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Effect of CF3H and CF3Br on Laminar Diffusion Flames in Normal and Microgravity.


pdf icon Effect of CF3H and CF3Br on Laminar Diffusion Flames in Normal and Microgravity. (484 K)
VanDerWege, B. A.; Bush, M. T.; Hochgreb, S.; Linteris, G. T.

Combustion Institute/Eastern States Section. Chemical and Physical Processes in Combustion. Proceedings. Fall Technical Meeting, 1995. October 16-18, 1995, Worcester, MA, 443-446 pp, 1995.

Sponsor:

National Aeronautics and Space Administration, Lewis Research Center, Cleveland, OH

Keywords:

combustion; laminar flames; diffusion flames; gravity; bromotrifluoromethane; experiments; microgravity

Abstract:

Due to the ban on production of bromotrifluoromethane (CF3Br) because of its high ozone destruction potential, there has been recent interest in finding a replacement for it for fire extinguishing applications. While a variety of potential replacements are being considered, halogenated hydrocarbons may be a viable alternative for some applications. Consequently, an improved understanding of their action in flames will aid in their effective use. In addition, CF3Br is used as a fire suppressant on the space shuttle, and its action in microgravity has not been tested in diffusion flames. The present study investigates the effects of CF3Br and trifluoromethane (CF3H), the simplest compound representative of the fluorocarbons, in laminar diffusion flames. The primary experiments are laminar gas-jet diffusion flames burning in a quiescent environment containing the inhibitor in normal and microgravity. Experiments were conducted with CF3Br mole fractions in the oxidizer gas of 0.5% to 3%, CF3H mole fractions of 4% to 12%, oxygen mole fractions from 18% to 30%, and ambient pressures of 101 kPa and 25 kPa. Additional opposed-jet counterflow diffusion flame experiments were used to investigate flame structures observed in the microgravity flames.