- Author
-
Hamins, A.
|
Cleary, T. G.
|
Yang, J. C.
- Title
- Analysis of the Wright Patterson Full-Scale Engine Nacelle Fire Suppression Experiments.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Report
-
NISTIR 6193,
November 1997,
121 p.
- Keywords
-
aircraft safety
|
nacelle fires
|
blowout velocity
|
flame extinguishment
|
flammability limits
|
halogenated compounds
|
ignition
|
sprays
|
fire suppression
- Identifiers
- Solid Propellant Gas Generators (SPGG)
- Abstract
- 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.