双层微穿孔结构扩散场吸声特性

本文在单层微穿孔结构的基础上，考虑到实际应用的声场条件和采用双层结构的要求，导出双层结构在扩用场中的声阻抗及吸声系数计算公式，分析了其在扩散场中的吸声性能，指出不能直接用垂直入射声波条件下的结果来判定某一双层结构在扩散场中吸声性能的优劣。并将理论计算结果和混响室中的测量结果进行比较，结果证明，理论计算可以较准确地预测实际结构的吸声性能。根据理论分析所设计的软件可以方便地进行双层或多层复合微穿孔结构

Absorbing property of mutilayer microperforated structure in diffuse field

In this paper,sound absorbing property of mutilayer complicated microperforated structure is analyzed, and formulae for its acoustic impedance and absorption coefficient in diffuse field were derived. Analysis shows that simply apply structure parameters from results of normal sound field for mutilayer structure in diffuse field could be misleaded.The theoretical model developed in this paper was proved by experiments in reverberation room and shows it can predict the absorption of varies mutilayer structures in good accuracy.The therefrom developed software can be easily used for designing of mutilayer complicated microperforated structure.