Wave-induced fluid flow and reflection/transmission of seismic waves at a fluid/double-porosity thermoelastic medium interface

Abstract

This study investigates the wave-induced fluid flow and reflection/transmission of seismic waves at the interface of a non-viscous fluid and a double-porosity thermoelastic (DPT) solid. The analytical reflection/transmission coefficients are calculated for two boundary conditions: wholly sealed and open pores using the displacement potentials and Gauss-elimination method. The wave-induced local fluid flow (LFF) is computed analytically using the transmission coefficients of transmitted waves in a DPT medium, and it found that four compressional waves contribute to wave-induced LFF. Further, the energy partitioning between reflected and transmitted waves is also computed. An energy matrix describes the amount of energy transmitted to the DPT medium. The matrix has five diagonal elements representing the five waves’ energy proportions with different properties. The total of all the non-diagonal elements in the matrix indicates the energy involved in the interaction between transmitted waves. A numerical example is considered to perform the computational analysis of distinct propagation characteristics. Finally, the impacts of incident direction, wave frequency, inclusion radius, and pores fluid viscosity on the wave-induced LFF and energy partitioning are investigated graphically. Finally, energy conservation for both kinds of surface pores is found.