A111DE 43L4E7

NATL INST OF STANDARDS & TECH R.I.C.

All 102436427

Steckler, Kenneth D/Salt water modeling QC100 .U56 NO. 86-3327 V1986 C.2 NBS-PUB- Salt Water Modeling of Fire

Induced Flows in Multicompartment

Enclosures

Reference

PUBLICATIONS

K.D. Steckler

H.R. Baum

J.G. Quintiere

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

March 1986

~QC

100

- U 5 6

86-3327

1986

red in part by:

Taylor Naval Ship Research

Development Center

sda, MD

ms

RESEARCH mFOSMATIOH

CENTOS

NBSIR 86-3327

i «

/

SALT WATER MODELING OF FIRE

INDUCED FLOWS IN MULTICOMPARTMENT

ENCLOSURES

K.D. Steckler

H.R. Baum

J.G. Quintiere

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

March 1986

Sponsored in part by:

David Taylor Naval Ship Research

and Development Center

Bethesda, MD

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

NATIONAL BUREAU OF STANDARDS. Ernest Ambler, Director

TABLE OF CONTENTS

Page

LIST OF FIGURES iv

NOMENCLATURE . vi

Abstract 1

1. INTRODUCTION 1

2. ELEMENTS OF SALT WATER MODELING 3

3. MATHEMATICAL FORMULATION 4

3.1 Governing Equations 4

3.2 Plume Reynolds Number 8

3.3 Plume Momentum 8

3.4 Plume Mass Flux 9

3.5 Source Geometry 9

3.6 Boundary Conditions 10

4. EXPERIMENTAL TECHNIQUE 10

5. EXPERIMENTAL RESULTS AND DISCUSSION 11

5.1 Multiroom Single-Story Structure 11

5.2 Multicorapartraent Multideck Ship 13

6. CONCLUSIONS 14

7. ACKNOWLEDGMENTS 14

8. REFERENCES 14

APPENDIX A. Results for Positions A and D in Multiroom Single-Story

Structure 25

APPENDIX B. Photographs of Ship Experiments 34

-iii-
LIST OF FIGURES

Page

Figure 1. Enclosures; (a) full-scale with heat source,

(b) reduced-scale with salt water source 16

Figure 2. Experimental arrangement 17

Figure 3. Plan of full-scale test facility showing four test

configurations 18

Figure 4. Results for position E, 1/2 corridor configuration 19

Figure 5. Results for position E, 3/4 corridor configuration 20

Figure 6. Results for position E, full corridor configuration 21

Figure 7. Results for position E, full corridor plus lobby

configuration 22

Figure 8. Inverted photographs of transient salt water flows in room and corridor 23

Figure 9. Inverted photograph of ship experiment approximately

450 s after activation of source 24

Figure A-l. Results for position A, 1/2 corridor configuration 26

Figure A-2 . Results for position D, 1/2 corridor configuration 27

Figure A-3. Results for position A, 3/4 corridor configuration 28

Figure A-4. Results for position D, 3/4 corridor configuration 29

Figure A-5. Results for position A, full corridor configuration 30

Figure A-6. Results for position D, full corridor configuration 31

Figure A-7. Results for position A, full corridor plus lobby

configuration 32

Figure A-8. Results for position D, full corridor plus lobby

configuration 33

Figure B-l. Inverted photograph of ship experiment approximately

40 s after activation of source in crew quarters 35

Figure B-2. Ship experiment approximately 120 s after activation of source in crew quarters 3b

Figure B-3. Ship experiment approximately 240 s after activation of source in crew quarters 37

-iv-
LIST OF FIGURES (continued)

Page

Figure B-4. Ship experiment approximately 360 s after activation of

source in crew quarters . 38

Figure B-5. Ship experiment a few seconds after activation of source

in machinery space 39

Figure B-6. Ship experiment approximately 8 s after activation of source in machinery space 40

Figure B-7. Ship experiment approximately 40 s after activation of source in machinery space 41

Figure B-8. Ship experiment approximately 70 s after activation of source in machinery space 42

Figure B-9. Ship experiment approximately 240 s after activation of source in machinery space 43

Figure B-10. Ship experiment approximately 300 s after activation of source in machinery space 44
NOMENCLATURE

V

F

G

g

H

h

k

k

L

a

•ra o

P

P

Pr

0Q

oRe

Sc

T

T

o

t

U

u

v

o

X

specific heat of air

mass diffusivity of salt water in fresh water

ratio of salt water plume's initial momentum flux to buoyancy

flux, Eq . (16)

ratio of length scales cubed, Eq. (15)

gravitational acceleration

full-scale enclosure height

reduced-scale enclosure (model) height

thermal conductivity of air

vertical unit vector; either upward or downward

characteristic length of heat source

characteristic length of salt water source

mass release rate of salt

pressure perturbation about hydrostatic pressure

Pr or Sc, Eq. (13)

Prandtl number for air, Eq. (13)

heat release rate

Reynolds number, Eq. (14)

Schmidt number for salt water in fresh water, Eq . (13)

temperature

initial temperature

time

velocity scale, Eq. (11)

velocity

velocity of salt water at source exit

position vector

-vi-
Y salt mass fraction, (p - p )/p

o o

z distance from source measured along flow path

z' distance at which initial momentum effect becomes small

height of interface between upper hot gas (salt water) layer and

lower cool gas (fresh water) layer

S density or temperature perturbation scale, Eq. (12)

p density

P^ initial density of fluid in enclosure

0 nondimensional temperature, (T - T

Q )/T , or mass fraction, Y

u viscosity of air or fresh water

Superscripts

* nondimensionalized variable or operator, Eqs. (4-10)

* '

' per unit volume

-vii-

SALT WATER MODELING OF FIRE INDUCED FLOWS

IN MULTICOMPARTMENT ENCLOSURES

K.D. Steckler, H.R. Baum, and J.G. Quintiere

Abstract

Salt water modeling is used to study fire-induced flows in

multicompartment structures. Scaling laws relating salt water flows and hot

gas flows are developed. Results from 1/20 scale salt water simulations of

fire-induced flows in a single-story multiroom structure are shown to be in

good agreement with available full-scale results. Experiments involving a

1/20 scale model of a U.S. Navy ship demonstrate the feasibility of using the

technique to study hot gas flows in compartraented structures too complex to

study economically by other means.

Key words: buoyant flow; corridors; flow visualization; salt water;

scale models; scaling laws; smoke filling; smoke layers.

1 . INTRODUCTION

A major threat to the safety of inhabitants of many multiroom and

multistory structures containing a localized fire is the rapid flow of combustion products throughout the structure. The paths of these flows are often

complex; for example, through a series of connecting doorways, halls, stairs,

shafts, etc. The time-dependent position of the hot layer fronts, layer

thicknesses, and concentrations are needed to assess the threat to life safety

along these complex paths.

- 1 -
Several alternative approaches can be considered to elucidate and

understand fire generated flows in complex structures. Full-scale experiments

offer the most realistic approach, but they are expensive and difficult to

instrument and analyze. Reduced-scale fire experiments can reduce cost, but

present the same instrumentation problems as in full-scale. In principle,

mathematical solution of the partial differential equations of fire and flow

physics should enable the determination of fire phenomena in enclosures. But

issues of turbulence modeling are not fully resolved and three-dimensional

unsteady flow in complex geometries is still not practical using even the

largest available computers. Less fundamental mathematical lumped-parameter

or "zone" models [1] reduce the mathematical complexity of the mul ticorapar tment problem by treating the structure as a limited number of connected

spatial zones. Their solution is amenable to common computers, but with no

guarantee to their physical accuracy or completeness. Indeed, mixing between

zones is only partially addressed, and no explicit attention is given to the

time-dependent development of horizontal flows in large rooms and long

corridors, and the development of vertical flows in tall shafts. One approach

that physically models most of the flow characteristics and provides a clean

environment for measurement with excellent flow visualization is the hydraulic

analog technique known as salt water modeling. Moreover, this technique

provides a relatively inexpensive approach for evaluating complex structures.

Salt water modeling substitutes turbulent buoyant salt water moving in

fresh water for turbulent buoyant hot gas moving in cold gas. Since the

driving phenomena for the two processes are identical — buoyancy forces

resulting from density differences — the two processes can be related when

viscous and heat transfer effects are small. Although this technique offers

-2 -
great potential in fire modeling, it has neither been used much nor has it

been well documented. Thomas et al. [2] used the salt water technique to show

the effect of roof and side vents on clearing smoke from large rooms. Tangren

et al. [3] applied the technique at 1/5 scale to study the densities and

positions of hot gas layers produced by fires in a room with a doorway or

window vent.

The current study was motivated by the desire to evaluate smoke movement

in naval combat ships. The availability from the U.S. Navy of detailed 1/20

scale clear plastic ship models — originally built for stress studies — and

large water tanks for laboratory testing presented a natural application for

salt-water modeling. Moreover, a ship's structure contains many generic flow

passages so as to make its study generally applicable. To establish a sound

basis for use of the modeling technique in ship and other raultiroom structures, a comparison was made between the salt-water analog and single-story

full-scale multiroom fire experiment results. These salt water experiments

were conducted at the same scale (1/20) as the ship model. Specifically, the

time-dependent positions of the hot gas layers and their thicknesses were

measured. These comparisons and a derivation of the governing equations with

considerations needed to fulfill the requirements of the partial scaling

relations will be presented. Finally, typical results from experiments

conducted with a model of a U.S. Navy frigate will be presented.

2. ELEMENTS OF SALT WATER MODELING

Salt water modeling involves (1) formulating reasonably precise

mathematical treatments of smoke and salt water flows, (2) choosing appro-

- 3 -
priate nondimensionalizing factors to reduce the two mathematical treatments

to precisely the same form, (3) performing a salt water experiment in a scale

model, taking care to insure that the salt water is injected so as to form a

turbulent buoyancy-dominated plume, and (4) interpreting the salt water

results in terms of full-scale smoke movement via the analysis that led to the

reduced forms of the equations. These steps establish the salt water experiment as an analog computer for solving full-scale smoke flow problems.

3. MATHEMATICAL FORMULATION

The theoretical basis for the salt water technique entails consideration

of the governing equations for hot gas and salt water flows, source conditions, boundary conditions, and attendant approximations. Approximations are

made so as to establish the partial scaling relations on the scale of the

enclosure height, not on the scale of the source. Indeed, it will be shown

that salt water modeling does not apply on the scale of the source owing to

inherent differences between fire and salt water source conditions. Nevertheless, the initial effects become small at some distance from the source and

the analogy is quite good beyond this distance.

3.1 Governing Equations

Baum and Rehm [4,5] derived nondimensional governing equations for the

flow of invisid thermally nonconducting gas within an enclosure heated by a

source sufficiently weak for the Boussinesq approximation to be valid for Onflow outside the source region. They expressed the nondimensional variables

in terms of a length scale H, the enclosure height; a length scale L, the

-4-
spatial extent of the source, shown in Fig. la; a velocity scale U, defined

below; and a density (or temperature) perturbation scale £, also defined

below, where U and C were chosen to make the convective and buoyancy terms in

the momentum equation of the same order. These equations are shown below with

appropriate viscous and heat conduction terms added to facilitate later

discussion of Reynolds number, Re, considerations pertinent to the current

s tudy.

*V

_*

• u = 0 ( 1 )

—*

D,, *— *9 —

—— +Vp - 0 k = (1/Re) V u

Dt

*

nfl * *? * ^ = GQ + (1/ReP) V

Z

0 Dt

( 2 )

(3)

The symbols in these equations are defined by the left sides of the following

scaling equations:

hot gas salt water

HV = V = hV (4)

x /H = x*

g x /h

s (5)

t U/H = t g

t U/h

s

( 6 )

u/U = u = u/U (7)

~ 2 p/P U = p

o p/p Uo

( 8 )

- 5 -
hot gas salt water

(l - T )/T £ o o

Q"7(Q /L3

) = 1

= 0

= Q

(q g/p c T h)

o o p o = U

U

2 /gH = C

Me /k = Pr

P = P

P UH/m = Re

o

(H/L) 3 = G

= Y/C

= 1 = m’ ' '/(m /£

3

) o

= (6

og/Po

h)

- l^/gh

= Sc = m/p V

o

= P Uh/M

o

= (hM)3

(9)

( 10 )

(ID

( 12 )

(13)

(14)

(15)

Equations (1-3) represent conservation of mass, momentum, and energy,

respectively, at a point x in the gas away from enclosure surfaces at time

§

tg. The gas at with velocity u, temperature T, specific heat c

p

, thermal

conductivity, k, and viscosity M is driven by a volumetric heat source

* • , 3

• Q

r T * = Q /L , where Q is the heat release rate and L characterizes the region

o o in which it is released. The pressure is considered to be the sum of the

hydrostatic pressure, which is a function of the initial density p^ (and

therefore constant), and a pressure perturbation p. The magnitude of gravitational acceleration is denoted by g and the initial gas temperature by T

Q

.

k is a unit vector in the upward direction. The nondimensional variables

x* , t* , and 0*, shown on the left sides of Eqs. (5), (6), and (9) are

identical to those used by Heskestad [6] to analyze full-scale fire experiments [7] in which fire strength was varied within a given enclosure.

- 6 -
The mathematical description of salt water flow in fresh water is formulated in a similar fashion. Figure lb shows an inverted reduced-scale

geometrically similar model of the enclosure mentioned in the above formulation of the gas flow equations. The reduced-scale model has a height h and is

initially filled with fresh water. It contains a salt water source at coordinates scaled to correspond to those of the full-scale heat source. For a salt

water source witthr" spatial extent l, the governing equations for the flow of

weakly buoyant salt water in fresh water can be nondimensionalized, in the

manner described above, to the forms given by Eqs. (1-3). The symbols in

these equations are now defined by the right sides of Eqs. (4-15). In this

case, Eqs. (1-3) represent conservation of total mass, momentum, and salt

mass, respectively, at a point x

g in the liquid away from the enclosure

surfaces at time t

g

. The liquid at point x

g with velocity u, salt mass

fraction Y, mass diffusivity V , and viscosity y is driven by a pressure

~ 3 perturbation p caused by a volumetric salt water source m' '

= m /i , where

o m

Q

is the mass release rate of salt and l characterizes the region in which it

is released. The density of fresh water is denoted by P and £ is a unit

o vector in the downward direction.

Since the nondimensional forms of the salt water and hot gas governing

equations are identical, their solutions in terms of nondimensional variables

are identical when G, Re, and P are preserved according to Eqs. (13-15). In

practice, however, it is impossible to match these quantities in all cases.

Nevertheless, inconsistencies can be minimized by careful selection of the

salt water source conditions. The major requirement to keep in mind is that

the salt water plume simulate the key features of a turbulent buoyant fire

plume. Beyond this requirement, the specific gravity (density) and flow rate

- 7 -
of the salt water source are not critical. Indeed, the value of the scaling

analysis is that the results from one salt water experiment can be used in

Eqs. (5-12) to predict the results for other salt water source conditions or

heat releae rates in geometrically similar enclosures.

3.2 Plume Reynolds Number

Turbulent fire plumes have Reynolds numbers, defined by Eq . (14), on the

order of 10^. This value is sometimes difficult to match in reduced-scale

salt water experiments due to the reduced length scale and source restrictions

described below. Nevertheless, turbulent plumes exist for Reynolds numbers

down to ~ 10

4

. When the Reynolds number is this large or larger, the

molecular transport terms in Eqs. (2) and (3) become negligible in relation to

the other terms and inconsistencies between Prandtl number for air, Pr, and

Schmidt number for salt water in fresh water, Sc, become unimportant.

4

Therefore, when the Reynolds number or the salt water plume is ~ 10 or

larger, Eqs. (1-3) are essentially identical for hot gas and salt water flows

and dimensional variables, such as x^ and x

g or tg and t s , are related through

Eqs. (5-12).

3.3 Plume Momentum

In real fires the turbulent hot gas plume is usually purely buoyant, with

virtually no initial momentum flux. In contrast, the salt water must be

introduced with some initial momentum. Operationally, this requires a compromise; the salt water flow rate must be large enough to produce a turbulent

plume (large Re) but small enough to insure that buoyancy effects dominate

-8 -
initial momentum effects over a large portion of the plume height. Following

Tangren et al. [3], the effect of initial momentum is assessed in the current

study by considering the ratio F of initial momentum flux to buoyancy flux at

height z "above" the source; that is,

F = Pv

2 /2 (p - P ) gz (16)

o o

where v

Q is the velocity at the source exit and p and P q are the density of

salt water and fresh water, respectively. At some distance z = z', the

initial momentum effect becomes small and a purely buoyant plume is approximated beyond z*.

3.4 Plume Mass Flux

The mass flux in a fire plume is large compared to the mass issuing from

the source. Therefore, care must be taken in the salt water experiment to

insure that the source mass flow (salt plus water) is small compared to the

mass flow in the plume at some distance from the source; for example, at the

ceiling "above" a simulated pool fire. In the current study, a point source

plume model [3] is used to estimate plume mass flow.

3.5 Source Geometry

Fire is a volumetric heat source with a constantly changing, poorly

defined spatial extent. As it is impossible to release salt in a precisely

scaled volume corresponding to the full-scale situation, the condition set

forth in Eq . (15) cannot be met precisely. Nevertheless, this condition can

-9 -
be partially met by considering L as the diameter of the full-scale fire

and £ = (h/H)L as the diameter of the planar salt water source.

3.6 Boundary Conditions

The previous justification for disregarding viscous and heat transfer

effects does not apply to regions near the enclosure boundaries. When the

Reynolds number of the salt water flow does not match that of the hot gas

flow, drag effects, which are a weak function of Re, are not precisely simulated. A more serious limitation, however, is the inability of the salt water

experiment to simulate heat transfer — by means of salt transfer — at the

boundary surfaces. Consequently, buoyancy is maintained for a longer period

in the simulation than in the full-scale situation. Since buoyancy drives the

flow, the salt water results are conservative in the sense that the speed and

spatial extent of the salt water flow in a complex structure are somewhat

greater than would exist in a real fire situation.

4. EXPERIMENTAL TECHNIQUE

Figure 2 shows an inverted scale model of the structure of interest

initially filled with fresh water. The model contains a salt water source

consisting of a short length of 1.9 cm I.D. pipe filled with glass beads. The

lower end of the pipe is covered with a piece of cloth to keep the beads in

place. The source is connected through a flowrator to an open tank of dyed

salt water, which has a specific gravity of 1.07 (10 percent NaCl by weight),

located above the model. An experiment consists of flowing the salt water

through the source at an appropriate rate while video cameras equipped with

time base generators record the resulting flow on video tape.

- 10-
5. EXPERIMENTAL RESULTS AND DISCUSSION

5.1 Multiroom Single-Story Structure

A 1/20 scale inverted clear plastic model of the full-scale test facility

shown in Fig. 3 was constructed for the salt water experiments. The reducedscale model was equipped with removable partitions to alter the length of the

corridor as shown in this figure. This choice of geometry allowed comparison

of salt water results with hot gas results obtained earlier by Cooper et al.

[7] in the full-scale structure. They used a methane diffusion burner located

near the floor and at the center of the burn room. Separate tests were

conducted with the burner operating at 25, 100, and 225 kW. Layer interface

heights versus time results were reported for the locations designated by the

letters in Fig. 3. They defined the interface height as the height at which

the temperature increase above ambient temperature was 10 percent of the

temperature increase measured near the ceiling. These heights and times were

then nondimensionalized according to the left sides of Eqs. (5) and (6).

Typical results are shown as open symbols in Figs. 4 to 7. An equivalent

scaling analysis of these full-scale data has been presented by Heskestad [6].

The 1/20 scale model was initially filled with fresh water to the level

of a scaled vent which corresponded to the small slot vent at the floor of the

full-scale facility. This vent maintained the liquid at the initial level

throughout the experiment. The height of each compartment was 12.7 cm. The

salt water source was mounted over the center of the "burn room" with its

cloth-covered end facing downward and positioned just below the surface of the

water. Since each of the full-scale experiments was conducted with a constant

- 11 -
fuel supply rate, the salt water was introduced at a constant flow rate and

the subsequent flow throughout the model recorded on video tape. Typical flow

patterns are shown in Fig. 8. The layer interface height versus time data at

the locations identified by letters in Fig. 3 were taken from the video tape

and nondimensionalized according to the right sides of Eqs. (5) and (6).

Source effects were evaluated in a preliminary series of experiments

involving source flow rates in the range 20 to 60 ml( solutions) /s . Rates in

the range 40 to 60 ml/s produced the best agreement with the full-scale

results. At the center of this range, 50 ml/s, the Reynolds number is 9500,

and from Eq. (16), F = 1.0 at z = 0.19 h, and F = 0.19 at z = h. Therefore

the plume is turbulent and buoyancy flux exceeds initial momentum flux over 80

percent of the plume height. A calculation, based on point source plume

theory [3], indicates that the buoyant mass flow rate in the plume at the

ceiling is four times the source flow rate. Consequently, the 50 ml/s flow

rate produces a reasonable approximation to a purely buoyant plume over the

height of the compartment h = 0.127 m. Flow rates below 40 ml/s tended to be

too laminar to produce a good simulation of a fire plume. Consequently, all

subsequent experiments were conducted at ~ 50 ml(solutions)/s (~5 g(salt)/s).

Typical salt water results are displayed as solid symbols in Figs. 4 to

7. Each figure demonstrates the ability of a single 1/20 scale salt water

experiment to predict full-scale results in a geometrically similar enclosure

for a range of fire strengths . Similar agreements between salt water and

full-scale results for positions A and D are shown in Appendix A.

- 12 -
5.2 Multicompartment Multideck Ship

Since the 1/20 scale model of the Navy FFG-7 class frigate included

numerous vents to the outside, experiments were conducted with the inverted

model submerged in a large tank of fresh water. The heights of the smaller

compartments in the ship were ~ 13 cm. Salt water sources were installed at

two locations; one in a crew quarters located in the lower mid-section of the

ship, and the other in a machinery space at the same level but located closer

to the stern. All hatches, interior and exterior, were fully open.

Salt water was supplied to one of the sources at a constant rate of

50 ml/s and the subsequent flow throughout the ship was recorded on video

tape. Figure 9 shows an inverted photograph of the ship approximately 450 s

after activating the source in the crew quarters. The dyed salt water has

spread through a large portion of the deck house and to the outside through

exterior vents. Below the main deck, the flow is confined to the space

between watertight bulkheads.

Equations (5) and (6) allow the results in Fig. 9 to be interpreted in

terms of full-scale hot gas flows. The expression for t relates the experimental time t and mass flow of salt ra to full-scale time t„ and heat release s o g

rate Q . For example, the conditions shown in Fig. 9 at t = 450 s represent

o s full-scale conditions at t„ = 450 s when the full-scale heat release rate is

o 225 kW. Times to reach the same conditions at other heat release rates are

easily calculated via the expression for t , Eq . (6). Additional photographs

of the ship experiments are presented in Appendix B.

- 13 -
6.

CONCLUSIONS

Scaling relations connecting reduced-scale salt water flows to full-scale

hot gas flows have been developed. The scaling relations for position and

time have been partially validated for four specific geometrical arrangements

through comparisons of layer interface heights obtained in 1/20 scale salt

water experiments and full-scale fire-induced flow experiments. Experiments

involving a complex ship model have demonstrated the feasibility of using the

salt water technique to investigate hot gas flows in structures too complex to

study economically by other means.

7.

ACKNOWLEDGMENTS

This work was sponsored in part by David Taylor Naval Ship Research and

Development Center (DTNSRDC), Bethesda, MD under contract N00167-84WRA-0207 .

The authors would like to thank Messrs. W. Rinkinen and H. Wheelock of the

National Bureau of Standards and Mr. G. Sikora of the DTNSRDC for their

assistance with the experiments and data reduction.

8. REFERENCES

[1] Jones, W.W., Fire Safety Journal, 9, 55-59 (1985).

[2] Thomas, P.H. , Hinkley, P.L. , Theobald, C.R. , and Simms, D.L.,

Investigations into the Flow of Hot Gases in Roof Venting, F.K. Technical

Report No. 7, Dept, of Scientific and Industrial Research and Fire

Offices’ Committee Joint Fire Research Organization, London, 1963.

[3] Tangren, E.N., Sargent, W.S., and Zukoski, E.E., Hydraulic and Numerical

Modeling of Room Fires, NSF Grant ENV 76-06660 and U. S. Dept, of

Commerce, Nat. Bur. of Stand. Grant 5-9004, California Institute of

Technology, Pasedena, CA, June 1978.

- 14 -
[4] Baum, H.R. and Rehm, R.G., Combustion Science and Technology, 40, 55-77

(1984).

[5] Rehm, R.G. and Baum, H.R., National Bureau of Standards Journal of

Research, 83, 297 (1978).

[6] Heskestad, G. , Physical Modeling of Smoke Movement, presented at ASTM E-5

Committee Meeting, Research Review Seminar on "Highlights of E-5’s First

80 Years", Williamsburg, VA, December 9-14, 1984.

[7] Cooper, L.Y., Harkleroad, M. , Quintiere, J. , and Rinkinen, W. , An

Experimental Study of Upper Hot Layer Stratification in Full-Scale

Multiroom Fire Scenarios, Paper 81-HT-9, 20th Joint ASME/AIChE National

Heat Transfer Conference, Milwaukee, WI , August 2-5, 1981.

- 15 -
Fig. 1. Enclosures; (a) full-scale with heat source, (b) redund-s. a K- with salt water source.

-16-
EXPERIMENTAL

TECHNIQUE

Fig.

2.

Experimental

arrangement.
-18'

3/4

CORRIDOR

51.6

m

2

1/2

CORRIDOR

40.6

m
1/2

CORRIDOR,

POSITION

E

O

*

rco

•HU

!-i 3M

•HC

co

D

CO

cu Pi

oc

•H

* P Z ‘1HOI3H 30VJU31NI 1VNOISN3WIC1NON

-19-

NONDIMENSION

AL

TIME
3/4

CORRIDOR,

POSITION

E

O

eg

o

eg

eg

O

O

eg

o

ooo

CO

o

o

eg

O

O

O

ooo

coo

o

eg

o

*

c

o

00

1-3

OC •H4*

3

J>V

ai

uO

oi

* P Z ‘1HOI3H aOVdU3J.NI nVNOISNaWIQNON

- 20-

NONDIMEN

SION

AL

TIME,
FULL

CORRIDOR,

POSITION

E

O

CM

O

CM

CM

©

©

CM

©

00

O

<0

O

O

CM

O

O

O

00

O

(0

O

MO

CM

O

* p Z ‘1HOI3H 30V3U31NI “IVNOISNSIAIIQNON

- 21-

NONDIMENSION

AL

TIME,

t*

Fig.

6.

Results

for

position

E,

full

corridor

configuration.
FULL

CORRIDOR

&

LOBBY,

POSITION

E

Oo CO <0

s CM

• O

1- 0 0 0 0

*

P Z ‘J.HDI3H 30VdH3J.NI 1VN0ISN3WICIN0N

- 22-

NONDIMEN

SION

AL

TIME,
-23

Fig.

8.

Inverted

photographs

(g

upward)

of

transient

salt

water

flow

in

room

and

corridor.

Lobby

is

on

right.
-2kFig.

9.

Inverted

photograph

(g

upward)

of

ship

experiment

approximately

450

s

after

activation

of

source.

Bow

is

on

right.
APPENDIX A

Results for Positions A and D in Multiroom Single-Storey Structure

- 25-
1/2

CORRIDOR,

POSITION

A

O

*

P Z ‘1HDI3H 30VdU3±NI -1VNOISN3IAIIQNON

-26-

NONDIMENS

ION

AL

TIME,

t*

Results

for

position

A,

1/2

corridor

configuration.
1/2

CORRIDOR,

POSITION

D

O

* P Z ‘1HDI3H 30VJU31NI 1VNOISN3l/\IIC]NON

-27 -

NONDIMENSION

AL

TIME,

t*

Fig.

A-2.

Results

for

position

D,

1/2

corridor

configuration.
3/4

CORRIDOR,

POSITION

A

O

*

c

0

(CLK

-28-

NONDIMENSION

AL

TIME,
3/4

CORRIDOR,

POSITION

D

o o o o

o

CM

O

CM

CM

O

O

CM

O

CO

O

<0

O

o

CM

O

O

O

CO

O

(0

o

o

CM

O

* P Z ‘JLHDI3H 30Vdd31NI “IVN0ISN3IAIIQN0N

- 29-

NONDIMENSION

AL

TIME,

t*

Fig.

A-4

.

Results

for

position

D,

3/4

corridor

configuration
FULL

CORRIDOR,

POSITION

D

O

^fr Osl O

CM

CM

O

O

CM

O

CO

O

CO

O

o

CM

O

O

O

CO

o

(0

o

o

CM

O

* P Z ‘1H0I3H 30Vda31NI “1VN0ISN3IAIIQN0N

lO

I <

oc

- 30-

NONDIMENSION

AL

TIME,

t*

Results

for

position

A,

full

corridor

configuration.
FULL

CORRIDOR,

POSITION

A

O

CM

O

CM

CM

O

O

CM

O

00

O

<0

O

O

CM

O

O

O

00

O

(0

O

CM

*

P Z ‘1H0I3H BOVdUBlNI IVNOISNaiAIIQNON

- 31-

NONDIMENSION

AL

TIME,

t*

Figure

A-6.

Results

for

position

D,

full

corridor

configuration.
FULL

CORRIDOR

&

LOBBY,

POSITION

A

O

O CO

• CO

• • OJ

• o

o o o o

*

rv3

cr. co

o

>>

-O

-Oo

o

<+-

1/1 +J3

i/> ai oc

i

at

s-3

cn

* p Z ‘1H0I3H 30VdU3J.NI 1VN0ISN3WI0N0N

-32-

NONDIMENSION

AL

TIME,
FULL

CORRIDOR

&

LOBBY,

POSITION

D

o

* p z ‘ihoi 3H aovauaiNi ivNOiSNawiaNON

- 33-

NONDIMENSION

AL

TIME,

t*

Figure

A-8.

Results

for

position

D,

full

corridor

plus

lobby

configuration.
APPENDIX B

Photographs of Ship Experiments
- 35-

Figure

B-l

.

Inverted

photograph

of

ship

experiment

approximately

40s

after

activation

of

"225

kW"

source

in

crew

quarters.

Bow

is

on

righ
36

Figure

B-2.

Ship

experiment

approximately

120

s

after

activation

of

"225

kW

source

in

crew

quarters.

Bow

is

to

the

right,
- 37-

Figure

B-3.

Ship

experiment

approximately

240

s

after

activation

of

"225

kW

source

in

crew

quarters.

Bow

is

on

the

right.
- 38.

Figure

B-4.

Ship

experiment

approximately

360

s

after

activation

of

"225

kW

source

in

crew

quarters.

Bow

is

to

the

right.
39

Figure

B-5.

Ship

experiment

a

few

seconds

after

activation

of

source

in

machinery

space.

Stern

is

on

the

left.
-UoFigure

B-6.

Ship

experiment

approximately

8

s

after

activation

of

"225

kW"

source

in

machinery

space.

Stern

is

on

the

left.
- 1* 1-

Figure

B-7.

Ship

experiment

approximately

40s

after

activation

of

"225

kW"

source

in

machinery

space.

Salt

water

flow

has

entered

helicoptor

hangers

above

the

main

desk.

Stern

is

on

the

left,
- 42-

Figure

B-8.

Ship

experiment

approximately

70s

after

activation

of

"225

kW"

source

in

machinery

space.

Salt

water

flow

is

just

beginning

to

emerge

from

helicopter

hanger

doorways

on

the

left.
-1+3-

Figure

B-9.

Ship

experiment

approximately

240

s

after

activation

of

M

225

kW"

source

in

machinery

space.
-UUFigure

B-10.

Ship

experiment

approximately

300

s

after

activation

of

"225

kW"

source

in

machinery

space.
NBS-114A (REV. 2-80

U.s. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR-86/3327

2. Performing Organ. Report No, 3. Publication Date March 1986

4. TITLE AND SUBTITLE

Salt Water Modeling of Fire Induced Flows in Multicompartraent Enclosures

5. AUTHOR(S)

K.D. Steckler, H.R. Baum, J.G, Quintiere

6. PERFORMING ORGANIZATION (If joint or other than NBS, see instructions)

national bureau of standards

DEPARTMENT OF COMMERCE

X20 234

Gaithersburg, MD 20899

7. Contract/Grant No.

8 . Type of Report & Period Covered

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

David Taylor Naval Ship Research and Development Center

Bethesda, MD 20084

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

bibliography or literature survey, mention it here) Salt water modeling is used to study fire-induced flows in multicompartment

structures. Scaling laws relating salt water flows and hot gas flows are developed. Results from 1/20 scale salt water simulations of fire-induced

flows in a single-story multiroom structure are shown to be in good agreement

with available full-scale results. Experiments involving a 1/20 scale model

of a U.S. Navy ship demonstrate the feasibility of using the technique to study

hot gas flows in compartmented structures too complex to study economically by

other means.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) buoyant flow; corridors; flow visualization; salt water; scale models; scaling laws;

smoke filling; smoke layers

13. AVAILABILITY

[y~| Uni imiied

[33] For Official Distribution. Do Not Release to NTIS

[ H Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

' 20402.

Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

52

15. Price

$11.95

USCOMM-DC 6CU3-P80