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Pipe Flow Characteristics of Alternative Agents for Engine Nacelle Fire Protection.


pdf icon Pipe Flow Characteristics of Alternative Agents for Engine Nacelle Fire Protection. (883 K)
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.

Keywords:

fire suppression; flow measurement; halon 1301; pressure drop; halon alternatives

Abstract:

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.