BEM modeling of large silencers with reflective symmetry

Large silencers used in power generation often have certain reflective symmetry. To model large silencers with efficiency, it is desirable to reduce the model size as much as possible. In this paper, the impedance-to-scattering matrix method is used along with the boundary element method (BEM) to model only a quarter of the silencer. However, the number of modes is significantly reduced, and the modes used in the impedance-to-scattering matrix method must be carefully selected since the BEM mesh does not contain all the required information to support the full modal expansion. A test case is used to demonstrate the revised formulation.