EXPERIMENTAL INVESTIGATION OF ACOUSTIC PROPERTIES OF

Transmission loss of exhaust mufflers with perforated pipes is experimentally investigated. The main work of this paper is focused on the one dimensional plane wave propagation; additionally, higher order mode effects are discussed. Two types of cross flow mufflers, a plug flow muffler and an eccentric muffler, are investigated with and without the presence of mean flow, using the two source measurement method. A sensitivity comparison on the segmentation method simulation model, with different flow distribution assumptions, is discussed. The results present an investigation of the geometrical, physical and operational factors on the acoustic behaviour of such cross mufflers. The predictive modelling includes one dimensional CFD and three dimensional FEM. Comparisons between measured and predicted performance of three different mufflers are presented as a summary of nine different tested cases