A Valveless Pulse Combustor With Wide Operation Range and Low Noise Level

Abstract

The possibility of a valveless pulse combustor with wide range and low noise level was experimentally examined by introducing two practical approaches simultaneously: one is the rich mixture supply outside the flammability limit, instead of the ordinary fuel supply without any primary air; the other is forced secondary air ventilation. An overall evaluation of pulsation limits was also made in terms of the volumetric efficiency of the pulse combustor. Fuel used was a commercial grade gaseous propane. The results showed that, under a constant total of equivalence ratios of 0.9, a large turn-down ratio of 9.4–11.5 and a high combustion intensity of 55–67MW/m3 could be obtained by setting the rich mixture equivalence ratio equal to 3.0. Also, the proposed valveless pulse combustor could operate more silently than the flapper-valved one by 3-8dB (A), being indicative of noise radiation due to valve flapping.