Determination of noise level of a gas-fired pulse combustor

Abstract

Experimental determination of noise level of a Helmholtz type gas-fired pulse combustor is presented. During the tests, the tail pipe length was varied from 1.9 m to 1.3 m by 10 cm intervals. Noise level measurements were obtained from the outlet (exhaust side ) and inlet (air flapper side) at a length of 1 m from both sides by means of a noise level meter. As the length of the tail pipe was decreased, the noise level increased. At the measurements performed at the outlet, the peak value of equivalent continuous noise level, LEQ was 96.6 dB as the tailpipe length of the fundamental frequency were 1.3 m and 63 Hz, respectively. Similar kinds of measurements were carried out at the inlet, but the LEQ value was stronger at the outlet than the one at the inlet. It was also investigated that the effect of the type of gaseous fuel on the acoustic efficiency of the pulse combustor can be neglected when the results of the acoustic efficiencies were compared to those in the literature.