Acoustical Analysis of Circular Straight Mufflers with Bias Inlet/outlet Ducts

In order to overcome the drawback of the accuracy for the Plane wave theory in the muffler’s acoustical calculation in the region of higher frequencies, we use a theoretical analysis of eigen function in conjunction with a four-pole system matrix to evaluate the TL of a circular straight muffler with bias inlet/outlet duct. With this method, the acoustical calculation can be speeded up comparing to traditional simulation of FEM and BEM method. Consequently, results reveal that the bias effect will tremendously influence the acoustical performance of the muffler.