Numerical mode-matching approach for acoustic attenuation prediction of straight-through perforated tube silencer

A numerical mode-matching(NMM) approach is developed to predict the acoustic attenuation performance of straight-through perforated tube reactive silencers with arbitrary cross-sectional shape.The 2-D finite element method (FEM) is employed to calculate the transversal eigenvalves and eigenvectors,and the mode-matching technique is used to determine the modal amplitudes,and then the acoustic properties of the silencer may be obtained.The transmission loss results from NMM approach,3-D FEM and experiment agree well with each other for the circular and elliptical straight-through perforated tube silencers,which demonstrates that the present numerical mode-matching approach may be applied to predict the acoustic attenuation performance of straight-through perforated tube silencers accurately.The study shows that the perforated tube offset affects the acoustic attenuation performance in the middle to higher frequency range,and the concentric silencers exhibit better acoustic attenuation performance than the non-coaxial configurations.