Transmission loss prediction on a single-inlet/double-outlet cylindrical expansion-chamber muffler by using the modal meshing approach

This work formulates the acoustical performance prediction on a single-inlet/double-outlet cylindrical expansion-chamber muffler. Expressions for the transmission loss (TL) of the muffler are formulated by using the modal meshing approach and the plane wave theory, respectively. The parametric influence upon the values of TL for this kind of muffler is numerically analyzed for various cases of length-diameter ratio, and the computed results of TL are compared to present the higher order mode effects. The results by the modal meshing approach are also compared with the finite element method to verify its accuracy.