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Selection of a Simulant of CF3Br for Use in Engine Nacelle Certification Tests.


pdf icon Selection of a Simulant of CF3Br for Use in Engine Nacelle Certification Tests. (1154 K)
Womeldorf, C. A.; Mitchell, M. D.; Grosshandler, W. L.

Halon Options Technical Working Conference. Proceedings. HOTWC 1995. May 9-11, 1995, Albuquerque, NM, 197-210 pp, 1995.

Sponsor:

Naval Air Warfare Center, Lakehurst, NY

Keywords:

aircraft certification; halon 1301; pentafluoroethane; sulfur hexafluoride; halon simulants; nacelle fires; fire suppression; aircraft engines; boiling point; critical temperature; halon alternatives

Abstract:

This paper describes the selection of a simulant of CF3Br for the purpose of certification testing engine nacelles fire suppression systems. In order to illustrate the storage, delivery, and distribution requirements of CF3Br, relevant characteristics of engine nacelle fire suppression systems and certification tests are briefly summarized. An initial screening of over 1300 chemicals based upon the boiling point, critical temperature, and molecular weight of CF3Br is described, and the nine potential candidate simulants that were found are listed. Three final candidates (SF6, C2HG5, and CHCIF2) were selected for experimental testing based upon their vapor pressures, Jakob numbers, and the requirements of this application: ozone depletion potential, flammability, corrosiveness, toxicity, stability, and atmospheric lifetime. To evaluate the hydraulic properties of the simulants compared to CF3Br, pressure traces of discharges through a piping system are compared. A second comparison using high speed movies of the spray plumes at the end of the piping system is described. Results from these comparisons of the three candidate simulants with CF3Br are presented.