含空腔声学覆盖层等效参数理论与吸声机理研究

Equivalent Parameter Theory and Sound Absorption Mechanism of Acoustic Coating with Cavities

针对含水平周期圆柱空腔的声学覆盖层声吸收问题,在弹性波声传播理论的基础上,以准静态极限理论为前提,获取含空腔覆盖层均匀等效参数,进一步利用传递函数法得到吸声系数表达式。通过与有限元数值计算结果对比,验证了算法的正确性。重点从圆柱空腔单极子共振出发阐述覆盖层的声吸收机理,并从吸声曲线、覆盖层位移图等多角度展示主要参数对吸声性能的影响规律,可为低频高吸收声学覆盖层设计提供指导。

The problem of acoustic absorption of the acoustic coating with periodic horizontal cylindrical cavities is studied.Based on elastic wave propagation theory and quasi-static limit theory,the uniform equivalent parameters of the coating with the cavities are obtained,and the transfer function method is further used to obtain the expression of sound absorption coefficient.The correctness of the algorithm is verified by the comparison with the finite element numerical results.Particularly,this paper focuses on the resonance of cylindrical cavity monopole to explain the sound absorption mechanism of the coating,and shows the influence regulation of main parameters on the sound absorption performance from the perspectives of sound absorption curve and coating displacement diagram.This work provides a guidance for the design of low-frequency and high-absorption acoustic coatings.