Numerical study on thermo-mechanical behavior on porous medium matrix in phase-change transpiration cooling

This work focuses on analyzing the thermo-mechanical behavior of superalloy particle-sintered porous medium in phase-change transpiration cooling using the Local Non-Thermal Equilibrium Two-Phase Mixture Model (LNTE-TPMM). Under non-uniform heat flux, the porous medium forms temperature gradients in both x and y directions, triggering coupled thermo-mechanical responses; the upper surface enters the plastic regime, with the left high-heat-flux zone enduring the most severe thermal impact and reaching a maximum thermal strain of 1.77 %. Increased heat-flux non-uniformity exacerbates the non-uniformity of coolant mass flux and solid temperature, further amplifying fluctuations in thermal stress and strain. Enhancing the coolant mass flux effectively mitigates thermo-mechanical coupling by homogenizing flow and temperature distributions, curbing the growth of thermal stress and reducing thermal strain. Higher coolant inlet temperature modulates the coupling intensity by altering the physical properties of the coolant and the driving force for evaporation, which homogenizes mass flux and surface temperature while increasing the overall level of thermal strain. These findings provide key theoretical support for optimizing the reliability and longevity of phase-change transpiration cooling systems in extreme thermal environments.