The effect of convection of fluid on the acoustic performance of perforated mufflers

Many practical mufflers with complex geometry have large variations in the flow filed. In addition, the flow-reversing pipes and perforated elements in the muffler further complicate the flow patterns. Therefore, the effect of convection of fluid needs be considered in acoustic computations of mufflers. The present study employs the computational fluid dynamics (CFD) software FLUENT to capture the inner flow field, and then the fluid velocity data are imported to the acoustic finite element (FE) model to determine the acoustic attenuation performance of mufflers. The numerical results are compared with previously published experimental measurements demonstrating the applicability of present method. Furthermore, the effect of convection of flow on acoustic attenuation performance of the mufflers is analyzed in detail. It is concluded that the convection of fluid may affect remarkably the transmission loss of perforated mufflers.