Multi-field analysis of flow, heat transfer and mechanical behavior in porous media for transpiration cooling based on one-way coupling assessment

A bstract Transpiration cooling realizes thermal protection via coolant delivery in porous structures, but its efficiency can be compromised by pore morphology changes induced by intense thermo-mechanical deformation in high-temperature environments. This research presents a coupled analysis of flow, heat transfer, and mechanical behavior for transpiration cooling. A one-way coupled theoretical model is established that accounts for fluid flow, conjugate heat transfer, and thermally driven elastoplastic deformation. Under baseline conditions, the heated surface is fully in plastic deformation, with thermal strain of 4.92% at the leading edge, porosity compressed from 0.20 to 0.159, and permeability reduced to 45.1%, and meanwhile, a potential self-reinforcing deterioration mechanism is inferred based on the one-way results, where porosity reduction leads to permeability degradation. Increasing the injection ratio from 0.6% to 0.9% reduces thermal strain by 4.46% and increases permeability ratio by roughly 4.39%. Lower initial porosity improves cooling effectiveness while maintaining similar absolute porosity reduction. Oblique shocks cause local thermal and mechanical intensification. At 8° and 12° wedge angles, plastic strain at the shock impact point approaches that at the leading edge, forming a second critical coupling region. This investigation reveals the underlying coupling mechanism, offering a theoretical basis for optimizing transpiration cooling systems.