A Numerical Analysis for Perforated Muffler Components with Mean Flow

A boundary element approach for analyzing the perforated muffler components with mean flow is developed. Most of the research on perforated mufflers is based on the assumption of plane wave propagation. In the present method, the effects of mean flow, including the convection effect in governing equation and the change of acoustic impedance of perforated tube, are considered and the influences of higher order modes are also included. The acoustic performance prediction is performed on the perforated intruding tube mufflers and also on the plug muffler with and without mean flow. Comparisons of the influences of various porosity, the mean flow velocities, the tube thickness and the hole diameters are investigated. However, the results need to be verified by further experimental measurement.