分层多孔材料吸声结构的性能分析

Acoustic analysis for a sound-absorbing structure with multi-layered porous material

利用声波在分层介质中的传播方程,给出了由不同种吸声材料复合而成的多层吸声结构吸声系数的递推计算公式。继而以由多孔吸声材料复合而成的双层吸声结构为基础,通过数值仿真,深入分析了内外层材料的厚度、孔隙率、和微孔半径变化对吸声系数的影响。以导出的递推计算公式为基础,通过仿真实验研究了分层吸声结构的参数优化设计。结果表明:由多孔材料复合而成的分层吸声结构具有良好的吸声效果,通过合理配置各层材料结构参数,可以在较宽的频段上达到较为满意的吸声效果,从而为相应产品的开发提供了理论依据。

By using the transmission equation of acoustic wave in a layered media, the recursive formula of absorption coefficient of a multi-layered structure was derived. Then, for a double-layer structure made of porous sound- absorbing material, the effect of acoustic parameters including thickness, porosity and pore radius of each layer on the absorption coefficient was analyzed with numerical simulation. Based on the recursive formula, parameter optimization of a multi-layered sound-absorbing structure was investigated. It was shown that the multi-layered sound-absorbing structure made of porous sound-absorbing material has good sound absorption capacity and can reach satisfactory sound absorption level in a wider frequency range. The results provided a theoretical support for product design.