直通穿孔管消声器声学特性预测的数值模态匹配法

将数值模态匹配法应用于计算横截面为任意形状的直通穿孔管抗性消声器的声学特性。应用二维有限元法计算横截面的本征值和本征向量,应用模态匹配技术求解模态幅值系数,进而得到所需的声学量。对于圆形和椭圆形直通穿孔管消声器的传递损失,数值模态匹配法计算结果与三维有限元计算结果和相应的实验测量结果吻合良好,表明数值模态匹配法能够精确计算直通穿孔管消声器的声学特性。计算结果表明,穿孔管的偏移影响消声器在中高频段的消声特性,同轴结构消声器的消声性能好于非同轴结构。 

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.