Pipe Flow Characteristics of Alternative Agents for Engine Nacelle Fire Protection.
Pipe Flow Characteristics of Alternative Agents for
Engine Nacelle Fire Protection.
Cleary, T. G.; Yang, J. C.; King, M. D.; Boyer, C. I.;
Grosshandler, W. L.
Halon Options Technical Working Conference.
Proceedings. HOTWC 1995. May 9-11, 1995, Albuquerque,
NM, 171-182 pp, 1995.
fire suppression; flow measurement; halon 1301; pressure
drop; halon alternatives
As part of the U.S. Air Force, Army, Navy and FAA Halon
Replacement Project at NIST, the pipe flow
characteristics were investigated for three engine
nacelle alternative candidate: HFC-227ea, HFC-125 and
CF3I. The flow regime in suppression system piping is
characteristically a two-phase, two-component gas/liquid
system. An apparatus was built to study the pressure
drop and flow time of the alternative agents and of
halon 1301 as a reference for different storage
conditions and piping configurations. The pressure
drops and flow times of the alternative agents and halon
1301 show similar trends suggesting that for actual
systems, design approaches similar to those used for
halon 1301 systems are possible for the alternatives.
High speed movies confirmed the two-phase nature of the
flow. A computer model that simulates steady-state and
transient discharge of nitrogen-pressurized agent from a
storage bottle through piping was developed. The model
may prove useful in preliminary design of engine nacelle
systems employing an alternative agent.