3-D wave propagation in a general anisotropic poroelastic medium: reflection and refraction at an interface with fluid

Abstract

SUMMARY Reflection/refraction process is studied to calculate the energy distribution and transmission in a general anisotropic poroelastic solid half-space in contact with a fluid half-space. Biot's theory is used to study the propagation of plane harmonic waves in an anisotropic fluid-saturated porous solid. Snell's law for reflection/refraction at an interface between fluid and anisotropic poroelastic solid is calculated for the wave propagation in three dimensions. From the velocity and direction of incident wave in the fluid medium, Snell's law is used to find the phase velocities and phase directions of all the four refracted waves. The phase velocity and phase direction, thus, obtained are used to calculate the group velocity and ray direction of each of the refracted waves. The energy of the incident wave is distributed among one reflected wave and four quasi-waves refracted to the anisotropic poroelastic medium. Energy transmission with each of the reflected/refracted waves is studied along with their directions of travel in 3-D space. The variations of energy partition with the direction of the incident wave are computed for a particular model. The effect of azimuthal anisotropy on the partition and transmission of energy is observed.