We obtain the reflection and transmission coefficients for inhomogeneous plane waves incident on a flat interface separating two double-porosity media described by the Biot–Rayleigh model, which takes into account the effect of local fluid flow (LFF). Three longitudinal and one transverse waves are reflected and transmitted, represented by potential functions specified by the propagation and attenuation directions. The continuity of the energy at the interface for sealed and open-boundary conditions yields a system of equations for the coefficients, and the expressions of the energy ratios for the reflected and refracted waves are derived in closed form. Numerical examples showing the magnitude, phase and energy ratio as a function of frequency and incidence angle are carried out to investigate the influence of the inhomogeneity angle, boundary condition, type of incidence wave and LFF effect. The results confirm that the LFF affects the reflection and transmission behaviors for the incident P1 and SV waves, irrespective of whether the interface is open or sealed. The effect causes interference fluxes between different waves, a consequence of energy conservation at the interface. We also perform full-waveform simulations to validate the results.

中文翻译：

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两种双孔隙介质界面处平面弹性波的反射和传输：局部流体流动的影响

我们获得了入射在由 Biot-Rayleigh 模型描述的分隔两种双孔隙介质的平坦界面上的非均匀平面波的反射和透射系数，该模型考虑了局部流体流动 (LFF) 的影响。三个纵波和一个横波被反射和传输，由传播和衰减方向指定的势函数表示。密封和开放边界条件下界面处能量的连续性产生了系数方程组，并且反射波和折射波的能量比的表达式以封闭形式导出。数值例子显示了作为频率和入射角函数的幅度、相位和能量比，以研究不均匀角的影响，边界条件、入射波类型和 LFF 效应。结果证实，LFF 会影响入射 P1 和 SV 波的反射和传输行为，无论界面是打开还是密封。该效应导致不同波之间的干扰通量，这是界面能量守恒的结果。我们还进行了全波形仿真以验证结果。