Flow of Alternative Agents in Piping.
Flow of Alternative Agents in Piping.
(545 K)
Cleary, T. G.; Grosshandler, W. L.; Yang, J. C.
Halon Options Technical Working Conference.
Proceedings. HOTWC 1994. May 3-5, 1994, Albuquerque,
NM, 105-115 pp, 1994.
Keywords:
halons; pipes; nacelle fires; fire protection; aircraft
engines; fire suppression; fire extinguishing agents;
halon alternatives
Abstract:
As part of the USAF, Army, Navy and FAA sponsored halon
replacement project, the pipe flow characteristics of
selected alternative agents for engine nacelle fire
protection are being studied. Due to the remote
location of the agent storage bottle, piping is required
to transport the agent to various locations in an engine
nacelle. The pipe flow from an agent bottle is
characterized as a transient, two-phase flow. Since the
selected alternative agents have thermo-physical
properties different from halon 1301, the flow
characteristics will be different, which may require
system design changes. An experimental apparatus to
study the flow characteristics of the alternative agents
was designed and is described. A key feature of the
experimental set-up is the ability to provide a constant
heat in the simulated storage bottle. This will allow
quasi-steady state pressure drop data to be gathered.
It may then be possible to use the quasi-steady data to
estimate the transient case. The pipe flow
characteristics for different initial vessel
temperatures and pressures, and pipe configurations will
be examined. Preliminary results on the flow
characteristics of HFC-227ea and halon 1301 are
presented.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899