SUPPRESSANT PERFORMANCE EVALUATION 

IN A BAFFLE-STABILIZED POOL FIRE 

William Grosshandler and Michelle Donnelly 

Building and Fire Research Laboratory 

National Institute of Standards and Technology 

Gaithersburg, MD 20x99 USA 

Rao Charagundla and Cary Presser 

Chemical Sciences and Technology Laboratory 

National Institute of Stnnd;rrds and Technology 

Gaithersburg, MD 20x99 USA 

INTRODUCTION 

Thc amount of a gaseous agent required to extinguish fires in full-scale engine nacelles varies 

greatly with the geometry of the test fixture and the manner in which the tlame is stabilized. It 

has been observed that if the test is designed to allow fuel to collect behind obstacles in the 

vicinity of a hot surface, a significantly higher mass of agent is ncce ry for sustaincd suppression. The superior performance of chemically acting agents, such as CF3Br and CF& rclative to 

a hydrotluorocarhon alternative like HFC-12.5 is also accentuated in some of these tests. Fullscale testing carried out by the Navy using two different fixtures. cach meant to simulate fires in 

the F/A-I8 engine nacelle, has led to different conclusions regarding the amount and relative 

performance of both HFC- 12.5 and solid propellant gas generator (SPGG) fire suppressants. 

The complexity and unpredictability of full-scale tests can be traced to two factors: flame stahilization and agcnt mixing. Flame stability is governed by local geometry, surface temperature, 

and fuel and air tlow patterns. Flame extinction will occur if the agent is entrained into the tlame 

zone in sufficient concentration. if the fuel and air flows are disrupted enough by the agent 

discharge process, or by a combination of thc two effects. Entrainment and localized flame 

stretch are, in turn, controlled by the way the fire suppression system is designed and by the 

location of the fire relative to the discharge nozzle. 

Hirst and Sutton 11 developed a wind tunnel to explore the impact of step height. air flow, and 

pressure on the blow-out of ajet fuel pool fire stabilized behind a backward facing step. Hirst ct 

al. [2] studied the suppression of these types of fires using various halons, and concluded that a 

liquid pool burning in a flow behind an obstacle is the most difficult fire to extinguish. This was 

born out in full-scale tests done later [3]. Expcrimcnts by Hamins et al. 141, in cooperation with 

Walter-Kidde Aerospace, were conducted in a wind tunnel scaled down from the earlier work by 

Hirst to examine the performance of HFC-I 25 and HFC-227ea. Investigations at the Air Force 

Research Laboratory [SI as part of thc Next-Generation Program (NGP) sousht to determine thc 

detailed structure. during suppression, of a noli-premixed methane/air flame stabilized behind a 

step. The changing character of the tlame with step height and air velocity was examined, along 

with the amount of Halon 1301 required to suppress the tlame as a function of the tlow 

parameter-s and injection interval. 

A turbulent spray burner was designed in earlier work at NIST [6] to simulate an engine nacelle 

spray fire resultins from ;I ruptured fuel or hydraulic fluid line. In this apparatus. the agent 

release and mixing process were well controlled, and the air flow was maintained constant with a 

sonic orifice. This arrangement allowed thc agent to be discharged without disrupting the 

incoming air. The turbulent spray burner was used with both gaseous and powdered agents. 

Hamins et al. [4] redesigned the burner to include a heated disk in the center of the tlow downHdon Opliony Technical Working Conlcrcnoc 27-29 April l9W 105 
stream of the fuel nozzle. They showed that the concentration of nitrogen necessary to extinguish a turbulent propane flame increased substantially with surface temperature. The same 

trend, but to a lesser degree, was observed with hydrofluorocarbons. 

A transient application, recirculating pool fire (TARPF) suppression facility has been developed 

in the current study to screen different agents and prototype systems, and as an indicator of fullscale performance. The TARPF agent suppression screen is designed to reproduce the most 

difficult fire situation and to allow control of critical agent discharge parameters, including agent 

discharge rate and duration, and air flow. The performance of powders, gases, and solid-propellant gas generators (SPGGs) can be examined relationships between the mass of agent necessary 

for sustained suppression, and agent injection duration, temperature of a hot surface, and obstacle 

geometry can be explored. 

EXPERIMENTAL FACILITY 

The TARPF is a small wind tunnel consisting of a number of sections (Figurel). The main 

portion is 2.5 m long with a square cross section 92 mm on a side. Air, supplied by a compressor 

rated for a maximum flow of 180 g/s at 1 .O MPa, can be delivered to the tunnel at nominal 

speeds up to 17 m/sec. Flow is monitored using a calibrated sonic orifice and a piezoelectric 

pressure transducer. A heater is available to increase the inlet air temperature to above 200 "C. 

A honeycomb flow straightener and mixing screens are located a meter upstream of the test 

section. The burner consists of a sintered bronze plate, 92 mm wide by 190 mm long. Propane 

is the fuel used in the current study, but plans include the capability to burn JP-8. Stainless steel 

baffles between 10 and 55 mm high are located upstream of the burner. A ramp can also be 

inserted to form a backward-facing step (Figure I). Heat release rates assuming complete 

combustion are up to IO kW. The flame is viewed from above and the side through 6 mm thick 

glass windows. 

, Exhaust 1 Video 

Camera 

Air 

25M) 

c I 

n rn 

^^ I - I

Figure 1. Schematic of TARPF facility. 

106 Halon Options Technical Working Conference 27-29 April 1999 
Ignition is with a spark plug located on the side wall of the test section, about 20 mm above thc 

surface of thc burner and downstream of the baffle. An electric strip heater 25 mm hy 87 mm in 

area simulates a hot surface rcignition point and produces average surface temperatures up to 

SO0 EC. The strip hcatcr can be placed in the air flow either ahead of or behind the burner. The 

JP-8 spray nozzle, when it is added, will be positioned to ensure that liquid fuel will impinge on 

the strip heater. 

Thc firc suppressing agent is injccted downstream of the air metering orificc. Since the llow is 

choked in the metering orifice plate, the introduction of the agent can be accomplished without 

altering the total air flow. This is particularly critical when trying to distinguish chemical from 

physical modes of extinction. Mixing of the agent with the air is facilitated by iiijecting the 

agent through two opposed radial ports into the reduced diameter entrance region. 

One and/or two-liter pressure vessels are used to store the gaseous agent to be screened. The 

discharge rate and duration are controlled by the initial agent pressure and an electronically 

actuated solenoid valve. Figure 2 is a pressure trace taken during a typical nitrogen discharge. 

The initial pressure is set to 960 kPa with an electronically controlled metering valve located 

between a standard high pressure nitrogen gas bottle and the stainless steel agent bottle. The 

computer acquires background data on the initial state for I scc, at which point thc electric 

solenoid valve is opened to allow nitrogen to enter thc wind tunnel. An electronic timer closes 

the valve after the desired interval. Pressure and temperature in the agent bottle are meusurcd at 

a frequency of 1000 Hz during the discharge process. The piezoelectric pressure transducer is 

able to follow the chanse, but the thermocouple is too slow. To determine the instantaneous 

mass discharge (dmidt in Figure 2). the nitrogen is assumed to be an ideal gas with thc expansion 

inside the bottle occurring iscntropically. The measured temperature adjusts much niorc slowly 

than the theoretical value (T:,,! in Figurc 2) due to the thermal inertia of the thermocouple. 

Three observations can be made from the shape of the discharge curve: (i) the discharge data iirc 

much noisier than the pressure data, because they rely on the gradient of pressure; (ii) the measured interval (about 180 msec) is longer than the IS0 msec interval set in the electronic timer, 

due to the inertia of the solenoid valve; and (iii) the discharge rate at the start of the process is 

markedly highcr than the average rate. 

Powders with physical properties similar to sodium bicarbonate can be injected into the tunnel by 

pressurizing thc vessel with nitrogcn or air and entraining a measured amount of the powder 

placed in a tee at the entriincc to the injection port, as was done previously in the turbulcnt spray 

burner [6]. The TARPF facility is designed to handle new propellant formulations for SPGG 

mass may need special accommodations. 

ints in quantities of about I g. Solid propellant gas generators of considerably higher 

RESULTS AND DISCUSSION 

The TARPF facility was operated over a range of propane and air tlows to examine qualitatively 

the behavior of the flame and to determinc conditions which lead to blow out. Blow-out can be 

achieved either by increasing the air flow or decreasing the propane flow. At low air velocities, ii 

fluctuating laminar flame is anchored on the top edge of the baffle or step and extends well 

downstream of the porous plate. The flame is orangc throughout and produces soot that quickly 

coats the side wall window. As the velocity increases, the flame becomes turbulent and less 

luminous, and the soot deposition ceases. Upon approach to blow-out, the orange color 

H:ilon Oplions Tcchnici Working Conlcrence 21-29 April I9W 107 
1000 

900 

m 800 

a 

Y 

700 v) 

v) 

? 

a 600 

500 

400 

\= 1 liter vessel, N, 300 1 50 

40 

250 1 lo P 

240 A0 -100 0 100 200 300 400 500 

Time, ms 

Figure 2. Measured pressure, temperature, and discharge rate of nitrogen from storage vessel. 

(Dotted line is theoretical agent temperature assuming adiabatic expansion.) 

disappears and the visible blue flame shrinks in length to a tight eddy at the base of the obstacle. 

The fuel injected at the downstream portion of the burner does not fully react near blow-out 

because it is mixed with air beyond its flammability limit. 

An average air velocity of 17 m/sec. found by dividing the volumetric flow (corrected to 101 kPa 

and 20 "C) by the duct inlet area (92 by 92 mm), is sufficient to blow out the flame stabilized on 

the 25 mm baffle if the propane flow (corrected to standard conditions) is less than 47 mL/sec. 

(This corresponds to a wall blowing velocity of 2.7 mm/sec). An average air velocity of 8 m/sec 

will extinguish a flame when the propane flow is 20 mL/sec, and less than 4 m/sec of air will 

blow out the flame for propane flows below 12 mL/sec. 

The amount of a suppressant necessary to extinguish a baffle stabilized tire in the TARPF 

depends upon the fuel and air flows chosen to challenge the suppressant. Figures 3 and 4 show 

how the amount of nitrogen necessary to extinguish the 25 mm baffle-stabilized flame varies 

with the flow of air and fuel. (The filled circles in the figures indicate extinction and the crosses 

represent no extinction.) When the air speed is less than 5 m/sec and the fuel flow is fixed at 

45 mL/sec, decreasing the speed (Figure 3) reduces the amount of nitrogen necessary to extinguish the flame. No flame extinction occurred between 5 and IS m/sec because the amount of 

nitrogen necessary exceeds the maximum amount contained in the storage vessel. Above 

16 m/sec, the strain on the flame is sufficient at times to extinguish the flame without the need 

for any nitrogen. (The dashed lines are included in the figure to assist the eye in identifying the 

extinction boundaries.) The propane flow does not have much affect on the amount of nitrogen 

needed to extinguish the flame if the injection interval and air flow are fixed (Figure 4). There is 

108 Halon Options Technical Working Confercncc 27-29 April I999 

~ ~ ~ 
12 

10 

r8 

2 

z6 .... 

0 

a, 

m 

r 

m 

u) 

54 

2 

0 

Figure 3. Impact of air speed on extinction of 25 mm baffle-stabilized tlame; propane tlow is 

45 mL/sec. nitrogen injection time is 3 I2 msec: circles imply extinction, crosses 

imply no extinction. 

Extinction Extinction 

+ + + +e. 

+ 

c"f+ + 

#+ 

- No Extinction - 

-- -- , , 

Extinction 

6 t 

5 + c 

m 

m 

z 

f;. 24 

= 

3 E No Extinction 1 m s2i 1 I 

0"""""'""' 

20 40 60 80 100 120 

Propane Flow, rnUs 

Figure 4. Impact of propane tlow on NZ required for suppression of 25 mm baffle-stabilized 

flame; air flow is 3.88 m/sec, injection time is I85 msec: circles imply extinction, 

crosses imply no extinction. 
a lower limit for the propane (<I2 mL/sec) that leads to extinction due to heat loss to the burner, 

even with no nitrogen dilution. The upper limit of propane (120 mL/sec) is dictated by the 

maximum safe operating temperature of the burner; however, since the mass of nitrogen needed 

to suppress the flame does not appear to increase, there is no need to operate the burner at higher 

fuel flows. (Note: The dip in mass required for propane flows around 75 mL/sec is attributed to 

the low number of experiments conducted in this region.) 

The relationship between the total mass of nitrogen required for suppression and the injection 

interval is plotted in Figure 5 for a 3.88 m/sec air flow, 45 mL/sec propane flow flame stabilized 

on a 25 mm baffle. The open symbols are experiments that did not extinguish the flame: the 

closed symbols are experiments that led to extinction. (The total number of experiments conducted exceeds by a factor of 10 the number of data points plotted in this and the following 

curves: for clarity, only those conditions close to the extinction boundary are included.) As the 

interval increases from 100 to 500 msec, the minimum mass required increases over three-fold. 

The rate of mass addition (calculated by dividing the total mass by the estimated injection 

interval) decreases with increasing injection interval, as shown in the right-hand figure. 

The effect of adding a ramp in front of the baffle to form a backward-facing step is examined in 

Figure 6. The data plotted with squares were taken at the same air flow (Figure 5): however, 

with a higher propane flow, 85 mL/sec. The addition of the ramp and increase in propane flow 

do not have much influence on the mass of nitrogen required for suppression (compare squares 

in Figure 6 to data in Figure 5). For both the baffle and backward step, just under 6 g of N2 are 

required when the injection interval is 200 msec. The data plotted as circles in Figure 6 were 

taken with the nominal air speed reduced to I .S m/sec and the propane flow reduced a proportionate amount to 33 mL/sec. Less than 4 g of N2 are needed to extinguish this flame if injected 

over a 200 msec interval. The differences in rates of mass addition to suppress the high flow 

(squares) and low flow (circles) flames can also be seen at the right (Figure 6). The low flow 

condition corresponds to what Takahashi et al. [SI describe as Regime I suppression (rim-stabilized flame), and the high flow is transitional between Regimes I and I1 (intermittent turbulent 

flame). 

Figures 7 and 8 show what happens to the required nitrogen mass and addition rate if the baffle 

height is decreased to 10 mm or increased to 55 mm (blockage from 11 to 60%). The symbols 

have the same meaning as in Figure 6: squares represent experiments conducted at the high air 

and propane flows, and circles represent experiments conducted at the lower flows. Open 

symbols indicate that the flame was not extinguished, and filled symbols indicate flame extinction. The short baffle produces a fire that is the easiest to extinguish, and the high baffle the 

most difficult in terms of the amount and rate of Nz addition. 

The effect of baffle height is not large if the injection interval is at least 150 msec, as can be seen 

more clearly in Figure 9. (Note that 6 mm have been added to the height of each obstacle to 

account for the distance between the floor of the tunnel and the recessed top surface of the 

burner.) The bottom curve delineates the minimum amount of nitrogen for suppression when the 

air flow is fixed at its high value and the agent injection interval is maintained at 175 msec. The 

open circles represent the largest mass of N2 that did not result in extinction for flames stabilized 

on the different sized baffles; the filled circles are the minimum mass of agent that successfully 

extinguished the flames. The diamonds are the results for the 25 mm baffle with the ramp in 

place (backward-facing step). 

1 10 Halon Options Technical Working Conference 27-29 April IWY 
lo 

8 

- 6 m 

VI 

m 

3 

4 

Extinction 

Q 

No Extinction 0 

0 

50 

in Extinction . -40 

e 0 

TI 

.- 

.

- - 

30 2 

VI 

VI 

/ 

0 

2 * e $0 

No Extinction / * ' 205 

m 

m 

I /- lIO OC 

loo 200 300 400 500 100 200 300 400 500 

lniection Time, ms Injection Time, ms 

Figurc 5. Mass and ratc of nitrogen addition required to extinguish 3.88 m/sec air flow. 4.5 mL/ 

sec propane tlame: filled diamonds. extinction: open diamonds. no extinction. 

cn 

vi 

VI 

2 

Injection Time, rns lniection Time, rns 

Figure 6. Mass and rate of nitroZen addition required to extinguish high flow (squares) and 

low flow (circles) aidpropane flames: filled symbols. extinction: open symbols, no 

extinction. 

Halon Options Tcchnicil Working Confcrence 21-2') April lW9 I 1 I 
Figure 7. Mass and rate of nitrogen addition required to extinguish high flow (squares) and 

low flow (circles) air/propane flames: filled symbols, extinction: open symbols, no 

extinction. 

u 

rn 

n 

I 

3 $0 

F! 

10 50 

m 

8 

6 rn 

mi 

m 

2 

4 

2 

C 

Figure 8. Mass and rate of nitrogen addition required to extinguish high flow (squares) and 

low flow (circles) air/propane flames: filled symbols, extinction; open symbols, no 

extinction. 

1 12 Halon Options Technical Working Conference 27-29 April IYYY 
The rate of mass addition is plotted in the upper curve (the triangles are the backward-lacing step 

and squiircs are the baffles). The data are plotted two ways: the higher value is the rate of nitrogen addition computed during the first SO msec that the solenoid valve is open (refer to the shapc 

of the dm/dt curve in Figure 2); the lower value is the average over the entire opcn interval measured from thc prcssurc trace. 

Hamins ct al. [4] found that for an injection duration, t, it is possible to relate p, thc mass Il.action 

of agent in the incoming stream at the extinction conditions, to Z, ii characteristic time that 

depends upon thc gcometry and velocity of the flow. For premixed flames stabilized by a bafflc 

in the middle of thc flow field, the riitc of agent cntrainment from the frec stream into the 

recirculation zone was suggested by Winterfeld [7] tn be proportional to the ratio of the baffle 

size to the free stream velocity. In the current work, 7 is defined as the distance from the fuel 

surface to the top of the obstacle (including the obstacle height, h, aid thc depth 01' recess, 8). 

divided by the average velocity over the obstacle while the agent is being discharged: 

Z = (h + &)/I (V';,i,+ V'N?)/[(L - h)Ll I (1) 

The velocity is written in terms ofthe volumc tlow of air and nitrogen, Vii,+ VIN?, divided by the 

area above the obstaclc, (L - h)L. where L is the length of the side of the square duct. Inserting 

into cquation (I) the range of values for tlow rate and baffle height examined in the current 

study, z is found to vary between about I msec and 10 msec. Figure 10 is a plot of agent mass 

fi-action versus the injection time normalized by Z. The data represent air velocities from 1 .S to 

3.88 m/sec. propane flows from 33 to 85 mL/scc. baffle heights bctween IO and 55 mm, and a 

backward step geometry. 

A two parameter mixing model 141 is used to correlate all of the experimental data in terms of p-. 

the minimum mass fraction of agent required for suppressing the flame at long injection 

intervals. and a, a parameter that relates the entrainment time to Z: namely. 

p=Pm / [ 1 -exp(-at/r)I. (1, 

!3-, can be found experimentally by flowing nitrogen continuously into the air stream at increasing rates until extinction occurs. If the air flow is low enough, one would cxpect Lo see a value 

for p- close to that measured in the cup burner for propane, which was found by Hamins et al. 

[6] to be 0.31. When the tlow of air is increased sufficiently, the flame becomes strained to the 

point that no additional nitrogen is needed lor extinguishment (i.e., p-=O). For laminar diffusion 

flames strained at intermediate rates. Trees et al. [8] showed that the minimum extinction mass 

fraction of nitrogen in a counter-flow flame above a heptane pool drops from thc cup-burner 

valuc when the strain rate is 50 sec~' to about 0.10 for a strain rate of 400 sec~'. While the tlow 

in the recirculating region behind thc baffle is much more complicated than in the countcr-flow 

flame of Trees et al., the scale of the strain ratc in the TARPF can be estimated from the range of 

I/T to lie between 100 and 1000 sec-'. 

Takahashi et al. [SI used a similar approach to correlate thc critical mole fraction of Halon 1301 

required to suppress a methane flume behind baffles in a rectangular duct. For an air speed of 

7.1 m/sec, their measurements taken with bafflc heights of 32 and 64 mm collapsed to a single 

curve when plotted against an injection time normalized by the stcp height divided by the air 

velocity. They did not accnunt for the velocity increase due to the agent tlow, hut were still able 

to get good results because the fraction of Halon 1301 is much smaller when compared to the 

H;ilon Oplionr Tcchnical Working Conlerencc 27-29 April 1999 1 13 
, 

- 10 - 

. 

. rn . 

0 

- 

. 

"," ~. ",". . { 

- 8 

jV 

2 a,.... "' - 

8 0 ..,," 

- 1 ~ 

. 

- 

- 

00 . , ,. . : . 8 6 

ul 

u) 

03- 

*"" -.-. -,I, ".. ," . ",, - 

- 

- 

- 4 - 

. 

140 

(0 

30 

C 

0 

TI 

._ 

.- - 

2 

5 

20 u) 

u) 

- 

0 

al 

Figure IO. Unified extinguishment nitrogen mass fraction as function of nondimensional 

injection time. Open symbols, no extinction; filled symbols, extinction. 

1.0 , , 'I'"'"""''"~'""~'"~'~'' - . . 

- P = P,J ( 1- e-avf ) 

Po, = 0.32, a = 0.026 

- - - 0.8 - z = h (L-h) U(V,,, + VN2) - 

- 

4'00 - 

; 45 - 

- 0.6 - 

- 

- - - - - 

- - a- vm- -W - - *- 

0.2 - upward triangles - 25 mm step - 

- circles - 55 mm baffle - 

0.4 - .J- % mJL?"s 

m 

a, 

I 

m 

squares - 10 mm baffle 

downward triangles - 25 mm baffle 

- - - - 

. 

0.0 ~"~"'~~"~"~''~'"'"'"'~~'~'~ 

1 14 Halon Options Technical Working Conference 27-29 April I999 
nitrogen flows needed in thc present study. The value of p- with Halon 1301 was found to bc 

slightly less than the heptanc cup-burner valuc. The work donc by Hamins et al. [4] using HFCI25 and HFC-227ea suggests that p- may he greater than the cup-bumer valuc for low air flows 

and strain rates. This is consistent with the results of Dyer et al. 191 in their study using nitrogcn 

to suppress kerosene pool fires in air strcams at speeds below 0.2 m/sec. 

The dashed line in Figure 10 is equation (2) with p- set to 0.32 and CY. chosen. by inspcction, to 

be 0.026. While the data for any particular geometry and air flow may be better fit by selecting 

corresponding values for p- and a, the hulk of the data are well represented by the single curve. 

The run-to-run variation and uncertainty in the data may not warrant finer analysis, especially 

when one considei-s how ill-defined the flow and gcornetry are in an actual engine nacelle. 

SUMMARY AND CONCLUSIONS 

A transient application, recirculating pool fire (TARPF) facility has been built for screening the 

suppression effectiveness of Halon 1301 replacements. Initial characterization experiments werc 

conducted with nitrogen as the suppressant. Nominal air vclocities bctween I and 17 m/sec 

flowing over baffles that are 16 to 61 mm above the surface of a propane pool fire were examined. Two to 10 g of nitrogen injected over intervals between SO and 700 msec are required tn 

cxtinguish flames of up to 10 kW. Because the air is metered with ii sonic orifice, the injection 

of agcnt does not modulate the air flow. For moderate flows of air and fuel, the amount of nitrogcn for flame extinguishment is substantially and directly affected by the air velocity and the 

intcrval of injection. The height or the obstacle, whether it is a baffle or a backward facing step, 

and the propane blowing velocity have only a minor iniluencc on the mass of nitrogen needed for 

suppression. 

Halon 1301. additional gaseous afents. powders, and solid propcllant gas gcnerators will be 

examincd in the future. The impact of spraying JP-8 onto ii controlled liot surface during the 

suppression process also will he determincd. 

The ability to measurc the relative erfectiveness of :ilternative agents is key to the development 

or new fire supprcssion systems. The Next-Gcneration Program has the goal of idcntifying 

agents that are as effective as CFjBr in supprcssing fircs in spaces currently protected with halon. 

The physical and chemical properties, and thc manner of storage and release, of thcse next 

generation suppression systems may be quite unlike halon, hut their effectiveness must he 

benchmarkcd against CFjBr. The TARPF facility will provide the means to screen new concepts 

in the laboratory for applications in enginc nacelles and other spaccs involving baflle-stabilizcd 

pool fires with adjacent hot surfiiccs. 

ACKNOWLEDGMENTS 

This work has been sponsored by the Department of Defense Next-Generation Fire Suppression 

Technology Program. co-funded by the DoD Strategic Environmental Research and Development Program. Mr. Michael Selepak has been instrumental in developing the facility and taking 

the experimental data. Discussion with Anthony Hamins and Kevin McGrattan have been most 

helpful. Thc assistance of all is gratefully acknowledged. 
REFERENCES 

Hirst, R. and Sutton, D., Combust. Flame, 5, 319-330, 1961. 

Hirst, R., Farenden, P. J., and Simmons, R. F., Fire Technology 12, 266, 1976. 

Hirst, R., Farenden, P. J., and Simmons, R. F., Fire Technology 13, 59, 1977. 

Hamins, A., Cleary, T., Borthwick, P., Gorchov, N., McGrattan, K., Forney, G., 

Grosshandler, W., Presser, C., and Melton, L., “Suppression of Engine Nacelle Fires,” 

Chapter 9 in Fire Suppression Syst. Per:formance ($Alter. Agents in Aircraft Engin(, and 

Dry Bay Lab. Simulations, NIST SP 890: Vol. 11, Gann, R. G. (ed.), DOC, Washington, 

DC, Nov. 1995. 

Takahashi, F., Schmoll, W. J., and Belovich, V. M., “Suppression of Bluff-body Stabilized 

Diffusion Flames,” AIAA 98-3529.34th AIAA/ASME/SAE/ASEE Joint Propulsion 

Conference and Exhibit, Cleveland, July 1998. 

Hamins, A., Gmurczyk, G.. Grosshandler, W., Rehwoldt, R., Vasquez, I., Cleary, T., 

Presser, C., and Seshadri, K., “Flame Suppression Effectiveness,” Section 4 in EwzI. Alt 

In-flight Fire Sup.@ Full-scale Testing in Sim. Aircrafi Engine Nacelles and Dry Buys, 

NIST SP 861, Grosshandler, W., Gam, R., and Pitts, W. (eds.), DOC, Washington, DC, 

April 1994. 

Winterfeld, G., “On Processes of Turbulent Exchange Behind Flame Holders,” Tenth 

Symposium (International) on Combustion, The Combustion Institute, 1265, 1965. 

Trees, D., Seshadri, K., and Hamins, A. M., “Exp. Studies of Diffusion Flame Extinction 

with Halogenated and Inert Fire Suppressants,” in Halon Replacements - Technology and 

Science, A. Miziolek and W. Tsang (eds.), ACS Symposium Series 61 I, Am. Chem. SOC., 

1995. 

Dyer, J. H., Marjoram, M. J., and Simmons, R. F., Fire Technology 13, 126, 1977. 

1. 

2. 

3. 

4. 

5. 

6. 

7. 

8. 

9. 

1 16 Halon Options Technical Working Conference 27-29 April 1999