声波在两种多孔介质界面上的反射和透射

REFLECTION AND TRANSMISSION OF ACOUSTIC WAVE AT A POROUS SOLID/POROUS SOLID INTERFACE

本文导出了声波在两种多孔介质界面上反射、透射的一般计算公式.作为例子,数值计算了P_1波入射于界面时,P_1、P_2和S波的反射、透射系数与声波频率、入射角等量之间的关系.结果表明,各种模式波的反射、透射系数与入射角、多孔介质性质有关,在Biot特征频率附近与频率有关,并用界面两侧的法向能流相等验证了结果的正确性.若把多孔介质当作均匀固体处理,将会得到显著不同的结果.

The calculating formulas of reflection and transmission for plane acoustic wave on an interface between porous solid/porous solid are studied in this paper. The dependance of reflection and transmission coefficients of various bulk waves on acoustic frequency, incident angle, porous solid parameters etc. are calculated for the case that the incident wave is the first kind of compressional wave. The numerical investigation is checked by equilization of energy flux crossing interface in normal direction. Our results show that the reflection and transmission coefficients of various bulk waves are sensitive to incident angle of acoustic wave, medium properties as well as the frequency near the Biot critical frequency. The first kind of compressional wave and the second kind of compressional wave are mainly existed in frame and fluid respectively. Also, if the porous solid is simulated by isotropic solid, the results will be much different.