Boundary element analysis of a straight-through hybrid silencer

Combining the acoustic attenuation behaviors of reactive and dissipative silencers, a straight-through hybrid silencer consisting of a concentric folded resonator and a dissipative chamber is presented and the substructure boundary element approach is employed to predict and analyze the acoustic attenuation characteristics in absence of mean flow. The BEM predictions demonstrated the acoustic attenuation effectiveness of the hybrid silencer over a wide frequency range. The effects of internal geometry, porosity of perforation and flow-resistivity of sound-absorbing material on acoustic attenuation performance of the hybrid silencer are investigated in detail.