Analysis of the Wright Patterson Full-Scale Engine Nacelle Fire Suppression Experiments.
Analysis of the Wright Patterson Full-Scale Engine
Nacelle Fire Suppression Experiments.
Hamins, A.; Cleary, T. G.; Yang, J. C.
NISTIR 6193; 121 p. November 1997.
Available from: National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
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aircraft safety; nacelle fires; blowout velocity; flame
extinguishment; flammability limits; halogenated
compounds; ignition; sprays; fire suppression
An analysis is presented on the full-scale suppression
experiments conducted during 1996 and 1997 in the F-22
engine nacelle fire simulator at Wright Patterson Air
Force Base. Experiments investigated the relative
effectiveness of halogenated agents and solid propellant
gas generators (SPGG) in suppressing a series of spray
fires with and without a fuel re-ignition source.
Several agents were tested including halon 1301,
HFC-125, and two basic types of SPGG which included
those that produced inert gases in conjunction with a
fine solid particulate (some which contained K2CO3), and
those that produced inert gases only. The SPGG devices
were more or less effective depending on the agent
composition and the agent delivery rate. The SPGG
effluent which contained a significant percentage of
K2CO3 particulate was particularly effective for
re-ignition protection, a scenario which dominates agent
mass requirements for the compressed halogenated
liquids. A number of measurements were made during the
suppression tests. Measurements included gas
temperatures, the re-ignition source temperature, the
cold-flow agent concentrations (no fuel spray or fire
present), and velocity measurements. This information
was with the different suppressant types. A simple
model for SPGG delivery was developed. Assuming plug
type flow, the transient average agent concentrations
were calculated in the nacelle and compared to
measurements. The results give reasonable agreement.