BEM analysis of large three-port silencers with FEM-AML validation

Three-port silencers are frequently used in industry to merge two inlets into one common outlet stream or one inlet into two outlets. The current approaches to analyze the three-port silencers, including the BEM impedance matrix and the superposition method, are limited to small inlet and small outlet cross sections where the plane-wave assumption is still valid. In this paper, the recently developed BEM impedance-toscattering matrix method for large silencer analysis is extended to large three-port silencers so that the higherorder propagating modes at the inlets and outlets can be considered in the transmission loss (TL) calculation. The BEM TL solution is validated by an equivalent IL solution using the Automatically Matched Layer (AML) in the FEM for the one-inlet/two-outlet configuration.