弹性固体和充满两种互不相溶粘性流体的多孔固体之间界面的反射和折射及其衰减波

Reflection and Refraction of Attenuated Waves at the Boundary of an Elastic Solid With a Porous Solid Saturated With Two Immiscible Viscous Fluids

在充满两种互不相溶粘性流体的多孔固体中,研究弹性波的传播.用3个数性的势函数描述3个纵波的传播,用1个矢性的势函数单独描述横波的传播.根据这些势函数,在不同的组合相中,定义出质点的位移.可以看出,可能存在3个纵波和1个横波.在一个弹性固体半空间与一个充满两种互不相溶粘性流体的多孔固体半空间之间,研究其界面上入射纵波和横波所引起的反射和折射现象.由于孔隙流体中有粘性,折射到多孔介质中的波,朝垂直界面方向偏离.将入射波引起的反射波和折射波的波幅比,作为非奇异的线性代数方程组计算.进一步通过这些波幅比,计算出各个被离散波在入射波能量中所占的份额.通过一个特殊的数值模型,计算出波幅比和能量比系数随入射角的变化.超过SV波的临界入射角,反射波P将不再出现.越过界面的能量守恒原理得到了验证.绘出了图形并对不同孔隙饱和度以及频率的变化,讨论它们对能量分配的影响.

The propagation of elastic waves was studied in a porous solid saturated with two immiscible viscous fluids.The propagation of three longitudinal waves was represented through three scalar potential functions and a vector potential function represents the lone transverse wave.Displacements of particles in different phases of the aggregate were defined in terms of these potentials functions.It was shown that there could exist three longitudinal waves and one transverse wave.The phenomenon of reflection and refraction due to longitudinal and transverse wave at a plane interface between an elastic solid half-space and a porous solid half-space saturated with two immiscible viscous fluids were investigated.For the presence of viscosity in pore-fluids,the waves refracted to porous medium attenuated in the direction normal to the interface.The ratios of amplitudes of reflected and refracted waves with that of the incident wave were calculated as a non-singular system of linear algebraic equations.These amplitudes ratios were used further to calculate the shares of different scattered waves in the energy of incident wave.Variations of modulus of amplitude and energy ratios with the angle of incidence were computed for particular numerical model.For post-critical incidence of SV wave,the reflected P wave became evanescent.The conservation of energy across the interface was verified.The effects of variations in non-wet saturation of pores and frequency on the energy partition were depicted graphically and discussed.