Thermoacoustic wave propagation in hydrodynamic poroelastic media with temperature-dependent thermal conductivity

This work presents a generalized theoretical model of thermoacoustic wave propagation in saturated poroelastic media that incorporates hydrodynamic interactions and variable thermal conductivity. The model integrates generalized thermoelasticity and Biot's poroelastic theory with a temperature-dependent heat conduction law to describe coupled thermal, mechanical, and acoustic processes in a fluid-saturated porous medium. The governing system includes equations of motion, Darcy-type fluid flow, and a generalized heat conduction equation in which the thermal conductivity varies nonlinearly with temperature. The normal mode analysis technique is applied to obtain analytical expressions for the field variables in one-dimensional form. Numerical simulations illustrate the influence of the thermal conductivity variation parameter, porosity, and hydrodynamic coupling on the thermoacoustic wave behavior. The results reveal that variable conductivity significantly modifies the amplitude, phase velocity, and attenuation of thermal and acoustic waves, particularly under transient heating. The proposed framework offers enhanced theoretical insight into the sensitivity of thermoelastic, acoustic, and pore-pressure waves to temperature-dependent conductivity, providing a foundation for future calibration against experimental observations in porous semiconductors, geophysical rocks, and engineered porous composites.