Analysis and Experimental Study of the Mean Flow Effect on the Sound Transmission Through a Cylindrical Shell of an Automobile Muffler

Sound transmission through the sidewall of an automotive muffler has been studied theoretically and experimentally. Three wall structures: a single shell, double shell and porous-cored shell constructions are considered. Transmission losses through the sidewalls were measured using the two microphone method. Experimental results are compared to one another, and to the corresponding theoretical analysis results, which shows that the mean flow effect is not a significant factor in designing the muffler sidewall.