EXPERIMENTAL-STUDY OF ACOUSTIC VELOCITY EFFECTS ON SIMULATED SOLID-FUEL PYROLYSIS

An experimental study of the effect of acoustic velocity oscillations on solid fuel pyrolysis, modeled using dry ice sublimation, was perfor med. Use of dry ice as a solid fuel simulant allows the fluid mechanic s of the problem to be separated from the combustion process, The expe rimental facility was designed to model solid waste pyrolysis in an ac oustically excited incinerator. Dry ice was placed in a rectangular ch amber in which resonant acoustic oscillations could be driven. A mean how of air entered from one end of the chamber, and exhaust was remove d from the opposite end. Flow visualization indicated that the mass tr ansport near the dry ice surface was greatly increased when velocity o scillations were present. When the dry ice was positioned at an acoust ic velocity antinode of a 160-dB standing oscillation, the sublimation rate was nearly 60% greater than without oscillation. For the conditi ons studied, the effects of velocity oscillations at a constant amplit ude became greater as the mean velocity was increased, Comparison of t he sublimation rates measured with dry ice located at acoustic velocit y and pressure antinodes shows that, at constant amplitude, acoustic v elocity oscillations have a much greater effect on the sublimation rat e than pressure oscillations.