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Pipe Flow Characteristics of Alternative Agents for Engine Nacelle Fire Protection



Thomas G. Cleary, Jiann C. Yang, William L. Grosshandler, Michelle King, C I. Boyer


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 candidates: HFC-227ea, HFC-125 and CF31. The flow regime in suppression system piping is characteristically a two-phase, two-component gashquid 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.


Cleary, T. , Yang, J. , Grosshandler, W. , King, M. and Boyer, C. (1995), Pipe Flow Characteristics of Alternative Agents for Engine Nacelle Fire Protection, Other, National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed June 18, 2024)


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Created January 1, 1995, Updated February 19, 2017