Reflection of acoustic wave from the elastic seabed with an overlying gassy poroelastic layer
Reflection of acoustic wave from the elastic seabed with an overlying gassy poroelastic layer
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声波从具有上覆气体多孔弹性层的弹性海底反射
DOI：
10.1093/gji/ggv266
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发表时间：
2015
影响因子：
2.8
通讯作者：
Li Xiaojun
中科院分区：
文献类型：
--
作者：
Chen Weiyun;Wang Zhihua;Zhao Kai;Chen Guoxing;Li Xiaojun
基于多相孔隙弹性理论，研究了斜入射声波在上覆水体与下伏弹性固体海床的海洋气相沉积层平面界面上的反射特性。将夹层气体层建模为具有有限厚度的多孔材料，该材料被两种可压缩粘性流体（液体和气体）饱和。根据模型中上下界面的边界条件，从理论上导出了反射波振幅比的封闭表达式，即反射系数。通过数值计算，分别分析了夹层多孔层的层厚、入射角、波频和液体饱和度对反射系数的影响。结果表明，反射系数与入射角和夹层厚度密切相关。此外，在不同的频率范围内，波浪反射特征对海洋中间沉积层水分（或气体）变化的依赖是有区别的。
Based on the multiphase poroelasticity theory, the reflection characteristics of an obliquely incident acoustic wave upon a plane interface between overlying water and a gassy marine sediment layer with underlying elastic solid seabed are investigated. The sandwiched gassy layer is modelled as a porous material with finite thickness, which is saturated by two compressible and viscous fluids (liquid and gas). The closed-form expression for the amplitude ratio of the reflected wave, called reflection coefficient, is derived theoretically according to the boundary conditions at the upper and lower interfaces in our proposed model. Using numerical calculation, the influences of layer thickness, incident angle, wave frequency and liquid saturation of sandwiched porous layer on the reflection coefficient are analysed, respectively. It is revealed that the reflection coefficient is closely associated with incident angle and sandwiched layer thickness. Moreover, in different frequency ranges, the dependence of the wave reflection characteristics on moisture (or gas) variations in the intermediate marine sediment layer is distinguishing.