SOUND TRANSMISSION IN MUFFLERS WITH MULTIPLE PERFORATED CO-AXIAL PIPES

Although there exists ample literature on the analysis of mufflers with parallel multiple perforated pipes, there is a surprising void of papers on acoustical modelling of mufflers employing multiple co-axial pipes. In the present paper, the distributed parameter method is extended for the analysis of mufflers employing multiple co-axial pipes. The theory is presented in a generality encompassing any number of co-axial perforated pipes. Implementation of the theory is shown on a resonator with two co-axial perforated pipes. Experimental validation of the predictions is provided for the case of zero mean flow.