静压下球形空腔吸声覆盖层的建模与性能分析

基于声波垂直入射下的二维理论，利用COMSOL软件建立球形空腔吸声覆盖层单元模型，得到了在空腔受压变形基础上直接进行声学性能计算的耦合模型，避免了以往根据变形量重新建模带来的误差，并与静压下穿孔率的理论公式进行对比，验证了模型的有效性；利用所建模型分析了静压下球形空腔的吸声性能，并比较了内部气压对空腔变形和吸声系数的影响。结果表明：随着静压的增大，峰值上移频带展宽，更显著的是吸声效果总体变差；内部气压使得空腔变形量减少、低频吸声效果有所提高。

Model and absorption performance of anechoic coating embedding sphere cavities

Based on the 2D theory of sound wave normally impinging on the absorption layer, the acoustic-solid interaction model of anechoic coating which contains sphere cavities was made by COMSOL software and the model can calculate absorption coefficient directly instead of remodeling according to the volume of deformation under hydrostatic pressure. Perforation rate was compared between COMSOL and analytical solution in order to prove the validity of the model. The absorption property and influence of the internal air pressure were analysed based on the interaction model. The results indicate that with increasing of hy-drostatic pressure the peak frequency is towards to the high frequency and becomes wider, the more differ-ence is that effect of sound absorption becomes worse; internal air pressure makes the deformation of the cavity decrease and absorption coefficient in low frequency increase.