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Pub,i * Reference * ' II

NBSIR 82-2537

An Assessment of Correlations

Between Laboratory and

Full-Scale Experiments for the

FAA Aircraft Fire Safety Program,

Part 5: Some Analyses of the

Post Crash

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Washington, DC 20234

and

Building Research Institute

Japan

July 1982

i

Sponsored by: " c Department of Transportation

al Aviation Administration

lical Center

tic City Airport, NJ 08405

NBSIR 82-2537

AN ASSESSMENT OF CORRELATIONS

BETWEEN LABORATORY AND

FULL-SCALE EXPERIMENTS FOR THE

FAA AIRCRAFT FIRE SAFETY PROGRAM,

PART 5: SOME ANALYSES OF THE

POST CRASH

AUG 1 9 1992

G?C_ | oO

i <J> S“L=> |9S9

James G. Quintiere

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Washington, DC 20234

and

Takeyoshi Tanaka (Guest Worker)

Building Research Institute

Japan

July 1982

Sponsored by:

U.S. Department of Transportation

Federal Aviation Administration

Technical Center

Atlantic City Airport, NJ 08405

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

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
;.?cl

C i OL! A ' • • :
ABSTRACT

An attempt is made Lo develop mathematical predictions for various aspects

of the dynamics of post crash aircraft fires. The basis of the analysis

is the experimental simulation scenario under study by the FAA. The effects

of wind are considered as well as the effect of interior and exterior fires.

Suggestions are presented for estimating cabin door flow rates from measured

temperatures.

Keywords: Doorway flows, mathematical modeling, post crash aircraft fires,

wind effects
. f.
TABLE OF CONTENTS

Page

INTRODUCTION 1

Purpose 1

Background 1

ANALYSIS OF WIND EFFECTS 1

SIMULATION OF A POST CRASH FIRE SCENARIO 2

FLOW MEASUREMENTS 4

REFERENCES 6

APPENDIX
LIST OF ILLUSTRATIONS

Figure Page

Aircraft Cabin Schematic 8

Cabin Temperature Due to Wind and External Fire 9

Prediction of Cabin Temperature for an External Fire Under

Wind Conditions 10

Predicted Cabin Temperature Due to External Pool Fire and

Cabin Fire (No Wind) 11

2 Predicted Cabin Fire Induced Flows for 4.5 m Pool Fire 12

2 Predicted Cabin Temperature and Smoke Layer Height for 6.0m

Pool Fire and Various Cabin Fires 13

2 Predicted Cabin Fire Induced Flows for a 6 m Pool Fire 14

A-l Conditions at an Opening A-l
LIST OF TABLES

Table Page

1 Cabin Temperature Dependence on Pool Fire and Cabin Fire 7

A-l Limits of Integration A-2

A-2 Rate of Air Flow Estimated from Temperature Data A-3

iii
NOMENCLATURE

A

c P C

g

H

H

o m

m

P

P

Q

Q

P

r

R

T

Vw

z

AH

K

door area

specific heat

flow coefficient

gravitational acceleration

heat loss coefficient (Eq. (3))

door height

mass

mass rate of fuel specified for internal fire

pressure

energy release rate

energy release rate corresponding to m

P

stoichiometric air to fuel ratio

fire plume radius

temperature

wind velocity normal to door

vertical coordinate

heat of reaction

P

a

Subscripts

i

f

0

P

d

u

1

density

radius factor (Eq. (8))

inflow or inside

fuel

ambient or outside

fuel for internal fire

pertains to fuel at an opening

upper layer

lower layer

reference -state

iv
ACKNOWLEDGEMENT

This study was sponsored by the Fire Safety Branch of The Federal Aviation

Administration Technical Center at Atlantic City, New Jersey. The author

gratefully appreciates the advice of Mr. R. Hill, the technical monitor,

and also the assistance of Mr. C. Sarkos of the FAA.

INTRODUCTION

PURPOSE

The development of correlations between laboratory test methods and fullscale fire behavior does not only depend on the appropriateness of the laboratory

test. The dynamics of the full-scale fire scenario must also be understood, at

least in qualitative terms. Part of this insight must come from actual fire

simulation experiments. In addition, it is necessary to analyze those data and

develop mathematical modeling of at least aspects of the scenario to produce

generalized results. Some results of data analysis and modeling will be

presented for the wide-body post crash aircraft fire currently under study by the

FAA.

BACKGROUND

Full-scale fire studies have been conducted by Brown [1] using a DC7 fuselage and Hill, Johnson and Sarkos [2] using a C133 fuselage. These studies

addressed the post crash fire scenario by considering a large external fuel

pool fire adjacent to an open cabin door. Various temperature, heat and

gas data were collected, and the effect of external ambient wind conditions,

pool size and door openings were examined. Eklund and Wright [3] did a small

scale study to examine the effect of door location relative to the pool fire.

Stuart [4] presented an analysis based on Bernoulli’s equation, for computing

the air flow rate through cabin door openings due to wind effects. More

recently Emmons [5] presented a more complete mathematical analysis of the

ingestion of fire gases into the cabin door opening. He proposed methods to

include the entrainment effect of the external fire, the capture of pool fire

gases due to plume expansion, and the flow due to pressure differences inherent

in the wind flow. The "capture" phenomenon is very complex and, in fact, manifests

itself as a pulsation of flames at the cabin door [6]. Modeling this effect may

require further attention. Nevertheless an understanding of the processes can be

developed through these mathematical modeling concepts, and these concepts have

been used in the analyses which follow.

ANALYSIS OF WIND EFFECTS

The experimental study by Hill et al. [2] will be used as a source of data

and a basis for analysis. A schematic of that experiment is shown in Figure 1

in a somewhat distorted form. For ease in illustration the doors are shown on

the ends, the cabin is considered rectangular in cross-section, and the wind is

directed normal to the fire door while the exit door experiences ambient pressure

since it was baffled from the wind. The objective will be to construct some appropriate models and perform some sample computations to illustrate the dynamics

of the transport of heat and mass in the aircraft as a function of wind conditions,

and external and internal fire sizes for this port crash scenario.

The first approach taken was to attempt a correlation for the cabin temperature

data (at time t = 240s) given in Figure 16-18 of reference [2]. These data represent

the cabin upper gas temperature due to various wind conditions and various external

pool fire dimensions. Since the external fuel fire has large flame dimensions

relative to the doorway, it was assumed that the rate of energy release in the

cabin is controlled by the rate of air flow into the cabin through the fire door.

This flow is actually composed of fuel, air and products and is considered to be

fuel rich such that sufficient fuel is available to cause all the air to react.

1
Thus, the rate of air flow in through the cabin doorway controls the rate of

energy release. For simplicity this flow is taken as a stoichiometric mixture

with r as the air fuel ratio. Hence the inflow rate

it^ = m

f (1 + r) (1)

where m

f is the fuel burning rate of the gases entering the cabin due to wind

effects. This flow is driven through the cabin door primarily by the stagnation pressure resulting from the normal wind velocity (V ). From Bernoulli’s

equation and orifice flow theory (neglecting the effect of the exit opening)

m. = Cp V A

1 o w

where C is a flow coefficient,

p is the ambient density,

o and A is the opening area of the door.

( 2 )

An energy balance was performed for a control volume between the fire door

and the temperature data station (Figure 1) . The wind conditions were assumed

to dominate so that only unidirectional flow occurred (fire to exit door) .

m. c (T-T ) = mc AH - H(T-T ) (3) l p o f o The enthalpy flow rate equals the energy release in the cabin minus the heat

loss where

AH is the heat of combustion of the pool fire fuel,

H is an effective wall heat loss coefficient,

T is the average temperature in the cabin,

T is ambient (initial) temperature,

and c is the specific heat.

P Combining Eqns ( 1) — (3) yields

AH

T-T =

c p(i+r) (l + —£

)

_1

\ c Cp AV / \ p o w /

(A)

If H is large, implying a large surface heat transfer area (not unreasonable

in the C133 experiments) , then T-T should be directly proportional to V . The data were examined on that basis and a plot of the results was shown in

Figure 2. It should be noted that the temperature station is 3 m from the door

and 1.7 m from the floor, and the time-averaged wind velocity normal to the

door is based on measurements taken by cup and vane type sensors located at

the front and rear of the fuselage. Except for perhaps two data points (one in

which the thermocouple was probably in the flames and therefore not representative

of an average gas temperature) , the results are encouraging. They suggest that

Eq. (4) could serve as a guide in estimating the effect of the external fire and

wind on the cabin temperature rise.

SIMULATION OF A POST CRASH FIRE SCENARIO

Since this approach of correlating the wind effects on cabin temperature was relatively successful it encouraged further analysis. Tanaka's existing model

[6], considers mass, energy and specie conservation for a homogeneous combustion

product zone (upper layer) and an air zone (lower layer). Various vertical

openings can be considered in the computation and a fire source plume is

specified in one compartment. The current application considers a single room

cabin with two door openings. In addition the post crash fire analysis was addressed by introducing the following modifications:

2
(1) Flow Into the cabin at the fire door was assumed to react in

stoichiometric proportion (i.e. burning is air controlled) such

that the rate of energy added to the cabin from the pool fire

due to pressure differences is

Q

m

1 AH

i = (r+1)

* (5)

The flow rate nu and the energy release rate Q

i

enter the hot layer

of the cabin compartment in Tanaka’s model [6].

(2) Flow at each door is governed by the existing pressure differences.

The fire door is affected by pool fire entrainment and wind if

present. The entrainment effect is negative causing flow out. The

exit door has normal ambient pressure (p^) imposed outside the

cabin. The external pressure imposed at the fire door is given by

superposition of wind and pool fire effects:

, 1 „2 1 / dm \

2 p = p +rp V tt- ( -J- 1 ^

(6) " 2 °“

8„

2

p R

2

\

dz /

O

R is the plume radius, z is the height and m is the plume flow

rate. The last term in Eq. (6) results from an application of

Bernoulli's equation to a streamline starting from rest and extending

to the fire plume. McCaffrey's [7] entrainment model was used

where rate of entrainment.

(3)

m = 6 */ 0 - 053^’ 5 < °' 2

P 1 0.063C 7

, K > 0.2

•2/5 where £ = z/Q^ and m (kg/s), Q (kW), z(m).

For the external pool fire it follows that £ < 0.2 and

dm *0.48 0.3

-r— = 0. 137 Q z dz x p

•2/5

and R = aln m, m=10., a=0.128z + 0.0062Q with (kcal/s)

Two cases were computed.

(7)

( 8 )

Case a . Wind is considered and a net heat addition due to the

"capture" or pulsating flame phenomenon is specified as a fixed

rate of fuel (mp) available at the fire door. A stoichiometric

amount of air is also added. A 4 x 6 ft (2.16 m^) pool fire was used.

Case b . An internal cabin fire is specified (m ) which would simulate

the ignition of cabin furnishings. The effect Bf fire location is

not accounted for by this model. No wind or flame pulsation effects

were considered, although they could in principle be included. Both

6 x 8 ft (4.5 m^) and 8 x 8 ft (5.0 m^) pool fires were used. The

following property values and data were used for the cabin geometry

in Figure 1.

3
Kerosene fuel : r = 15, 30

AH = 42 kJ/g

burning rate = 0.064 kg/m -s

Cabin interior : conductivity = 1.2 x 10 ^ kW/m-K

specific heat = 1.0^ kJ/kg-K

density = 500. kg/m

thickness = 10 cm emissivity = 0.8

Although these data may not match the full-scale conditions perfectly,

the fuel estimates are felt to be reasonable and the wall data should

not have a strong influence on the flow results.

The results for Case a are shown in Figure 3. They are in qualitative

agreement with the data of Hill et al. [2], and could be adjusted into

quantitative agreement by selecting "best values" for the parameters r and

A . Uncertainties in r relate to lack of a mixing rate model for fuel and

aSr, and in m due to lack of a quantitative understanding of flame pulsation

in the doorwa^. This analysis, however, does provide a framework for more accurate

modeling

.

The results for Case b are displayed in Figures 4-7. Two external pool

fires are considered 6 x 8 ft (4.5 m^) and 8 x 8 ft (6.0 m^) and the internal

fire is varied from 10 to 70 g/s with AH = 42 kJ/g. Both fires are considered

to begin impulsively at the same time. A competition exists between the internal

and external fires for "air" flow through the fire door. For a small internal

fire, flow is completely from the cabin at the fire door as the computed results

show. The curves labeled "air" and "smoke" in Figures 4 and 6 are the rates of

flow from (or to) the cold cabin air layer and from the hot upper cabin layer,

respectively. The term "air" is used loosely since it could pertain to pool

fire gases. When "air" flows txj the cabin through the fire door it reacts

in this model. In the modified Tanaka model this flow and release cf heat is

absorbed into hot cabin upper layer. The conditions which cause these pool

fire gases to enter the cabin are shown to depend on internal fire size and

time. In fact the entering of a substantial flow of pool fire gases into the

cabin is a critical event. Table 1 summarizes the results of this critical

flow reversal event. For a 4.5 m^ external pool fire, flames will enter the

cabin for an internal cabin fire of 2520 kW at 70 s. For the larger pool fire

(6.0 m^), this occurs for a 2940 kW cabin fire at 90s. These cabin fire sizes

may represent at least fire involvement of several seats, but obviously the

development of the fire spread on the seats is not accounted for in these

calculations. Nevertheless these results provide insight on the dynamics of

the post crash fire and a framework for developing correlations based on cabin

material performance.

FLOW MEASUREMENTS

It would be useful to establish the credibility of these calculations through

comparison with experimental results. An essential experimental component would

be the determination of the doorway flow rates. This would be very difficult

to achieve at the fire door because of flow disturbances due to the pool fire,

but much more easily done at the exit door. A basis for determining this flow

rate has been established by Steckler et al. [8] and utilizes temperature

measurements alone. A discussion of this approach is presented in the Appendix.

4
It should be possible to utilize this technique in the FAA post crash fire

experimental facility. The establishment of confidence in this model would

lead to the prospect of considering a more realistic fire spread scenario.

Such an analysis would be desirable in developing correlations between performance of materials in the post crash experiments and test method data. It

is clear, however, from these calculations and observations of the full-scale

tests that only some fraction of the energy, smoke, and combustion products

from the interior cabin fire is flowing out of the cabin at the fire door.

Also when the internal fire becomes large enough, more significant quantities

of the pool fire gases are drawn into the cabin. Any correlation strategy,

assessment of human tolerance levels in the cabin or egress potential at the

exit door needs to account for these fire dynamic characteristics.

5
REFERENCES

1. Brown, L. J. (Jr), "Cabin Hazards from a Large External Fuel Fire

Adjacent to an Aircraft Fuselage", Federal Aviation Administration

Report No. FAA-RD-79-65, (August 1979).

2. Hill, R. G. , Johnson, G. R. , and Sarkos, C. P., "Postcrash Fuel Fire

Hazard Measurements in a Wide-Body Aircraft Cabin", Federal Aviation

Administration Report No. FAA-NA-79-42 , (Dec. 1979).

3. Eklund, T. I., and Wright, J. A., "Fuel Fire Hazard Penetration into a Model Fuselage as a Function of Circumferential Door Location and Fuel

Bed Height", Federal Aviation Administration Report No. FAA-NA-80-9,

(May 1980).

4. Stuart, J. W. , "Fuselage Ventilation Due to Wind Flow About a Postcrash

Aircraft", Jet Propulsion Laboratory Publication 80-36, (June 1980).

5. Emmons, H. W. , "The Ingestion of Flames and Fire Gases into a Hole in an Aircraft Cabin for Small Tilt Angles and Low Wind Speeds", Harvard University,

Home Fire Project Technical Report No. 49, (Oct. 1981).

6. Tanaka, T. , "A Model on Fire Spread in Small Scale Buildings, 2nd Report",

Building Research Institute (Japan) Research Paper No. 84, (March 1980).

7. McCaffrey, B. J. and Cox, G. , "Entrainment and Heat Flux of Buoyant

Diffusion Flames", National Bureau of Standards Report, NESIR (to be published).

8. Steckler, K. , Quintiere, J. , and Rinkinen, W. , "Flow Induced by Fire in a Compartment", National Bureau of Standards (to be published).

9. Prahl, J. , and Emmons, H. W. , Combustion and Flame , Vol. 25, No. 3,

(Dec. 1975) p. 369.

6
TABLE 1

CABIN TEMPERATURE DEPENDENCE ON POOL FIRE AND CABIN FIRE

Pool fire

Area

(m )

Cabin fire •Q_

(Iw)

Pool fire

enters cabin

(s)

Corresponding

cabin temperature

(°C)

Cabin temperature

at 240s

(°c)

4.5 2100 OO - 390

4. 5 2520 70 390 480

4.5 2940 85 400 540

6.0 420 OO 150

6.0 840 CO - 230

6.0 1260 CO - 290

6.0 1680 GO - 350

6.0 2100 OO - 390

6.0 2520 OO - 440

6.0 2940 90 420 540

7
Figure

1

-

Aircraft

Cabin

Schematic
1800

1600

1400

1200

1000

800

600

400

200

0

re 2

- Cabin Temperature Due to Wind and External Fire

9
Figure

3

-

Prediction

of

Cabin

Temperature

for

an

External

Fire

Under

Wind

Conditions
x>c

•H3o2

03

S-* pup

•HrC

03 U

03p

03

03

5-i OO

P03P

5-i 03KWo

+->

033O

03Ua

03

5-i 03aE

0) HpH

03 U

03

03 •Uu

*H03

03

5-i P-I <r

03

5-i 3

bO

•H

pL,

ImI 3anivn3dW3i Niavo
Cabin

mp

4.5 m

2 pool fire

EXIT DOOR FLOWS (kg/s) FIRE DOOR FLOWS (kg/s)

Smoke Air Air or pool fire gases

Smoke

Figure 5 - Predicted Cabin Fire Induced Flows for 4.5 m Pool Fire

12
CABIN

TEMPERATURE

|K]

SMOKE

LAYER

HEIGHT

|m)

Figure 6 - Predicted Cabin Temperature and Smoke Layer Height for 6.0 Pool Fire

and Various Cabin Fires

13
6 m2 pool fire

EXIT DOOR FLOWS (kg/s) FIRE DOOR FLOWS (kg/s)

Smoke Air Air or Smoke

pool fire gases

Figure 7 - Predicted Cabin Fire Induced Flows for a 6 m

2 Pool Fire

14
APPENDIX

ESTIMATING DOORWAY MASS FLOW RATES BY TEMPERATURE DATA

It has been shown, for room openings of conventional sizes, that a hydraulics flow model is appropriate for estimating the flow rates [9]. The

study by Prahl and Emmons [9] and the recent work of Steckler [8] show that

the required flow coefficient for this calculation is 0.7 to within about 15

percent. Moreover, the pressure distribution in a compartment subject to a fire is governed principally by hydrostatics. Therefore the flow across an opening may be determined from temperature data alone and more generally with

the additional measurement of a single pressure difference across the opening.

This will be described and illustrated below. A vertical opening will be

considered but a similar procedure could be applied to a horizontal opening.

Figure A-l illustrates a vertical opening with known temperature distribution on each side - referred to as "inside” (i) and "outside" (o) for

labeling purposes.

The pressure drives the flow across the opening (except for openings that are "large" relative to the enclosure surface area), and is given by hydrostatics,

The pressure drop across the opening for any height z is

o Ap(z) = p . ( z

) —p (z) = Ap. (z ) -

l o 10 o lO i:

[p

o (z)-pi

(z) ]gdz (A-l)

A reference pressure difference Ap . (z ) must be measured in general. However

if the position of flow reversal (i?e. ?he neutral plane height N) is known,

then Ap^(N) = 0 is the reference pressure. In some cases, N can be determined

from temperature measurements in the plane of the opening.

The rate of mass flow, with flow from i to o taken as positive in sign,

is given as

m. = CW

10 o

Pd

(z) V dz (A-2)

where W is the width of the opening

C°is 0.7

p^ is the density at the opening (and may be approximated as p^ or

P

q

at the corresponding height z)

The limits of integration depend of the sign of Ap . .

A-l
TABLE A-l LIMITS OF INTEGRATION

Ap . >0

lO

for all z

Ap . >0 and < 0

lO

(Ap . = 0 at z = N) lO

Ap . <0

lO

for all z

Z

1 0 0 N 0

Z

2 Ho N H H

o m

.

lO + + —

These limits for usual cases are given in Table A-l. The natural ventilation

case for a single opening has a change in sign for Ap . and therefore flow

is both in (-) and out (+) . The other conditions wou!8 apply for cases of

multiple openings, wind or forced ventilation. The idealized velocity is given

by Bernoulli's equation assuming the streamline density is the value at the

opening (p d

)

2|Ap (z)| 1/2

V(z) = sgn (Ap.

o

) (A-3)

d

The final equation needed is an equation of state which is

^pT =p T = constant. (A-4)

^OO 00 v

This is applicable to fire related situations since changes in absolute

pressure level are small.

The case of natural ventilation for a single opening in which the fuel

supply rate is small relative to flow rate through the opening is a typical room fire condition. If the outside temperature is uniform, T = T^, and the

inside temperature is approximated by a step-function

/ T , z > N

T = < u

i (T

£ = T^, z < N (A- 5)

then the flow rate out and air flow rate into the room is given as

m = y C W

a 3 o

(It was also assumed

(A-6)

A comparison of the results of this calculation, based on experimentally

determined values of N and T , with the measured results of Steckler [5] are shown in Table A-2. The quaYity of the measured results was assessed by

achieving a mass balance generally within 5 per cent or less. The derivation of

the estimated results from the measured values are well within + 10 per cent.

This is far superior to attempting to measure the flow rate by a limited

number of velocity probes in a centered vertical array positioned in a room opening

,
Rate

of

Air

Flow

Estimated

from

Temperature

Data

'O

<Du3 s CO o cO •H (1) 4-4 a

co •H

B > o

<U Li a 4-1

co

T3

<UU3

CO

co

0) E

oo

'O

0)

co CO

4-1 CO w

00

A! 3 O

S3

B

Co

•H

4-1 cOu

00 3 3 00

•H *H 3 <4-1 CU 3

CL

O o o

•cr§

r-^ <r CO

O 00 in CO . • • • . • . CM o 1—1 CO vO CO 1 i 1 + + + 1

00 CO vO r-l 00 <r CO

1". VO in

m 00 vO o

vOm CM vO <r CO • • • • • • • o o o o o o o o rH o rH mT <r CO

v£> VO

m VO 1—1

Ov

m <r CM CM • • • • • • • O o o o o o o

r>. vO

m 00 o co

00 rH CM vD 1—1CO o rH rH i—1

CM rH rH 1—1

00 CO <3" vO CO CM o O CTV 00 CTv vO <r . • . . • • • 1—I

rHO o o o o o

03

Li 3 O •H O & P r = = - i—1

00 co CO rH CO

rH \ 3 \ CM 1—1 1—1

Cl CM

ON ov • 00 • CM — — m CM vO rH VO

CO

0.19

212

0.125

0.117

+6.8
N BS°1 14A (REV. 2-80

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO. NBSIR 82-2537

2. Performing Organ. Report No

DOT/FAA/ CT-82/107

3. Publication Date

July 1982

4.

TITLE AND SUBTITLE

An Assessment of Correlations Between Laboratory and Full-Scale

Experiments for the FAA Aircraft Fire Safety Program, Part 5: Some Analyses of the

Post Crash Fire Scenario

5.

AUTHOR(S)

James G. Quintiere & T. Tanaka

6.

PERFORMING ORGANIZATION (If joint or other than NBS, see in struction s)

national bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8. Type of Report & Period Covered

9.

SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP)

Federal Aviation Administration

Technical Center

Atlantic City, N.J. 08405

10.

SUPPLEMENTARY NOTES

H 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

bibliography or literature survey, mention it here) ^

attempt ±s made tQ devel0 p mathematical

predictions for various aspects of the dynamics of post-crash aircraft fires. The

basis of the analysis is the experimental simulation scenario under study by the

FAA. The effects of wind are considered as well as the effect of interior and

exterior fires. Suggestions are presented for estimating cabin door flow rates

from measured temperatures.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons)

Aircraft compartments; aircraft fires; flow rates; mathematical models; wind effects.

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