Suppression of Engine Nacelle Fires.
Suppression of Engine Nacelle Fires.
(9464 K)
Hamins, A.; Cleary, T. G.; Borthwick, P.; Gorchkov, N.
N.; McGrattan, K. B.; Forney, G. P.; Grosshandler, W.
L.; Presser, C.; Melton, L.
NIST SP 890; Volume 2; Section 9; November 1995.
Fire Suppression System Performance of Alternative
Agents in Aircraft Engine and Dry Bay Laboratory
Simulations. Volume 2, Gann, R. G., Editor(s), 1-199
pp, 1995.
Available from:
National Technical Information Service
(NTIS), Technology Administration, U.S. Department of
Commerce, Springfield, VA 22161.
Telephone:
1-800-553-6847 or 703-605-6000;
Fax: 703-605-6900.
Website: http://www.ntis.gov
Order number: PB96-117783
Keywords:
fire suppression; aircraft engines; nacelle fires;
simulation; halon 1301; halon alternatives; aircraft
safety; blowout velocity; flame extinguishment;
flammability limits; halogenated compounds; ignition;
pool fires; sprays; wind tunnels
Abstract:
A series of experimental measurements were conducted and
simple models were developed in an effort to provide an
improved understanding of the influence of various
parameters on the processes controlling flame stability
in engine nacelle applications. The knowledge gained is
compiled into usable tools which may assist suppression
system designers determine the mass and rate of agent
injection required for engine nacelle fire suppression.
The Section is broken into several subsections. In
Section 9.2, a description of the range of parameters
which characterize engine nacelles is provided. The
historical development of current halon 1301 fire
protection systems is described. In Section 9.3, the
results of four distinct experiments are discussed.
First, the suppression effectiveness of candidate
replacement agents (CF3I, C2HF5, and C3HF7) are tested
on a turbulent jet spray flame. Second, suppression of a
baffle stabilized pool fire is described. Third,
measurements on the impact of the replacement agents on
the ignition temperature of fuel/air/agent mixtures is
discussed. Finally, measurements determining the
flammability limits of propane/air/C2HF5 mixtures are
discussed. The importance of agent entrainment into the
recirculation/combustion zone of obstacle stabilized
flames is emphasized. In Section 9.4, computational
modeling of gaseous agent injection into a mock engine
nacelle is described. The calculations are compared to
measurements conducted in a wind tunnel. In Section
9.5, a simple algebraic model is developed which gives
guidance on agent concentration requirements for flame
suppression in generic nacelle configurations. Key
findings and recommendations are compiled in Section
9.6. References are listed in Section 9.8.
