyant

flows generated in enclosure fires.

99
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution : Department of Fire Technology, Southwest Research

Institute, San Antonio, Texas

Grant No.: NB83NADA4015

Grant Title : "Analysis of Hazards to Life Safety in Fires: A

Comprehensive Multi-Dimensional Research Program"

Principle

Investigator : Dr. Gordon E. Hartzell, Director

Department of Fire Technology

Southwest Research Institute

6220 Culebra Road

San Antonio, Texas 78238

Other

Professional

Personnel

Dr. Harold L. Kaplan

Dr. Arthur F. Grand

Dr. Steven C. Packham

Walter G. Switzer

Howard W. Stacy

Deggary N. Priest

NBS Scientific

Officer : Dr. Barbara C. Levin

Technical Abstract:

The overall objective of this research program is to develop

methodology to assess toxicological hazards to human life from the

time course of analytical data as provided by a fire model. The first

year objectives of the program were to assess and select appropriate

animal models and to develop concentration-lethality relationships for

HC1 alone and in combination with CO.

The Animal Model . The investigators for this program completed a thorough review of available data for CO, HCN and HCl administered

both to rodents and to nonhuman primates. Of particular additional

importance were data developed under other funding at SwRI for primate

studies involving HCl and CO. Analysis of the data provided considerable evidence that the rat can be used as a reasonable model for primates with respect to behavioral and lethal sensitivity.

The review of data revealed that Ct product ( ppm-minutes) doses

of both CO and HCN causing incapacitation in rats (as measured by leg

flexion, activity wheel, pole climb, rotarod and shuttle-box paradigms), monkeys and baboons were reasonably comparable. While the Ct

product dose causing a response does vary as a function of exposure

concentration, especially over extended regions of the Ct-response

curve, comparable Ct product doses were found to be behaviorally ef100
fective for CO and for HCN in both rats and primates throughout the

central regions of the Ct-response curves. On the strength of this

broad data base and the similarity known to exist in COHb saturation

dynamics for a wide range of mammals, it was concluded that the rat

could serve as an adequate model for human intoxication from the com- mon narcotic fire gases when comparable responses are involved.

Of critical concern was the relevance of the rat as a model for

primates upon exposure to HCl. "Conventional wisdom" has long dictated a greater sensitivity to acid gases by mouth breathing primates

than obligatory nose-breathing rodents. References citing HCl levels

being dangerous to humans from even short exposures seemed to support

the theory of greater human sensitivity. However, none of the sources

offered primate data in support of the stated dangerous concentrations

for man. From research performed at Southwest Research Institute

(SwRI) under Federal Aviation Administration sponsorship, considerable

similarity was observed in the post-exposure lethal toxicity of HCl in

baboons and in rats. Even massive doses of HCl did not cause incapacitation due to sensory irritation in either species. Doses sufficient

to cause post-exposure respiratory tract damage leading to death were

lower than those required to cause physiological incapacitation. In

consideration of these findings, the rat appeared to be a reasonable

model for estimating lethal doses (ppm-minute) of HCl for primates.

Toxicity of HCl Atmospheres . A major objective of the first

year's work plan was to develop the quantitative relationships involved with the toxicity of HCl atmospheres such that models can be

developed for the prediction of the toxicological effects of HCl when

present in fire gases.

The toxicological effects of HCl can be divided into two major

categories, those resulting from its action as a sensory irritant

during exposure and those resulting in post-exposure respiratory effects. In view of the findings from the SwRI non-human primate

studies, a significant part of this study concentrated on postexposure lethality of rats attributed to varying times of exposure to

HCl in air.

LC^q's for HCl were determined for exposure times of 5, 10, 15,

22.5, 30 and 60 minutes. A plot of post-exposure LC^q's against exposure time is shown in Figure 1. It should be noted that each point on

the curve represents at least five experiments, each using six rats.

Thus, the overall curve was derived from a population of at least 150

subjects

The LC^q as a function of exposure time curve shown in Figure 1 was developed by exposing rats to a "square-wave" constant concentration of HCl. Gas concentrations, of course, do not remain constant in

a real fire or in smoke from laboratory combustion devices. Thus, the

applicability of Figure 1 for the prediction of toxicological effects

from exposure to changing gas concentrations is limited.

A useful concept may be that of expressing exposure dose as the

Ct product (concentration x time) producing 50-percent lethality,

i.e., the LCgO^q. However, the L(Ct)cQ was found not to be constant

over the range of concentrations of HCl studied. The L(Ct)c^Q values

varied from about 80,000 ppm-min for a 5-minute exposure to 16,000 ppm

101
to about 170,000 ppm-min for a 60-minute exposure to 2,800 ppm. This

shows that higher doses (Ct products) can be tolerated if the HC1

concentration is relatively low.

It is of significance that the Ct product for 50-percent lethality (post exposure) of rats lies in the general range of 80,000-

170,000 ppm-min for HC1. Three non-human primates (juvenile baboons)

were subjected at SwRI to exposure doses of HC1 in approximately the same range (150,000 ppm-min, based on 5-, 15- and 30-minute exposure

intervals) without either incapacitation or post-exposure deaths

occurring. However, these exposures were quite severe and, in the

opinion of the investigators, only slightly higher doses would likely

have resulted in post-exposure deaths. Even the doses employed might

have led to post-exposure lethality had medication (antibiotics and

steriods) not have been administered to the animals. From comparable

data between the rat exposures in this project and our non-human primate work at SwRI, it would appear that the rat is, indeed, a reasonable model for primates in so far as pulmonary irritant effects are concerned

Even relatively low concentrations of HC1 act as a sensory irritant which, through a decrease in respiratory minute volume, would be

expected to alter the rate of loading of other toxicants such as CO.

This effect should manifest itself in slower rates of carboxyhemoglobin loading and resulting longer times to incapacitation and death

due to CO within an exposure. Expressed another way, CO should have

higher "apparent" LC^q's and EC^q's in the presence of HC1, under

conditions of equivalent exposure time.

Experimental studies confirmed expectations in part. The presence of 1000 ppm HC1 did, indeed, slow the loading of CO and extend

mean times to effect, with the phenomenon being increasingly more

pronounced at CO concentrations below about 4000 ppm. For 30-minute

exposures, this is in the sublethal, incapacitating range of CO. The

effect of the combination of CO and HCl is barely detectable at the

30-minute LC^q of CO.

To further elucidate these effects of a sensory irritant on the

loading of CO, a body plethysmographic technique was developed for

determination of the respiratory minute volume (RMV) of rats during

exposure. The apparatus, compatible with standard head-only exposures

in the NBS 200-L smoke exposure chamber, provides continuous recording

of respiratory patterns from which respiratory rate and tidal volume

can be derived for calculation of RMV.

Data collected in our laboratory using this technique has been

used in combination with a linear regression formula for COHb saturation rates in rats with very promising results. Verifiable modeling

of effects from respiratory irritants and stimulants during inhalation

intoxication can now be undertaken.

Development of Methodology for the Modeling of Toxicological

Effects . The modeling of intoxication by CO is facilitated by the use

of blood COHb as a measure of body burden. Unfortunately, no such

measure of body burden for HCl and HCN exist. Modeling of toxicological effects of these toxicants, as well as for CO, is being developed

which involves continuous calculation of incremental exposure doses

102
(Ct products) and relating each to that required to produce a given

effect at the particular concentration. The effect, either incapacitation or lethality, would have the greatest probability of occurring

at the time at which the summation of the fractional doses becomes

unity for a given toxicant.

Toxicological modeling based on the concept of summation of fractional doses is not new. The SwRI model differs significantly in the

following ways:

a) Ct products are experimentally determined using animal

models which provide reasonable extrapolation to humans,

rather than being estimated from TLV occupational exposure data.

b) Ct products are not assumed to be constant but, rather,

are expressed as a functon of concentration.

c) Simple additivity of fractional effect doses for combinations of toxicants is not assumed in the SwRI model.

Interactions between toxicants are to be determined

experimentally; otherwise toxicants are treated independently.

103
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FLY 84

Institution: Stanford University

Grant No.: NBS Grant NB 83NAD 4019

Grant Title: The Behavior of Furniture Frames During Fire

Principle Investigator : Professor George S. Springer

Department of Aeronautics and Astronautics

Stanford University

Stanford, California 94305

Telephone: (415) 497-4135

Other Professional Personnel : F.K. Chang (Post Doctoral Fellow)

W.I. Lee (Post Doctoral Fellow)

E. Callius (Ph.D. candidate)

J. Burwasser (M.S. student)

P. Homer (M.S. student)

NBS Scientific Office: William J. Parker

Technical Abstract :

The objective of this investigation is to evaluate the behavior of

furniture frames during fire. In order to achieve this objective tests

are being performed measuring the strengths and deflections of wooden

and plastic furniture frame joints exposed to elevated temperatures.

The time of failure of the joints is also recorded. In conjunction with

the tests a model is also being developed for describing the response

of joints to high temperature environments.

A preliminary series of tests were performed with southern pine.

In these tests the thermal response of southern pine was evaluated by

measuring the mass losses of 3 in. by 2 in. by 3/4 in. specimens exposed

to 75, 160, and 245°C. The mass (weight) losses were recorded as functions of exposure time. The data were compared to the results of an analytical model discussed below. Good agreement was found between the

data and the results of the model, supporting the validity of the model.

Following the mass loss measurements, tests were performed with different types of joints made of southern pine. The geometries of the joints

are shown in Table 1. Each joint was exposed to a constant temperature

of either 100°C, 160°C or 245°C for a predetermined length of time. The

joint was then loaded and the deflection of the joint was measured.

These measurements provided the load versus deflection for each joint,

the deflection at failure, and the load at failure. A total of 532

joints were used in these tests. Attempts are now being made to

104
relate the degradation of the strengths of different types of joints to

the degradation of the strengths of solid corners and bends (top figure.

Table 1) . As will be discussed below, the changes in strengths of

solid corners and bends can be predicted by an analytical model. Thus, once relationships between the strengths of joints and corners and

bends are established, the model also provides the changes in the

strengths of joints exposed to elevated temperatures.

In addition to testing, analytical models are being developed to

simulate the response of corners and bends to elevated temperatures.

The specific goal in constructing the model is to describe the changes

in the thermal and mechanical properties of corners and bends, and to

predict the time of failure. The model is developed in four steps,

a) calculation of the temperature distribution and mass loss inside corners and bends, (b) calculation of the changes in stress and strains

with time, c) estimation of the changes in strength and moduli with

time and, (d) 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

formulated on the basis of the law of conservation of energy, with the

chemical reactions represented by a single step Arrhenius bulk reaction. The calculations are performed for two dimensional geometries.

As was noted above, the results of the model agree well with the mass

loss data generated in this study.

The second part of the model is used to calculate the stresses

and strains in corners and bends. The stresses and strains are calculated using a two-dimensional finite element method of solution of

the governing equations.

The third part of the model provides a means of estimating the

changes in strengths and moduli. This model is based on the hypothesis

that degradation in mechanical properties are related to the mass loss

caused by volatilization of the wood. The validity of this hypothesis

was shown to be reasonable by the results of tests performed with rec- tangular slabs.

The fourth part of the model provides the failure time of corners

and bends during fire exposure. The model relates the applied stresses

to the allowable strength through an appropriate failure criterion.

On the basis of the models a "user friendly" computer code is now being developed. All four steps of the model are incorporated into

this code. The code can be applied to loaded corners and bends exposed

to elevated temperatures, and provides the stresses and strains in the

wood as well as the following parameters, a) temperature distribution

inside the wood, b) mass loss, c) strength loss, d) stiffness loss, and

c) failure time.

Work is now in progress to complete the model and to compare the

105
results of the model to data. It is planned to extend the investigation to higher temperatures and to the study the behavior of joints

formed of plastics.

The data generated and the model developed in this investigation

will provide means of evaluating the response of different types of

furniture frames to fire and of estimating the failure time. This information will help in establishing appropriate endurance ratings for

furniture, and will lead to more fire resistant furniture design and

construction methods.

Reports and Papers :

1. G.S. Springer, F.K. Chang, and P. Homer, "The Behavior of

Furniture Frames During Fire", Report to the Center for Fire

Research, National Bureau of Standards, October 1984.

2. G.S. Springer, M.H. Do and D.A. Stanke, "Mass Loss of and

Temperature Distribution in Southern Pine and Douglas Fir in the

Range 100 to 800°C", _1, No. 4, 271-284 (1983).

3. G.S. Springer, M.H. Do, "Model for Predicting Changes in the

Strength and Moduli of Wood Exposed to Elevated Temperatures",

Jo. of Fire Sciences, _1, No. 4, 285-296 (1983).

4. G.S. Springer, M.H. Do, "Failure Time of Loaded Wooden Beams

During Fire", Jo. of Fire Sciences, _1 , No. 4, 297-303 (1983).

106
Angles:

^ = 60°, 90° , 120°

Grain Orientations: 9 = 30°, 45°, 60°

Fasteners: 2 screws or nails with

and without brackets

Fasteners: 2 screws or nails with

and without brackets

Fasteners: 2 screws or nails

Grain Orientation: 0 = 0° or 90°

107
Fasteners: 2 screws or nails

Grain Orientations: Q = 0° and 90°

Fasteners: 2 screws, 2 nails, or

a single bolt (centered)

Grain Orientation: ^ = 0° or 90°

Thickness: 0.75 in (nominal)

Width: Solid Elbow (first figure) 1.5 in (nominal)

Width: Joints : 3 in (nominal)

108
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Insti tution : TRW

Contract Number : MB82SBCA1662

Contract Title : Modeling of Wind-Aided Flame Spread

Principal Investigator : Francis Fendell

Engineering Sciences Laboratory

TRW Space and Technology Group

Redondo Beach, CA 90278

Telephone: (213) 536-2757

Other Professional Personnel : George Carrier, Harvard University

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.

Flame-propagation rates become particularly significant under wind-aided

conditions; 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 uni nvol ved downwind combustible materials. In contrast, in spread against the wind,

fire advance 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, quasi steady

approximation tends to be inadequate and explicit accounting for temporal

derivatives is required; thus, even the simplest scenarios in wind-aiding

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 cor- rect 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 forced-convection 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 a crucial

109
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). Here, primary attention is to be placed on case (1),

which (for all its difficulties) may be the most straightforward and

tractable of the three cases. Space precludes comments concerning the

other two cases (but see the references). However, before any of the

cases are discussed, some general remarks on formulation are apropos.

2. Formulation . A formulation is sought in which all the significant

phenomena are incorporated in the simplest reasonable form, such that con- vection, 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-Zeldovich 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- layer 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, mo- mentum, and heat in the manner of Oseen; that is, it is possible to 1 ineari ze the streamwi se 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 transpo rt transverse to streaming enta i 1 s nonl inearity . The conventional Shvab-Zeldovich 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) va- por 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 erodes in a forced-convective

flow; this may be owing to loss of mechanical strength such that spalling

110
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 in

the present context, but rather tends to remain thin relative to the

depth of the gas-phase boundary layer and of the pristine-solid thermal

layer (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-Zel dovich 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- sol id 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 Reasarch is noteworthy.

In summary, wind-aided flame challenges modeler to incorporate tractable formulation of charring and radiative transfer in an explicitly un- steady, spatially (at least) two-dimensional problem involving close coupling 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 air stream over

the leading edge becoming hot and vitiated at time zero. 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 ex- tent of slab "involvement" . While knowledge of the progression rates of

these fronts does not constitute a complete solution throughout the threeindependent-variable space, such knowledge does provide the knowledge of

particular engineering significance, and theoretically one can later as- certain meticulous details if one wishes.

Either by use of point-source solution for a second-order parabolic

operator, or alternatively by Weiner-Hopf-1 ike 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 inter- facial 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

to the fact that different algebraic relations pertain to the preheat,

char formation, and char erosion zones. The integral equations are also

ill
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 car- formation front and charerosion front are shock-like 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

Emmons 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 incorporating concepts concerning

the amount and location of soot on the fuel -rich side of the gas-phase

diffusion flame, and its role in radiative transfer; clearly accounting

for this phenomenon now necessitates identification of diffusion-flame

position. It should be appreciated that exceptional solids that gasify

without charring and burn without sooting admit far simpler, selfsimilar

solution throughout the solution domain.

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.

R. D. Fleeter, F. E. Fendell, L. M. Cohen, N. Gat, and A. Witte, (1984),

"Laboratory Facility for Wind-Aided Firespread Along a Fuel Matrix,"

Combustion and Flame, to appear.

112
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

InstitutionUniversity of California, Berkeley

Grant No.: NB83NADA4020

Grant Title : Fire Propagation in Concurrent Flows

Principle Investigator : Professor A. C. Fernandez-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: H. R. Baum

Technical Abstract :

Experimental and theoretical studies of the process of flow assisted fire spread over the surface of combustible surfaces have been

carried out. Research efforts have concentrated on two aspects of this

mode of fire spread: 1) Fire spread in a concurrent forced (or mixed)

flow; and 2) Fire spread along the walls of an enclosure in natural

convection. During this reporting period a series of experiments of

the dependence on the velocity and oxygen concentration of the concurrent forced flow of the rate of flame spread over thick PMMA sheets have

been completed. The results indicate that this form of fire spread is

primarily controlled by heat transfer from the flame to the unburnt com- bustible. Experiments with thin paper sheets are currently underway.

Efforts on the second task have concentrated on the numerical analysis

of the structure of a diffusion flame, established over a burning fuel

surface. The results indicate the existence of significant longitudinal diffusion of heat and species ahead of the flame front. An analysis

on the spread of flames in an enclosure is currently in progress.

Experimental study of concurrent flame spread in a forced flow . Measurements on the rate of flame spread over a combustible flat surface

in a forced gaseous flow of varied velocities and oxygen concentrations

moving in the direction of flame propagation are being taken. The experiments are carried out in a small scale combustion tunnel with a test

section 61 cm long by 12.7 cm wide by 7.6 cm high. The thick fuel specimens are mounted flush in one of the walls of the test section with the

upstream leading edge placed 1.5 cm from the exit plane of the convergent nozzle of the tunnel so that a flat plate flow is generated over

the fuel surface. The thin fuel specimens are mounted in a metallic

frame which is positioned in the middle of the test section to generate

a flat plate flow. PMMA sheets, 1.27 cm thick, and Whatman 3M filter

paper sheets 0.03 cm thick have been used as fuels to represent ther113
mally thick and thin fuels, respectively. The gaseous flow in the tunnel consists of a mixture of O2 and N2 , the flow rates of which are previously metered with critical nozzles. The gas velocity is measured

with a hot wire anemometer and a pitot tube. Surface temperature histories provided by thermocouples embedded at fixed distances along the

fuel surface are used to determine the rate of flame spread. The

spread rate is calculated from the distance between two consecutive

thermocouples and the time lapse of pyrolysis arrival to the thermocouples.

The results of the measurements of the rate of spread of the

pyrolysis front over PMMA sheets shows that the rate of flame spread is

time independent, linearly dependent on the flow velocity and approximately square power dependent on the oxygen concentration of the gas.

The spread rate data can be correlated very well with a parameter deduced from heat transfer models of the flame spread process, indicating

that in the flow assisted mode of flame spread, heat transfer from the

flame to the condensed fuel is the primary mechanism controlling the

spread of the flame. The measurements taken under mixed convective con- ditions on the spread of flames over the surface of thin filter paper

sheets show that the rate of spread of the pyrolysis front depends on time according to a power law. The exponent varies slightly from the

free to the forced convective limit. For forced flow conditions the

flame spread process is practically independent of the velocity of the

flow. Only limited agreement is found between the experiment and the

predictions from the available models of flow assisted flame spread over thermally thin fuels. It appears that this disagreement is due primarily to transient effects caused by the variation of the pyrolysis length,

particularly during the initiation of the flame spread process. Currently we are performing experiments with longer paper sheets at higher

oxygen concentrations to find if a steady state flame spread is reached

and whether the transient effects are the result of pyrolysis length

variations.

Numerical Analysis of a Diffusion Flame Near Its Leading Edge . An

analysis of the fluid mechanical and thermal structure of the leading

edge of a diffusion flame over a pyrolyzing flat combustible surface in

a mixed convective flow has been performed. The analysis considers

pressure variations in the flow, longtitudinal diffusional effects and

finite rate kinetics. Two cases were analyzed, one with isothermal

walls surrounding the burning surface and the other with adiabatic

walls. In both cases the convection was varied from buoyancy controlled

to forced flow controlled conditions. The results of the analysis show

that upstream from the flame leading edge a region of elevated pressure

is generated by the conjunction of the gas thermal expansion (due to

upstream heat transfer from the flame) and the fuel addition in the

pyrolysis zone. The pressure gradients perturb the flow causing its

deflection and deceleration or acceleration. The convective flow in

turn, by hampering the diffusive processes, limits the zone of influence of the flame to regions that are closer to the vaporizing fuel

surface and thereby creates strong temperature and species gradients

near the reaction zone. If the non-combustible upstream surface is

114
isothermal, the low temperatures near the surface cause the reaction to

freeze, and a quenching layer is formed near the surface. The fuel and

oxidizer mix in this layer. However, for the adiabatic case, the

reaction rate is fast, practically up to the surface, and very little

leakage of fuel or oxidizer occurs through the reaction zone.

The descriptions obtained from this analysis of the processes

taking place in the vicinity of the leading edge of the flame are very

useful for the explanation of a number of experimental observations of

the gas flow pattern and temperature distributions in stationary and

slowly spreading diffusion flames. Of particular interest are the re- sults in the vicinity of the pyrolysis front where finite rate kinetics

are important. It is found that there is a considerable longtitudinal

diffusion of heat and mass in this region and that a quenching layer

exists near the surface. The reaction rate is very small in the

vicinity of the solid surface because the surface temperature is relatively low, and the rate of the chemical reaction is very. sensitive to

temperature. The small reaction rate permits the leakage of oxygen

through the reaction zone, which, in conjunction with the upstream

diffusion of fuel vapor, forms a region upstream from the pyrolysis

front where a mixture of fuel vapor and oxidizer is present. This result has a relevant impact on the description of the controlling mechanisms of flame spread in opposed flows, a subject that has been controversial for some time. It supports a mechanism of flame spread recently proposed by Ray and Glassman (Combustion Science and Technology, 32,

33, 1983) in which a premixed flame generated by the upstream diffusion

of fuel vapor leads to the diffusion flame generated by the burning

surface.

Free Convection Flame Spread in Enclosures . A numerical analysis

of the free, flow assisted, spread of flames over the surface of a thick combustible material. in a vertical wall-ceiling geometrical configuration is being carried out. In order to reduce computing costs, the

gas and solid phase analyses are uncoupled by means of an isothermal

wall condition at the gas/solid interface. This approximation is based

on experimental information and has shown positive results in previous

analytical studies of related problems. The gas phase analysis is also

treated as quasi-steady, because the transport processes in the gas are faster than the rate of spread of the pyrolysis front. Once the

analyses for the two phases are uncoupled, the flame spread process is

solved using a leapfrogging approach. The gas phase equations are

solved for increasing lengths of the pyrolyzing region, and the flame

length and heat flux at the interface are calculated for each pyrolysis

length. This information is used as boundary conditions for the numerical solution of the solid phase, transient, energy equation. The rate

of spread of the pyrolysis front is obtained from the calculated temperature profiles by imposing the condition that at the pyrolysis front

the surface temperature is equal to the evaporation temperature of the

solid. The current results seem to agree qualitatively with the experimental results. A major problem with this analysis is the high computer

costs associated with the numerical calculations. At present we are searching for ways to reduce the time currently required to run the

115
computer program.

Reports and Papers

Mao, C.-P, Femandez-Pello, A. C. and Pagni, P. J., "Mixed Convective

Burning of a Fuel Surface with Arbitrary Inclination," Journal of Heat

Transfer, (in press).

Fernandez-Pello, A. C. , "Flame Spread Modeling," Combustion Science and

Technology, (in press).

Mao, C.-P, Kodama, H. , and Fernandez-Pello, A. C. , "Convective Structure

of a Diffusion Flame over a Flat Combustible Surface," Combustion and

Flame, (in press).

Loh, H. T. and Fernandez-Pello, A. C. , "A Study of the Controlling

Mechanisms of Flow Assisted Flame Spread," accepted for presentation at

the 19th Symposium (International) on Combustion, to be held at Ann

Arbor, Michigan, August 12-17, 1984.

116
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution ; University of California - Berkeley

Grant No. : 60NANB4D0018

Grant Title : Flame Radiation

Principal Investigator : Professor Chang-Lin Tien

Mechanical Engineering Department

University of California

Berkeley, California 94720

Telephone: (415) 642-0877

Other Professional Personnel : M. A. Brosmer (Ph.D student)

K. Y. Lee (Ph.D student)

Z. Y. Zhong (Post Doctoral)

NBS Scientific Officer : Dr. Takashi Kashiwagi

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 research approach aims at developing approximate formulations by systematic experimentation and analysis of the fundamental

aspects of the problem. The present research is focused on two primary

topics: 1) 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 the determination

of radiation absorption in a thin non-isothermal layer composed of these

gases.

Radiation Properties 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. The radiant energy must pass through a thin gas layer which

is composed of numerous species which evolve from the fuel surface, and

attenuate the incoming energy. These gases, which are primarily hydrocarbons, therefore strongly influence the ignition and combustion process. A combined analytic and experimental research effort is 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 include methyl methacrylate (C HgO^), propane (C_Hg), propylene (C^H^), ethane (C^Hg), ethylene (C^H^j, acetylene

(C^H^), and methane (CH^). Infrared measurements are being made for 1 atm. pressure and a temperature range of 300 to 900 K. The spectral

absorption data is used to evaluate the spectral mean and total band

117
properties. The total band properties are then used to specify the gas

emissivity. Results have thus far been obtained for both methane and

propylene. Typical absorptivity and emissivity curves are shown in

Figs. 1 and 2 for propylene for an effective pressure of one. The ana- lytic portion of this project is then to develop a simple modeling

scheme to specify the overall absorption characteristics of the entire

infrared region. A preliminary model has been developed which successfully groups the primary infrared bands of HO, CO , CO, and SO and

accurately predicts the radiation behavior, it will be applied to the

hydrocarbon data in an effort to describe the infrared radiation characteristics of the gases.

Radiative Energy Attenuation by a Non-Isothermal Smoke Layer . One

of the most important elements for accurate determination of the energy

feedback from the flame is the radiation blockage due to the pyrolyzed

gaseous and particulate components in the smoke layer. Radiation blockage by a soot layer has been analyzed, and will be extended to include

the effects of hydrocarbon gases. It is found that the blockage effect

may be significant even in small scale fires for a sooty polymer fuel

such as polystyrene( PS) . The information on radiation blockage has been

utilized to investigate the effect of radiative heat attenuation on the

mechanisms of condensed fuel ignition. With the inclusion of blockage,

predicted ignition delay time and fuel surface temperature history are

in better agreement with experimental data as compared to previous analyses. The shift of ignition delay time due to blockage is presented in

Fig. 3* It can be noted that the blockage effect is more pronounced as

the heat flux and soot content of the system increase. The assumption

of radiative equilibrium has been relaxed in the study of cold wall

flame-quenching to include gas phase conduction. Using the singular

perturbation technique, the quenching distance has been determined as a function of various physical properties. It has been found that the

quenching distance tends to increase as the heat source intensity and

optical thickness of the system decrease. Furthermore, the fuel surface

emissivity is of minor importance in determining the quenching distance.

Reports and Papers :

1. M. A. Brosmer and C. L. Tien, "Infrared Radiation Properties of

Methane at Elevated Temperatures," to be submitted for journal publication .

2. K. Y. Lee, Z. Y. Zhong and C. L. Tien, "Blockage of Thermal Radiation by the Soot Layer in Combustion of Condensed Fuels," to be

presented at the Twentieth Symp. (Int.) on Combust., August (1984).

3. K. Y. Lee and C. L. Tien, "Radiation-Induced Ignition of Condensed

Fuels Including Effects of Radiation Blockage," submitted for journal publication.

4. K. Y. Lee and C. L. Tien, "Flame Wall-Quenching by Radiation and

Conduction in Combustion of Condensed Fuels," to be submitted for

journal publication.

118
SPECTRAL

ABSORPTIVITY

.600

Fig. Spectral Absorption of the IMS cm* 1

, 1647

cm"' and 1 8 30 cm"' Bands at 300 K, 550 K and

300 K. Fig. 2 Total Emlssivity of Propylene Based on

the 3.4. 5.5, 6.1 and 6.9 u Bands with

an Effective Pressure of One.

Fig. 3 Ignition Delay Time vs. Radiative Heat Flux Displaying the Associated Shift due to the 31ockage Effect.

119
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution ; Lawrence Berkeley Laboratory, University of California,

Berkeley

Grant No.: NB 80 NAGE 6839-3

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)

James A. Ang (Ph.D. Candidate)

Valerie Lyons (Ph.D. Candidate)

NBS Scientific Officer: Dr. William Pitts

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 within a compartment and its subsequent propagation

throughout a structure. Our emphasis this grant period has been on flame radiation and its most important and least known parameter, fv

, the soot volume fraction within the flame, f is defined as the v volume occupied by soot per unit of flame volume. Previous reports

have described a multiwavelength laser extinction technique for in

situ measurement of the local flame f^. The full Mie theory, Lee and

Tien optical properties and a two-parameter size distribution are assumed. Alternative simplifying assumptions have been shown to

significantly overestimate f^.

The soot particles have mean diameters, d, ~ 50 nm and

9 -3

concentrations, No, ~ 10 cm . The mean free path of the gas

A, is ~ 500 nm so the particle Knudsen numbers are Kn= \/d~ 10 and

the flow field around the soot particle is free molecular. This

produces strong convective coupling with the gas, i.e., the effective

3 / 2 heat transfer coefficient, h, is ~ 10 W/m K. The soot temperature

is locked to the gas temperature within + 0 /- 5 K, with the larger

negative range due to particle radiative emission. Surface reactions

120
involving C0 2

, H

20, OH and C

2

H

2

all appear to have insignificant

effects on T

g

. A separate consequence of the high Knudsen number is

the need to include thermophoretic forces in particle trajectorycalculations.

Since the particle temperature is the gas temperature, the sooty

gas can be treated as a single radiating medium and the free flow

boundary layer equations can be solved including radiation explicitly.

The nonadiabatic flame temperatures ( K) from these calculations at 4 cm downstream of the leading edge are shown in Table I.

Table I. Flame Temperatures and Soot Parameters

Toluene Cyclohexene Octane Cyclohexane Heptane PMMA

TA fl 2266 2287 2225 2242 2203 2075

T . ad 2343 2307 2233 2249 2208 2131

%C to soot 15 3.3 1.5 1.0 0.5 1 .0

T

exper

2077 2077 2047 2044 2009 1943

T Dead 1972 1972 1946 1943 1913 1856

E

(kcal/mole)

- 50.2 52.9 54.8 59.4 53.5

A(GHz) - 0.15 0.26 0.37 1 .1 0.8

Only toluene , cyclohexene and PMMA show significant nonadiabatic

effects on the flame temperature at these small scales. The 60 K

drop for PMMA is due to radiant emission from the pyrolyzing fuel

surface, while the 80 K drop for toluene and the 20 K drop for

cyclohexene are due to soot emission. The remaining fuels show less

than 10 K drops due to radiation, indicating that at this scale in

air, radiative effects can be neglected in calculating these flow

fields. This is supported by the small amount of carbon converted to

soot for these fuels as shown in the third row of Table I. A

comparison of measured and calculated temperature profiles across the

boundary layer is shown in Fig. 1 . The experimental temperatures

have been corrected for radiation losses from the bead. The peak

measured temperatures, T^eaci, and the corrected values, TeX p er , are also given in Table I.

In addition, calculated velocity fields were used to estimate the

time rate of change of the soot volume fraction along particle

trajectories, f

y# The data were fit with

121
Corrected Exper i men t a I an^l Theoretical Prof i le for n-Heplar\e at 4 cm downstream

Figure 1

°K

-1

Figure 2

122
a

fv » - if

v

u As

A exp (-E/RT) Y

f v

where s is the displacement on a trajectory, u is velocity, is

fuel mass fraction, the bar indicates mean values on As and E and A are parameters, given in Table I. Toluene was so sooty that complete

attenuation occurred and data were limited to a short region too close

to the leading edge to permit determination of E and A. Good

linearity for a = 1 and b = 0 is shown for two sample fuels in Fig. 2.

In the next grant period, existing forced flow fv data will be

analyzed. We will explore perturbation methods incorporating

radiation, finite chemical kinetics and Le * 1 effects in combusting

boundary layer calculations during Dr. Howard Baum’ s stay in our department as Springer Professor of Mechanical Engineering during the

Spring Semester, 1985.

Reports and Papers :

1. P.J. Pagni, "Materials Fire Properties and Test Methods," in

Proceedings of the Seventh Joint Meeting, United States-Japan

Natural Resources Panel on Fire Research and Safety , 24-28 October 1983, Washington, D.C., National Bureau of

Standards, 1984.

2. C-P. Mao, A.C. Femandez-Pello and P.J. Pagni, "Mixed Convective

Burning of a Fuel Surface with Arbitrary Inclination," Journal of

Heat Transfer, Trans. ASME, Series C , 106, 304-309, 1984.

3. R.A. Beier, P.J. Pagni and C.I. Okoh, "Soot and Radiation in

Combusting Boundary Layers," to be published in the Emmons

Special Issue of Combustion Science and Technology

(September 1984).

4. N. Alvares, K. Foote and P.J. Pagni, "Forced Ventilation

Enclosure Fires," to be published in the Emmons Special Issue of

Combustion Science and Technology (September 1984).

5. P.J. Pagni and C.I. Okoh, "Soot Generation within Radiating

Diffusion Flames," presented at the Twentieth Symposium

(international) on Combustion, Ann Arbor, MI., August 12-17,

1984. Also Report LBL-17391 , February 1984.

123
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution : University of Dayton Research Institute, Dayton, Ohio

Grant No. : NB83NADA4056

Grant Title : Mathematical Modeling of Furniture Fires

Principal Investigator : Nicholas A. Engler

Senior Research Physicist

University of Dayton Research Institute

300 College Park - JPC 200

Dayton, Ohio 45469

(513) 229-3921

Other Professional Personnel : Mark A. Dietenberger,

Associate Research Physicist and Ph.D. student

NBS Scientific Officer : Dr. Vytenis Babrauskas

Technical Abstract :

The current objective of this effort is to formulate a practical

mathematical model of furniture fires. The aim is to develop a method

that will predict the growth and decay of a furniture fire based upon

data obtained from bench scale testing of various construction

materials. These bench scale tests utilize fire test devices such as the National Bureau of Standards (NBS) Cone Calorimeter, and the NBS

lateral flame spread apparatus. The present research is focused on two analytical developments: (1) The structure analysis of the furniture fire model consisting of three main modules—the Flame Structure

and Radiation Module (FSRM), the Ignition and Flame Spread Module

( IFSM ) , and, the Local Burning Rate Module (LBRM) , which provides the

heat release rate of the burning furniture; and (2) The calculation of

net radiative heat fluxes from 3-D gray flames to surrounding 3-D gray

objects achieved with a practical zonal radiation analysis which evaluates the exchange factors among finite flame volumes and finite

object surface elements.

Structure Analysis of the Furniture Fire Model . The IFSM and

LBRM modules were analytically developed in a straight-forward

fashion. The IFSM module begins with a surface temperature model of a virgin furniture surface element given the input of local radiative

heat flux and the material properties. The next step is to determine

if the surface element has ignited, and, if so, to identify a region

124
of the surface element as ignited. The flame spread rate equations

for both thermally thin and thick materials and an input of the adjacent flame radiative heat flux distribution near the flame front are used to model a growing burning (or pyrolysis) region. In the LBRM

module for a burning surface element, a model for the surface temperature and emissivity, and for the local pyrolysate rate, is utilized and uses as input the local radiative heat flux. The burning

material thickness and the burning rate of the surface element is

obtained from the pyrolysate rate. The models contained in the above

two modules were available in the literature and the numerical methods were developed in this work.

The FSRM module, however, proved to be much more difficult to

develop. In attacking the FSRM problem, the module was divided into

two submodules, one describing four different types of fire structures and merging them into an overall furniture flame shape, and the

other describing the furniture thermal radiation. These submodules

are designated the "Fire Structure Submodule" and the "Furniture

Thermal Radiation Submodule."

This work has examined criteria for fire structure identification of four basic fire types: tall pool, short pool, wall, and

corner fires. The various fire structure models available in the

literature were reviewed, and the final selection of these models will

be contingent upon the development of the furniture thermal radiation

model. The flame merging model, a part of the fire structure submodule, was adapted to geometry other than flames from the two

separate horizontal slabs. The furniture thermal radiation model that

was selected, was chosen because of its modularity feature and for its

ability to incorporate exchange factors already obtained for compartment fires.

Practical Thermal Radiation Model for 3-D Gray Flames and

Objects. The rationale behind this model selection and development is

that the modeling of a furniture fire, and the modeling of compartment

fires which are being generalized into more zonal divisions, will

require a three-dimensional representation of thermal radiation.

Typical values of furniture surface emissivities and of the flame

absorptivities imply gray body assumptions. The net radiative heat

fluxes need to be as accurate as possible, because they directly

determine the flame spread rate and surface burning rate. The calculations of net radiative heat fluxes, however, must be practical if

they are to be used in modeling time-dependent fire growth.

The zonal radiation analysis begins with the exchange factor

method described by Larsen, which is similar to Hottel's zone method,

for an enclosure with isothermal, optically thin, and elemental gas

volumes. The exchange factor method was extended to isothermal,

moderately optically thick, and finite gas volumes by the following

procedures. The gas volume was treated as being moderately optically

125
thick by using the mean beam length theory in deriving the flame

emissivity. Orloff's procedure to multiply the flame emissivity by

the configuration factors of optically thick gas volumes was used in

the exchange factors evaluation. Although Orloff only described the

configuration factors for a target surface far from a radiating gas

volume, which is the sooty flame, in this work the configuration factors were extended to distances close to the radiating gas volume.

The flame emissivity as a function of total flame absorptivity, flame

volume, and a reference flame projected area was also modified for

agreement with theoretical and experimental results for radiation from

the cylinder and conical gas volume at different distances and at different optical thicknesses. The resulting zonal radiation analysis is

being used to demonstrate a simple cylinder flame on the seat of a simple chair. The enclosure of a room is being taken into account by

using the radiation conservation laws derived by Larsen.

In conclusion, the NBS at present uses expensive full-scale

experiments to assess the fire hazards of various types of furniture.

This mathematical modeling of furniture fires will be a useful, analytical complement to these full-scale tests, and will hopefully aid

engineers in designing rooms and furniture to reduce fire loss.

Reports and Papers: none

126
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution: University of Florida

Grant No .: NB81NADA2057

Grant Title . Network Models of Building Evacuation:

Development of Software System - Year Three

Principal Investigator(s) : Thomas M. Kisko and Richard L. Francis,

Ph.D.

NBS Scie nt if ic Officer : Bud Nel son

Technical Abstract:

This abstract summarizes the efforts of the third year of a 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 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 estimated by

utilizing the dimensions of the building and the distribution of

people in the building at the time of the evacuation.

When 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

127
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 or 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.

128
1 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

RUM - RUN MODEL

EXAM - TERMINATE EXECUTION OF EVACNET

HELP - WHENEVER YOU HAVE QUESTIONS

ENTER CODE OF REQUESTED ACTION

L J

FIGURE 1 - EVACNET+ MASTER OPTION LIST

The first year's effort of the EVACNET+ project involved the

development of the majority of the EVACNET+ computer program. 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 current year of the project involves research on extensions

to EVACNET+. The list below summarizes some of the areas that are being investigated.

(a) Interface with other fire models.

(b) Ability to model the effects of smoke and fire spread.

(c) A model-controlled adjustment option.

(d) Heuristics for determining an upper bound on evacuation

time.

(e) Heuristics for approximate solutions

(f) A simulation based solution procedure.

(g) Expanded model input and editing procedures.

(h) A results data base analysis system.

We are also implementing EVACNET+ on a personal computer. An

MS-DOS machine was selected as the development microcomputer. The

resulting micro version of EVACNET+ will be able to be run on an IBM

PC or any of it's clones.

129
Reports and Pap ers

1. Thomas M. Kisko and Richard L. Franci s ,"EVACNET+ : A Computer

Program to Determine Optimal Building Evacuation Plans," SFPE

Symposium, Computer Applications in Fire Protection: Analysis,

Modeling, and Design, March, 1984.

130
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution: University of Minnesota, Minneapolis, Minnesota

Grant No .

NB83NADA4057

Grant Title: Method and Apparatus for Quantitative Fit Test of

Respirators

Principal Investigator : Benjamin Y. H. Liu

Professor and Director

Particle Technology Laboratory

Mechanical Engineering Department

University of Minnesota

Minneapolis, MN 55455

Telephone: (612) 373-3043

Other Scientific Personnel : W. Szymanski (Research Associate)

NBS Scientific Officer George Mulholland

Technical Abstract :

The objectives of this research are to investigate the use of

low-cost ionization or light-scattering smoke detectors for quantitative fit-test of respirators, and to develop a quantitative fit-test

apparatus based on the use of such smoke detectors. The apparatus

would include an aerosol generator to produce an aerosol for testing

the face-seal leakage around a respirator and a modified smoke

detector to detect the presence of particles within the face mask of

a respirator. The availability of such a low-cost quantitative fittest apparatus would greatly enhance the effectiveness of respirators.

The research is divided into two parts with Part I focusing on measuring the concentration and size distribution of aerosol particles

produced by various nebulizers and Part II, on determining the sensitivity and response characteristics of smoke detectors to such

particles

The focus of the research so far has been on determining the

output characteristics of various commercially available nebulizers.

To-date a total of seven commercial nebulizers have been tested. The

characteristics of the nebulizers measured include the output flow

rate, droplet generation rate, mass median diameter and the geometrical standard deviation of the output aerosol. The nebulizers were

tested at a series of operating pressures and oleic acid was used

as the test material.

131
The concentration and size distribution of the aerosol was measured with a laser optical particle counter. Model ASAS-300X,

manufactured by PMS, Inc. of Boulder, Colorado. The measured mass median diameter of the droplets ranged from 1.2 to 1.4 and the

geometrical standard deviation, 1.3 to 1.4.

Some preliminary studies were made using the nebulizers along

with a smoke detector as a prototype quantitative fit test apparatus.

The results are encouraging, but further studies are necessary before

definitive results can be reported.

132
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 1984

Institution: Wood Chemistry Laboratory, University of Montana

Grant No . NB81NADA2066

Grant Title : Chemistry of Smoldering Combustion

Principal Investigators : Fred Shafizadeh (deceased)

R. Keith Osterheld and Edward E. Waali

Department of Chemistry

University of Montana

Missoula, Montana 59812

Other Professional Personnel : G. Stuart Petch (Post-doctoral fellow)

William F. DeGroot (Research Assistant)

NBS Scientific Officer : Dr. Thomas J. Ohlemiller

Technical Abstract :

Objective . The objective of this research is to develop a molecular

understanding of the smoldering combustion of cellulose and wood fibers

in order to develop methods for controlling it. In the current studies

we have primarily used cross-polarization magic angle spinning solid

phase 13 C nuclear magnetic resonance spectroscopy (CP/MAS 13 C-NMR) and

combined thermogravimetry and Fourier transform infrared spectroscopy

(TG/FTIR) to describe the chemistry of char structure and reactivity.

Results . The CP/MAS 13 C-NMR spectra of untreated cellulose and chars

prepared from cellulose at various temperatures are shown in Fig. 1.

The 13 C-NMR spectrum of unpyrolyzed cellulose shows distinct peaks for

the resonances corresponding to carbons 1, 4 and 6 and overlapping

peaks for carbons 2, 3, and 5. Heating to 325°C results in a slight

reduction in the intensities of the carbohydrate peaks and the appearance of broad resonances at either side of the carbohydrate region.

At 350°C (67% weight loss) the carbohydrate peaks are significantly

reduced and the spectrum shows resonances at 14 and 34 ppm for methyl

and other paraffinic carbons, 132 ppm for C=C carbons adjacent to C or

H, 154 ppm for C=C adjacent to oxygen, 173 ppm for carboxylic acid and

ester groups, and 211 ppm for aldehydo-and keto-groups. Heating beyond

400°C results in additional weight loss and complete loss of carbohydrate structure. The peak at 132 ppm predominates and becomes sharper

at these temperatures and the paraffinic resonances become more heavily

weighted toward the methyl peak at 14 ppm. It is difficult to distinguish between the aromatic and olefinic carbon by NMR alone, but the

presence of strong resonances for methyl and other paraffinic carbons

indicates that a large fraction of the 3-4 hydrogen atoms present per

6-carbon unit (based on elemental analysis) must be associated with paraffinic structures. This strongly suggests that the remaining carbon

is associated with a fused aromatic system. The permanganate oxidation

studies reported previously, which confirm the presence of highly sub133
Figure 1. CP/MAS ^C-NMR spectra of cellulose chars prepared by heating for 5 min at different temperatures: (a) no treatment; (b) 325°C; (c) 350°C; (d)

400°C; (e) 450°C; (f) 500°C. (The small peaks located in the 240 ppn regions

are spining sidebands.)

stituted aromatic structures in chars prepared at these temperatures,

lend further evidence for a fused aromatic structure of char.

CP/MAS 13 C-NMR of chars prepared from wood and lignin showed substantially the same trends with the exception that the wood and lignin

chars had a more pronounced peak at 148 ppm corresponding to aromatic

carbon bearing methoxyl substituents (<£-0-CH

3

), which arise from the

guaiacyl (4-hydroxy-3-methoxyphenyl propane) subunits of softwood

lignins. The structure of wood char was otherwise found to be nearly

identical with that of cellulose. Similarly, chars prepared from cellulose heated with inorganic additives such as (NH^KHPCL and NaCl were

very similar to those prepared from untreated cellulose, even though

the char yields and temperatures of decomposition varied substantially

between treatments.

134
A major emphasis of this research is to relate chemical structure of

the char to observed reactivity. An important aspect of the reactivity

of cellulosic chars which was previously unexplained was the presence

of two distinct exothermic peaks observed by differential scanning

calorimetry during combustion. The first exotherm occurs at 360°C and

the second at 520°C in untreated cellulose. In order to relate these

two separate stages of reaction to chemical structure, a cellulose char

was heated to 40% weight loss in air and the original and oxidized char

samples were analyzed by CP/MAS 13 C-NMR. The results shown in Figure 2

show that the low temperature oxidation corresponding to the first exo- therm removed only the aliphatic fraction of the char and the aromatic

fraction remains unchanged except for enhanced absorption corresponding

to phenoxy groups (<j)-0-CH3

) due to partial oxidation of aromatic carbon.

The evidence therefore suggests that the two exothermic transitions indicated by DSC are due to two separate combustion processes involving

chemically distinct char fractions.

Figure 2. CP/MAS spectra of the char sample (CPT 4C0°C) before (a)

and after (b) 402 weight loss on oxidation in air (small peaks at about 30 and

225 ppm are spinning sidebands).

135
Combustion catalysts such as sodium chloride catalyzed the combustion

of the aromatic fraction, but did not affect the combustion of the

aliphatic fraction. The results of TG/FTIR studies showed that the

combustion of the aliphatic and aromatic fractions gave similar CO/CCL

ratios, although the ratios varied substantially between treatments.

Publ ications : The following papers have been published or submitted for publication

in the current fiscal year:

1. F. Shafizadeh and Y. Sekiguchi, "Development of Aromaticity in Cellulosic Chars," Carbon , 21 , (1983) 511-516.

2. Y. Sekiguchi, J.S. Frye and F. Shafizadeh, "Structure and Formation

of Cellulosic Chars," J_. Appl . Poly . Sci . Vol . 28, 3513-3525 (1983).

3. F. Shafizadeh and Y. Sekiguchi, "Oxidation of Chars During Smolderinq Combustion of Cellulosic Materials," Combust, and Flame, 55:

171-179 (1984).

4. Y. Sekiguchi and F. Shafizadeh, "The Effect of Inorganic Additives

on the Formation, Composition and Combustion of Char," J. Appl.

Polym . Sci ., 29, 1267-1286 (1984).

5. R.M. Rowell, R.A. Susott, W.F. DeGroot and F. Shafizadeh, "Bonding

Fire Retardants to Wood. Part I. Thermal Behavior of Chemical

Bonding Agents," Wood and Fiber Science , 16, 214-223 (1984).

6. F. Shafizadeh, "The Chemistry of Pyrolysis and Fire Retardants,"

The Chemistry of Solid Wood, R.M. Rowell, ed; Academic Press, New

York, (1984).

136
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Insti tution : University of Notre Dame

Grant No : NBS Grant NB 83 NADA 4018

Grant Title : Scaling Correlations of Flashover Experiments.

Principal Investigator : Professor A. M. Kanury

Department of Aerospace and Mechanical Engr.

University of Notre Dame

Notre Dame, IN 46556

Other Professional Personnel : Mr. M. S. Riepenhoff, Graduate Research

Assistant.

NBS Scientific Officer : Mr. B. T. Lee

Technical Abstract :

The objective of this continuation project is to develop an understanding of the relation and correspondence between the

observations and measurements made on the fire growth process to

flashover in compartments of different scales. Based on this

understanding, experiments on different scales are sought to be

correlated to logically infer (i) whether or not flashover would occur

under a given set of circumstances and (ii) the time to flashover, if it

does occur.

Based on mass and energy conservation laws, the following

functional relation is deduced, in the preceeding grant period (NBS

Grant NB 81 NADA 2021), for the dependency of nondimensional ceiling

surface (j=w) and ceiling-layer gas (j=g) temperatures on nondimensional

time t.

e

j = 0j

^ T * V

Detailed definitions of the parameters (fo, B, ... can be found in Refs.

[1] and [2], Suffice it to point here the significance of these

nondimensional parameters of the room-fire problem. characterizes

the initial fire source (e . g. : a gas burner, a waste-basket fire, an upholstered chair, ...), by being defined as the normalized fuel input

rate. The parameter $ accounts for the ability of the wall -linings,

draperies, etc. which are first exposed to the fire source and which

serve in the initial fire growth; it is defined heuristlcally at present

in terms of the area covered by a gas flame per unit energy input in the

gas flow, heat transfer from the flame to the lining, and measured heat

release rate (per unit exposure irradiance). is the aspect ratio of

the opening to the room. y is a geometric parameter, the ratio of the

137
area of ceiling and upper portions of the walls to the window area. Finally, fl is the ratio of (characteristic) energy retained within the room to heat the surfaces to the energy drained out of the room by the

convective flow through the opening. As such D is a sort of a Stanton

number, the numerator of which is the heat transfer coefficient.

Thermal radiation is taken at present by augmenting this coefficient in

a manner cognizant of the expected radiating smoke-layer thickness.

If the event of flashover is based on any criterion involving the

attainment of a minimum of either the temperature 9j or any direct

function of it (such as the radiant flux to the floor), the preceeding

functional relation gives t* as dependent on the parameters <fo, 3, ip, n and y. Based on this scaling premise. Fig. 1 indicates a correlation of

the NBS mobile home fire tests (42 quarter-scale and 46 full-scale

tests) in which a variety of fire sources, wall and ceiling linings and

room/opening configurations are involved. No systematic variations in

n, y and 4> are prescribed so that this figure can be construed as a preliminary test of the role played by 4^ and 3. When <^,(1+3) is less

than about 2, flashover appears not to be possible. However, when both

the walls and the ceiling are lined with gypsum board, flashover will

not occur even if 4^ and 3 are large. At least a part of the scatter

could be reduced if experiments are available with a systematic

variation in the parameters fl, y and 4>.

In the continuation project, three issues are being studied. These

are: (a) the contribution of the first involved combustibles (viz: the

parameter 3); (b) thermal radiation from the ceiling-layer gas in

augmenting the heat transfer coefficient appearing in the definition of

& and in culminating in a radiant flux to the floor; and (c) the gypsum

board anamoly of Fig. 1. Related to the first of these issues, the role

played by two-dimensional transient heat conduction within the

wall-lining slab has been studied (Ref. [3]) to predict the upward fire

spread on a vertical wall. Simplifying the gas-phase problem to the

prescription of a height-wise variant heat transfer coefficient, and

solving the 2-d transient conduction equation to obtain the temporal

march of the solid surface location where the temperature is equal to a prescribed pyrolysis temperature, the flame height (assumed to be A times the pyrolysis height) history is predicted as shown in Fig. 2.

The most fascinating aspect of this result is that the fire growth

versus time follows an exponential relation.

The implications of this result in room fire scaling are being

examined currently.

Reports and Papers :

[1] Kanury, A.M., "Scaling Correlations of Flashover Experiments," Final

Report Submitted to the National Bureau of Standards, Center for

Fire Research, Grant No. NB 81 NADA 2021, University of Notre Dame,

Notre Dame, IN, 46556, (August 1983).

"Scaling Correlations of Flashover Experiments," Paper

138

[2] Kanury, A.M.,
presented at the ASTM/SFPE Symposium on Application of Fire Science

to Fire Engineering, Denver, CO. To appear in an ASTM Special

Technical Publication edited by T.Z. Harmathy.

[3] Riepenhoff, M.S., "An Investigation of Two-Dimensional Transient

Conduction as Related to Fire Spread on a Vertical Wall," M.S.

Thesis Submitted to Department of Aerospace and Mechanical

Engineering, University of Notre Dame, Notre Dame, IN 46556, (July

1984).

°°l

10

9

8

7

T 6

5

4

3

2

-go —[oo—[O—|

1 r

Rept No a Y * hr /hCo tvn

1530 0.012 15.2 0.34 0.5 wood crib 0

16 kg chair •

1720 II II N II 16 <• A

35 •' 2333 0.017 7.5 0.37 1.0 burner -

16 kg chair X wood crib -

1531 II II II II 16 kg chair V

bed *

2333 0.023 3.9 0.73 0.37 burner o

propone

-L _L

8 10 12 14 &0 + /3)16 18 20 22 24

Figure 1: Correlation of Mobile Home Fire

Tests [1], [2].

139
Zoc&ias

o

i

^

am

a

%

Zoz*a+c£>n

I4.

g

Z~crr>& U -fZtr^cZ ~C

SI,

B' " (V-ri,)° K — Present Prediction

a Data of Fang

Figure 2: 2-d Transient Conduction Predictions

of Upward Fire Spread on a Vertical

Wall [2].

140
CENTER FOR FIRE RESEARCH

NATIONAL BUREAU OF STANDARDS

FY 84

Institution : University of Pittsburgh

Contract Number : 60NANB4D0001

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

Several areas of research are being pursued.

1. Composite Materials

Most of the work conducted on toxicity of plastic decomposition products has been done using single materials such as wood,

polyvinylchloride, polyurethane, etc. We have now completed the

work on six materials. These were non-commercial materials com- monly used in buildings for floor covering, ceiling tiles and

display boards. The work completed indicated that the method used

at the University of Pittsburgh to evaluate toxicity of smoke is

well suited to test composite materials as well as single

materials

2. Visibility

Part of the hazard in a fire is impairment of visibility due

to smoke. This measurement has never been made during thermal

decomposition of materials simultaneously with assessment of the

toxicity. We have developed a nephelometer. This nephelometer is

attached to the animal exposure chamber and permits continuous

monitoring of smoke density during toxicological evaluation.

3. Japanese Samples

Three samples were submitted last October by Japanese investigators for evaluation at the University of Pittsburgh so that

comparisons could be made between our method and theirs. The

samples are polyvinylchloride, polymethylmethacrylate and a fiber

insulation board. Evaluation is about 50% completed.

141
4. New Model for Toxic Hazard Analysis

We have started a new effort in an attempt to obtain data in

a realistic situation of humans escaping smoke from a fire in a corridor. We have developed a "corridor" for mice which consists

of a glass tube of an appropriate diameter so that the mice can run into it only forward or backward and cannot turn around. This

glass tube is 150 feet long and is continuously ventilated with

fresh air. Provisions are made to add contaminants such as CO,

HCN, formaldehyde or smoke so that their effect on the traveling

speed of the animals can be evaluated.

The results obtained so far indicate that the traveling speed

of mice with fresh air ventilation is very reproducible and,

therefore, the study of the effects of toxicants can be

evaluated. Preliminary results with CO indicate that the

traveling speed is reduced in proportion to the CO concentration

and that the total distance covered before complete incapacitation

occurs is also reduced as the CO concentration increases. Thus

two key elements, distance to be covered for escape and time

available to travel this distance, can be used in a hazard

analysis. We can also change the speed at which the toxicant (or

smoke) reaches the animals as they are traveling into the corridor

and take this factor into consideration.

Reports and Papers (This Year)

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. Fund. Appl. Toxicol. _3, 619-621,

1983.

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 COp challenges.

Toxicol. Appl. Pharmracol. 70, 236-238, 1983.

Wong, K.L., Stock, M.F., Malek, D.E. and Alarie, Y. Evaluation of

the pulmonary toxicity of wood smoke in guinea pigs by repeated

COp challenges. Toxicol. Appl. Pharmacol., in press.

Alarie, Y. Toxicity of smoke from polymeric materials during

thermal decomposition. Annual Review of Pharmacology and

Toxicology, in press.

142
APPENDIX A

AGENDA

Annual Conference on Fire Research

National Engineering Laboratory

National Bureau of Standards

October 17, 18, 19, 1984

Wednesday, October 17, 1984

8:15 a.m. Registration, Green Auditorium Lobby

9:00 a.m. Welcome - J. Snell, Director, CFR/NBS

9:10 a.m. Opening Remarks - C. Bragdon, Administrator,

United States Fire Administration

9:15 a.m. J. deRis, 1984 Emmons Lecturer: Flammability

and Radiation

SESSION I: Growth of Fire in a Compartment

9:55 a.m. Session Chairman (Introduction) - P. Pagni,

University of California, Berkeley

10:00 a.m. Internal Flows and Combustion in Two Layer

Room-Fire Models - E. Zukoski, California

Institute of Technology

10:30 a.m. Difficulties in Finding a Correct Solution to

Conservation Equation Used in Multi- Compartment

Transport - W. Jones, CFR/NBS

11:00 a.m. Coffee Break

11:30 a.m. Thermal Response of Unconfined Ceilings Above

Growing Fires and the Importance of Convective

Heat Transfer - L. Cooper, CFR/NBS

12:00 p.m. Effects of Ventilation and Panel Properties

on Temperature Rise from Aircraft Fires -

T. Eklund, FAA

12:30 p.m. Slide-Rule Estimates of Fire Growth -

J. Quintiere, R. Lawson, CFR/NBS

1:00 p.m. Lunch

1U3
SESSION II: Use of Models in Hazard Analysis

2:00 p.m. Session Chairman (Introduction) -

A. Fowell, CFR/NBS

2:05 p.m. CFR Toxic Hazard Assessment: Development and

Application - R. Bukowski, CFR/NBS

2:35 p.m. Use of Mathematical Models in Hazard Assessment -

F. Clarke, I. Benjamin, and P. DiNenno, Benjamin/

Clarke Associates, Inc.

3:05 p.m. Coffee Break

SESSION III: Use, Development, and Validation of Models

3:35 p.m. Session Chairman (Introduction) -

A. Fowell, CFR/NBS

3:40 p.m. Experience with the Harvard Mark VI Program -

H. Mitler, CFR/NBS

4:10 p.m. A Study of Compartment Fires and the Validation

of Computer Models - K. Charter, Owens-Corning

Fiberglas Technical Center

4:40 p.m. Microcomputer Based Stochastic Fire Spread

Analysis - R.B. Williamson, University of

California

5:10 p.m. Adjourn

6:30 p.m. Crab Feast at Cracked Claw

Thursday, October 18, 1984

PARALLEL SESSIONS

a.m. Session IV Alerting, Reactions and Movement of People in

Buildings when Threatened by Fire - Lecture Room B

p.m. Session V Fire Risk Analysis and Fire Risk Data - Lecture

Room B

all day Session VI Data and Subprograms Required for Calculations - Green Auditorium

lhh
SESSION IV: Alerting, Movement and Reactions of People

in Buildings when Threatened by Fire

Lecture Room B

9:00 a.m. Session Chairman (Introduction) -

H. Nelson, CFR/NBS

9:05 a.m. Sound Transmission Loss from Corridors to

Rooms: Implications for Locating Fire Alarm

Sounders - D. Robinson, University of

Massachusetts

9:35 a.m. Response Latencies of the Handicapped and

Elderly to Simulated Residential Fire Egress

Scenarios - R. Pearson, North Carolina State

University

10:05 a.m. Evacuation Technology: An Update on the

Effective Width Model for Crowd Flow Capacity

and Related Changes to Egress Standards -

J. Pauls, National Research Council, Canada

10:35 a.m. Coffee Break

11:05 a.m. Assessment of Escape Routes in Buildings - Discussion of a Design Method for Calculating

Pedestrian Movement - E. Kendik, Institut fur

Hochbau fur Architekten, Austria

11:35 a.m. Modeling Emergency Evacuation - D. Alvord,

American Institute of Architects Foundation

12:05 p.m. Transit Station Evacuation Evaluation -

G. Berlin, Modeling Systems, Inc.; and

W. Hathaway, DoT, Transportation Systems

Center

12:35 p.m. Early Actions in Fire Emergencies - B.M. Levin,

CFR/NBS; and J. Keating, University of Washington

1:05 p.m. Lunch

1^5
SESSION V: Fire Risk Analysis and Fire Experience Data

Lecture Room B

2:00 p.m. Session Chairman (Introduction) - J. Hall,

National Fire Protection Association

2:05 p.m. Ignition Risk Analysis - Cigarette Ignition

of Upholstered Furniture - K-N Yeh, University

of Maryland

2:35 p.m. Fire Protection of Flammable Work Stations in

the Clean Room Environment of a Microelectric

Fabrication Facility - D. Crinnion, F. Fisher,

G. Toms, R.B. Williamson, University of

California at Berkeley

3:05 p.m. Coffee Break

3:35 p.m. Relationships Between Worker Casualties, Other

Fire Loss Indicators, and Fire Protection

Strategies - J. Moran, Department of Health and

Human Services

4:05 p.m. Suppression and Extinguishment of Fire - 98

Years of Experience with Automatic Sprinkler

Systems in Australia - H. Marryatt, Australia

4:35 p.m. Development of a Fire Safety Code for Buildings

for Saudi Arabia - K. Basham, Saudi Arabian

Standards Organization

5:05 p.m. International Concepts in Fire Protection:

Japan and Hong Kong - P. Schaenman, TriData

Corporation

5:35 p.m. Adjourn

9:00 a.m.

SESSION VI: Data and Subprograms Required for Calculations

Green Auditorium

Session Chairman (Introduction) - J. deRis,

Factory Mutual Research Corporation

9:05 a.m. Heat Release Rate of Wood - W. Parker, CFR/NBS

9:35 a.m. The Behavior of Furniture Frames During Fire -

G. Springer, Stanford University

lk6
Thursday, October 18, 1984 - Session VI Continued

10:05 a.m. A Simplified Characterization for Upholstered

Furniture Heat Release Rates - V. Babrauskas,

CFR/NBS

10:35 a.m. Coffee Break

11:05 a.m. Flammability Testing of Thermoplastic Films for

Aircraft Interior Applications - D. Kour tides.

National Aeronautics and Space Administration

11:35 a.m. Heat Release from Wall Assemblies Containing

Fire Retardant Treated Wood - J. Brenden,

Forest Products Laboratory

12:05 p.m. Combustion Chemistry in Fires - A. Tewarson,

Factory Mutual Research Corporation

12:35 p.m. Simulation of Negatively Buoyant Flows Arising

in Enclosure Fires - D. Boldman, Y. Jaluria,

Rutgers University

1:05 p.m. Lunch

2:00 p.m. Practical Thermal Radiation Model for 3-D Gray

Flames and Objects - M. Dietenberger

,

University of Dayton

2:35 p.m. Use of Computer Fire Models in Corner Burn

Tests - E. Dickens, Jr., G. Smith, B.F. Goodrich

3:05 p.m. Coffee Break, Employees Lounge

3:35 p.m. Smoke Control in Hospitals/Bedroom Buildings - 0. Meland, River and Harbour Laboratory, SINTFF,

and E. Skaret, Norwegian Institute of Technology

4:05 p.m. The Acute Toxicological Effects from the

Inhalation of Single and Multiple Fire Gases -

B. Levin, CFR/NBS

4:35 p.m. How to Report the Results from the University

of Pittsburgh Toxicity Test - Y. Alarie,

University of Pittsburgh

5:05 p.m. Adjourn

6:30 p.m. International Reception at the Quality Inn
Friday, October 19, 1984

SESSION VII: Fire Suppression and Detection

9:00 a.m. Session Chairman (Introduction) -

G. Heskested, Factory Mutual Research

Corporation

9:05 a.m. Direction for Improving Manual Fire Suppression

Using Physically Based Computer Simulations -

L. Pietrzak, G. Johanson, Mission Research

Corporation

9:35 a.m. Water Spray Suppression of Gas-Well Blowout

Fires - D. Evans, B. McCaffrey, CFR/NBS

10:05 a.m. Modes of Fire Suppression - R. Sheinson,

J. Hahn, D. Indr it z, National Research

Laboratory

10:35 a.m. Coffee Break

11:05 a.m. Effectiveness of Fire Control Agents on Hexane

Fires - J. Welker, University of Arkansas

11:35 a.m. Metal Fire Extinguishment - T. Sharma, B. Lai,

J. Singh, Central Building Research Institute,

Roorkee, India

12:05 p.m. Comparative Effectiveness of Solid, Liquid and

Gaseous Inhibitors in Adiabatic and NonAdiabatic Premixed Flames - H. Kim, P. Taylor,

J. Reuther, Pennsylvania State University

12:35 p.m. Principles for Fire Detection - J. Newman,

Factory Mutual Research Corporation

1:05 p.m. Experimental and Analytical Study of Fire

Sprinkler Scaling Laws - J. Prahl, Case

Western Reserve University

1:35 p.m. Closing Remarks

1:45 p.m. Adjourn
APPENDIX B

1984 CONFERENCE ON FIRE RESEARCH

October 17, 18, 19

LIST OF PARTICIPANTS

ADAMS, Pat, Man Made Fiber Producers Association, 1150 17th Street, N.W. , Washington, D.C. 20036

ALAHDADI, Firooz, University of New Mexico Civil Engineering Institute,

Campus P.0. Box 25

ALARIE, Yves, Graduate School of Public Health, University of Pittsburgh,

130 DeSoto Street, Pittsburgh, Pennsylvania 15261

ALMAND, Charles W. , U.S. Gypsum Co., 1050 17th Street, Suite 1150,

Washington, D.C. 20036

ALVARES, Norman, Lawrence Livermore National Laboratory, P.0. Box 808,

L442, Livermore, California 94550

ALV0RD, Danial, American Institute of Architects Foundation, 1735 New York

Avenue, N.W., Washington, D.C. 20006

AMED, Earle B. , Bureau of Mines, 2401 E. Street, N.W., Washington, D.C.

ANSON, Bruce D., Rohm and Haas Company, P.0. Box 219, Bristol,

Pennsylvania 19007

BAS' HAM, Khaled S., Construction and Building Materials Section - SAS0,

P.0. Box 3437, Riyadh 11471, Saudi Arabia

BEAN, J. Michael, Lord Bis sell, and Brook, 115 South LaSalle Street,

Chicago, Illinois 60603

BEITEL, Jesse J. , Southwest Research Institute, 6220 Culebra Road,

San Antonio, Texas 78216

BERLIN, Geoffrey, Modeling Systems, Ine-* , Boston, Massachusetts

BLAIR, John A., E.I. du Pont de Nemours & Co., Polymer Products Dept.,

Chestnut Run, Building 713, Wilmington, DE 19898

BORING, Delbert F. , American Iron & Steel Institute, 4937 West Broad Streo*.,

Columbus, Ohio 43228

BOVERMAN, David Asher, EG&G, Florida, P.0. Box 21267, Kennedy Space Cei.v -

,

Florida 32815

BRAGD0N, Clyde, United States Fire Administration, 16825 S. Seton

Emmitsburg, Maryland 21727

BRENDEN, John J., USDA, Forest Service, Forest Products Laborn*. r.-, Pinchot Drive, Madison, Wisconsin
BRYAN, John L. , University of Maryland, Department of Fire Protection

Engineering, College Park, Maryland 207^+2

BUCHANAN, Michael, W.T. Burnett Company, 1500 Bush St., Baltimore,

Maryland 21230

CHARTER, Ken, Owens Corning Fiberglas Corporation, Technical Center,

Granville, Ohio i+3023

CHIDESTER, Joyce, Foundation for Fire Safety, 1700 North Moore Street,

Rosslyn, Virginia 22209

CUSTER, Richard, Worcester Polytechnic Institute, Center for Fire Safety

Studies, Worcester Polytechnic Institute, . Worcester , Massachusetts

01609

DALY, Thomas, Hilton Hotels Corporation, 9880 Wilshire Boulevard,

Beverly Hills, California 90210

DAVIS, Sanford, Center for Fire Research, National Bureau of Standards,

Gaithersburg, Maryland 20899

DENNIS, Cornelius F. , Department of Buildings, City of New York, 120 Wall

Street, New York, N.Y. 10005

DeRIS, John, Factory Mutual Research, Norwood, Massachusetts 02062

DICKENS, E. Douglas Jr., B. F. Goodrich R&D Center, 9921 Brecksville

Road, Brecksville, Ohio i+UlUl

DIETENBERGER, Mark A. , Univeresity of Dayton Research Institute, 300 College

Park, Dayton, OH U 5^+69

DiNENNO, Philip J. , Benjamin/Clarke Associates, Inc., 10605 Concord Street,

Suite #501, Kensington, Maryland 20895

DUNLAP, W.A., Dow Chemical USA, P.0. Box 515) Granville, Ohio U3023

ECHTERNACHT, John E. , Wormald U.S., Inc. , 180 Grand Avenue, Suite 900,

Oakland, California 9^-612

EKLUND, Thor, FAA Technical Center, ACT 350, Building 20U, Tilton Road,

Atlantic City, New Jersey 08405

ENGLER, Nicholas A., University of Dayton Research Institute, 300 College

Park, Dayton, Ohio b^k69

FAETH, G.M. , Pennsylvania State University, 315 M.E. Building, University

Park, Pennsylvania 16802

FESMAN, Gerald, Stauffer Chemical Company, Grasslands Road, Elms ford,

NY 10523

FOOTE, Kenneth L. , Lawrence Livermore National Laboratory, P.0. Box 808, L-hk2

,

Livermore, California 9^+550

150
FOWELL, Andrew, Center for Fire Research, National Bureau of Standards,

Gaithersburg, Maryland 20899

FRIEDMAN, R., Factory Mutual Research, Norwood, Massachusetts 02060

GANDHI, Pravinray, Unverwriters Laboratories, Inc., 333 Pfingsten Road,

Northbrook, Illinois 60062

GARN, Paul D. , Center for Fire and Hazardous Materials Research

University of Akron, Akron, Ohio kb325

GEWAIN, Richard G., American Iron and Steel Institute, 1000 l6th Street,

N.W., Washington, D.C. 20036

GL0WINSKI, Robert W. , National Forest Products Association, 1619

Massachusetts Avenue, N.W., Washington, D.C. 20036

GOREN, Simon L., Department of Chemical Engineering, University of

California, Berkeley, California 9^+720

GREENAUGH, Kevin C., NRC , Washington, D.C. 20555

HALL, John, National Fire Protection Association, Batterymarch Park,

Quincy, Massachusetts 02269

HARRIS, Carl, Department of Systems Engineering, University of Virginia,

Charlottesville, Virginia 22901

HARTZELL, Gordon E., Southwest Research Institute, 6220 Culebra Road,

San Antonio, Texas 7828U

HASEGAWA, Harry K. , Lawrence Livermore National Laboratory, P.0. Box 55501,

L-^2, Livermore, California 9^-550

HATHAWAY, C. E. , Monsanto Company, 800 North Lindbergh

HAWKINS, W. Frank, Watts Bar Nuclear Plant, P.0. Box 800, Spring City,

Tennessee 37381

HEIMANN, David, DTS6-65 , U.S. DoT, Transportation System Center,

55 Broadway, Cambridge, Massachusetts 021^2

HESKESTAD, Gunnar, Factory Mutual Research Corporation, 1151 Boston- Providence

Highway, Norwood, Massachusetts 02062

HIRSCHLER, F.F. Goodrich Chemical Group, Avan Lake Technical Center, Avon

Lake, Ohio ^U012

151
HOLMES, Wayne D., American Nuclear Insurers, 270 Farmington Avenue,

Farmington, Connecticut 06032

HOPPER, Richard Ned, Carpet and Rug Institute, Suite 1000, 1100 17th Street,

N.W. , Washington, D.C. 20036

HUGGETT, Clayton, Center for Fire Research, National Bureau of Standards,

Gaithersburg, Maryland 20899

INDRITZ, Doren, Exxon Research and Engineering Company

JALURIA, Yogesh, Mechanical Engineering Department , Rutgers University,

New Brunswick, New Jersey 08903

JONES, Walter, Center for Fire Research, National Bureau of Standards,

Gaithersburg, Maryland 20899

J0NSS0N, Robert, Division of Building Fire Safety and Technology, Lund

Institute of Technology, P.0. Box 118, S-221 00, Lund, Sweden

KAMINSKI, Andrzej, DTS 6-6 5, U.S. DoT, Transportation System Center,

55 Broadway, Cambridge, Massachusetts 02lb2

KELLEY, Ronald, Dow Corning Corporation

KENDIK, Ezel, Argentiniestr 28/10, 10^0 Vienna, Austria

KISK0, Tom, University of Florida, 303 Weil Hall, Gainesville,

Florida 32611

K0FFEL, William E. Jr., Gage-Babcock & Associates, Inc., 301 Maple Avenue,

West, Suite 2-F, Vienna, Virginia 22180

K0URTIDES, Demetrius A. , National Aeronautics and Space Administration,

Ames Research Center, N223-6, Moffett Field, California 9^035

KUBU, Edward T., Allied Corporation, Fibers Division, P.0. Box 31,

Petersburg, Virginia 23804

LABES, Willis G., Prof. Emeritus, IIT, 1000 Allendale Drive, Charlottseville

,

Virginia 22901

LANGE, Bob, Mobil Research and Development

LAWSON, Randy, Center for Fire Research, National Bureau of Standards

Gaithersburg, Maryland 20899

LEVINE, Robert S., Center for Fire Research, National Bureau of Standards,

Gaithersburg, Maryland 20899

LEVY, Arthur, Battelle, Columbus Laboratories, 505 King Avenue, Columbus

Ohio U3201

152
LUND, Peter D., Society of Fire Protection Engineers, 60 Batterymarch

Street, Boston, Massachusetts 02110

MALHOTRA, H.L. , Consultant, 44, Goodyers Avenue, Radclift Hurts, U.K.

MITLER, Henri, Center for Fire Research, National Bureau of Standards,

Gaithersburg, Maryland 20899

MODY, Mahesh J., City of New York, Department of Buildings, 120 Wall Street,

New York, New York 10005

M0REHART, Jonas L. , National Institutes of Health, Rm. C102, Building 31,

9000 Rockville Pike Bethesda, Maryland 20205

MULHAUPT, Rick, NFPA Research Foundation, Batterymarch Park, Quincy,

Massachusetts 02269

NEWMAN, Jeffrey S. , Factory Mutual Research Corporation, 1151 Providence

Highway, Norwood, Massachusetts 02062

NORTHCOTT, Julian, Kling Lindquist, Inc., 2301 Chestnut Street,

Philadelphia, Pennsylvania

PACKHAM, Steven, 996 South 1500 East, Salt Lake City, Utah 84105

PADDEN, Noes B. , United States Fire Administration, 16825 S. Seton Avenue,

Emmitsburg, Maryland 21727

PAULS, Jake, National Research Council Canada, Rm. 178, Building M-50,

NRC Canada, Ottawa, Canada KIA0R8

PEARSON, Richard, North Carolina State University, School of Engineering

Department of Industrial Engineering, Box 5511 , Raleigh, North

Carolina 27650

PEDL0W, J. Watson, Quelcor Division, Thomas and Betts Corporation,

P.0. Box 33, Medio, Pennsylvania 19863

PIETRZAK, Larry, Mission Research Corporation, P.0. Drawer 719 » Santa

Barbara, California 93102

PLATTS, Francis H. , Westinghouse Electric Corporation, P.0. Box 248,

Hampton, South Carolina 29924

PRAHL, Joseph M. , Department of Mechnical and Aerospace Engineering,

Case Western Reserve University, Cleveland, Ohio 44106

PRZYBYLA, Underwriters Laboratories Inc. , 333 Pfingsten Road, Northbrook,

Illinois 60062

153
REMMERS, Gene M. , David Taylar Naval Ship R&D Center, Code 1202, Bethesda,

Maryland 20004

REUTHER, James J. , Battelle Columbus Laboratories, 505 King Avenue,

Columbus, Ohio 43201

ROBINSON, Donald, Environmental Health and Safety, University of

Massachusetts, N4l4 Morrill Science Center, Amherst, Massachusetts 01003

ROUX, H.J., Armstrong World Industries, Inc., Lancaster, Pennsylvania 17604

SCHAENMAN, Philip, TRIData Corporation, 1500 Wilson Boulevard, Arlington,

Virginia 22209

SHAW, W.A., Hoechst Fibers Industries, P.0. Box 5887 » Spartanburg, South

Carolina 29304

SHOUMAN, Ahmad, University of New Mexico Engineering Institute, Campus

P.0. Box 25

SKAARET, Eimund, Norwegian Institute of Technicology , Division of Heating

and Ventilating, N-7034 Trondheim - NTH, NORWAY

SMITH, Gregory F. , B.F. Goodrich Technical Center, P.0. Box 122, Avon Lake

.Ohio 44012

SNELL, Jack E. , Center for Fire Research, National Bureau of Standards,

Gaithersburg, Maryland 20099

SPRINGER, George S., Stanford, University, Department of Aero/Astro, Stanford,

Connecticut 94305

STIEFEL, Wayne, Center for Fire Research, National Bureau of Standards,

Gaithersburg, Maryland 20099

SULTAN, M.A., National Research Council of Canada, Ottawa, Ontario K1A 0R6

(Building M-59)

TEWARS0N, A., Factory Mutual Research Corporation, 1151 Boston-Providence

Turnpike, Norwood, Massachusetts 02062

T'lEN, James S., Case Western Reserve University, Department of Mechanical

and Aerospace Engineering, Cleveland, Ohio 44106

THOMAS, Emory, Brunswick Defense, 3333 Harbor Blvd, , Costa Mesa,

California 92626

TUCKER, Richard B.C. Jr., STX, Inc., 8989 Yellowbrick Road, Baltimore

Maryland

154
WATTS, Jack, Fire Safety Institute, P.O. Box 67^5 Middlebury, Vermont

05753

WECKMAN, Beth, Department of Mechanical Engineering, University of

Waterloo, Waterloo, Ontario, Canada N2L 3G1

WEINTRAUB, Arnold A., U.S. Department of Energy, 5112 Russett Road,

Rockville, Maryland 20853

WELKER, J. Reed, University of Arkansas, 227 Engineering Building,

Fyetteville, Arkansas 72701

WENDT, Bruce, Department of Mechanical and Aerospace Engineering, Case

Western Reserve University, Cleveland, Ohio Ul+106

WHITE, James A. Jr., Weyerhaeuser Company, P.O. Box 188, Longview,

WA 98632

WILLIAMSON, R. Brady,- Department of Civil Engineering, University of

California, Berkeley, California 9^720

WINGER, James, Center for Fire Research, National Bureau of Standards,

Gaithersburg, Maryland 20899

YEH, K. , University of Maryland, 2100 Marie Mount, College, Park,

Maryland 207^2

YING, Shuh-Jing, University of South Florida, Fowler, Avenue, Tampa,

Florida 33620

YOU, Hong-Zeng, Factory Mutual Research Corporation, 1151 Boston-Providence

Turnpike, Norwood, Massachusetts 02062

ZUKOSKI, Edward E. , California Institute of Technology, Pasadena,

California 91125

155
NBS-114A (REV. 2 -80) U.s. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

PUBLICATION OR

REPORT NO.

NRSIR 85-3136

2. Performing Organ. Report No, 3. Publication Date

April 1985

4.

TITLE AND SUBTITLE

5.SUMMARIES OF CENTER FOR FIRE RESEARCH GRANTS AND IN-HOUSE PROGRAMS - 1984

AUTHOR(S)

Sonya M. Cherry

6

.

PERFORMING ORGANIZATION (If joint or other than NBS, see instructions) 7 . Contract/Grant No. NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE S. Type of Report & Period Covered

WASHINGTON, D.C. 20234

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP)

10.

SUPPLEMENTARY NOTES

J Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11.

ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bi bl iography or literature survey, mention it here)

This report was prepared for distribution at the 1984 Annual Conference

on Fire Research, October 17-19, 1984. It 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.

12.

KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key wo rds by semicolons)

Evacuation; combustion; extinction; fire models; flame spread; ignition;

polymers; smoke; soot; toxicity.

13. AVAILABILITY 14. NO. OF

PRINTED PAGES

QX] Unlimited

| | For Official Distribution. Do Not Release to NTIS

.

1 Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 161

15. Price 20402.

Order From National Technical Information Service (NTIS), Springfield, VA. 22161 $16.00

U S COMM- DC 6043-P80