PARTICLE GENERATION AND EVOLUTION IN SILANE/ACETYLENE FLAMES IN MICROGRAVITY


Abstract

The objective of this new experimental program is to advance the understanding of the formation of particles from gas phase combustion processes. The work will utilize the unique SiH4 /C2H2 combustion system which generates particulate products ranging from high purity, white SiC to carbonaceous soot depending on equivalence ratio (Ref 1). A key goal of this work is to identify gas phase or particle formation processes that provide the enthalpy release necessary to drive the combustion wave, and to locate the parts of the particle formation process that determine SiC stoichiometry and crystallinity. In a real sense, those SiH4 /C2H2 flames act like "highly sooty" hydrocarbon flames, but with simpler chemistry. This simplification is expected to allow them to be used as surrogates to advance understanding of soot formation in such rich hydrocarbon flames. It is also expected that this improved understanding of SiC particle generation and evolution in these self-sustaining flames will advance the commercial potential of the flame process for the generation of high purity SiC powders.


Keil, D.G., Particle Generation and Evolution in Silane/Acetylene Flames in Microgravity, Sixth International Microgravity Combustion Workshop, NASA Glenn Research Center, Cleveland,OH, CP-2001-210826, pp. 429-432, 2001.