Numerical Investigation on Transpiration Cooling Performance of Oriented Porous Structure Under Local Block Conditions

With the development of an active thermal protection system (TPS) for hypersonic vehicles, reliability improvement and weight reduction of TPS are key issues to be considered. In this paper, an oriented porous structure (OPS) is proposed to solve the local overheating problem in transpiration cooling. The transpiration cooling performances are investigated in a two-dimensional computational domain using a local thermal nonequilibrium model. The cooling mechanisms of OPS and uniform porous structure (UPS) under local block conditions have been numerically analyzed and compared. The results show that OPS leads to effective cooling of the overheated region by regulating the coolant flow behavior, especially in the case of serious block conditions. The maximum temperature reduction can be up to more than 200 K, and the maximum optimization rate can reach up to 23% compared to UPS. Moreover, OPS consumes less coolant and uses less driving force to deliver coolant when reaching the same peak temperature as OPS. This study shows that OPS has a better thermal protection effect in transpiration cooling, which can improve the reliability of TPSs, and that OPS can also achieve the lightweight of the aircraft.