A.K. Kulkarni, J. Hwang

A comprehensive mathematical model is presented for understanding tHe characteristics of a burning vertical wall immersed in a quiescent ambient atmosphere having a nonuniform vertical distribution of temperature and oxidizer mass fraction. Such a stratified atmosphere occurs, for example, in the interior of a room or aircraft cabin on fire. A set of partial differential equations and suitable boundary conditions: describing a laminar flow of exothermically reacting species, is solved using the Kelle Box finite difference scheme. Results of burning rate and flow parameters (such as the maximum vertical velocity, flame position, etc.) are presented for many different cases of stratified atmosphere. A comparison of these results with the results for the nonstratified atmosphere shows that the predicated burning rate for a thermally stratified case behaves like a linear combination of results for the corresponding nonstratified cases; however, this does not hold for compositionwise stratified atmosphere. The stratification has a substantial nonlinear effect on the flow structure in the wall fire. Different possibilities for surface reradiation models are also discussed.

Eugene P. Klueg, Francis B. Howard

The National Transportation Safety Board (NTSB) data on 627 accidents, involving U.S. turbine-powered aircraft from 1964 through 1983 was reviewed to determine the potential effectiveness of antimisting kerosene (AMK) fuel in minimizing fire fatalities and damage.

Postcrash fires occurred in 91 accidents and sufficient data were available for 70 of these postcrash fire acidents to characteristize the potential effectiveness of AMK protection. Forty-three of the 70 accidents were considered to be impact-survivable. AMK protection could have been expected in 34 of these 43 impact-survivable accidents. The analysis also shows 346 of 348 known deaths due to fire in the 43 accidents could have been saved if AMK had been the fuel. If the 156 deaths due to unknown causes are appointed in the same ratio as the known cases, and additioanl 66 lives could have been saved.

Richard G. Hill, Lawrence T. Fitzgerald

A computer program was developed to correlate and statistically analyze laboratory and full-scale fire test data. The program and its usage is presented in this report. Also, the results of a roundrobin test program utilizing the Ohio State University Rate of Heat Release (OSU) test appartus are described. Data from the roundrobin was used to show the capabilities of the newly developed computer program. The results of the roundrobin indicated that reproducibility between laboratories had increase and that a further increase could be expected with greater standardization of equipment and procedures.

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

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.

L.A. Desmaris

Dry chemical fire extinguishing agents were studied in a simulated small scale aircraft engine nacelle environment to observe the ability of these agents to prevent re-ignition a known deficiency of the presently used gaseous agents. An injector was developed which effectively dispersed agent into the airstreams; a fuel spray behind a flameholder, ignited and sustained by a hot surface, was used as the test scenario. The agents were found to be effective in very small quantities (<30 grams) for initial suppression of the fire, but permanent extinguishment was found to be a function of test conditions. The agents tended to accumulate on test surfaces and cause some corrosion as the result of repeated applications but were easily cleaned from affected surfaces.