Numerical simulation of the effects of double blocking regions on transpiration cooling in directional porous structures

This study uses numerical simulations based on the local thermal non-equilibrium model to investigate the effects of varying intervals between two blocking regions on the transpiration cooling performance of directional porous structures. Numerical methods illustrate the complex thermal interactions within the porous structure, enabling a detailed analysis of temperature distribution and heat transfer mechanisms. The results indicate that as the blocking intervals increase, the maximum temperature of the porous structure first decreases and then rises. A relationship is established between the degree of orientation and the inflection point in maximum temperature corresponding to the blocking interval. For isotropic structures, negligible interaction between the two blocking regions occurs when the blocking interval is approximately five times the width of the blocking region, while for directional structures with ϵ_x = 0.001, this interaction becomes negligible at an interval equal to the width of the blocking region. Additionally, the depth of the blocking region plays a crucial role. Under the same coolant injection rate, the maximum temperature of the directional structure is reduced by more than 200 K compared to the isotropic structure. Furthermore, the maximum temperature of the porous structure with two blocking regions is ∼50 K lower than that of a structure with a single blocking region. These findings contribute to assessing the performance of porous structures under blockage conditions and provide an overview for addressing potential issues in next-generation thermal protection systems.