Investigation on efficient utilization of heat sink in transpiration cooling

The reasonable distribution of coolant heat sink is an effective way to solve thermal ablation and improve the thermal protection effect of transpiration cooling. Intermittent transpiration cooling has a higher cooling efficiency than single transpiration cooling due to the fact that there is more mount of coolant near the starting position of transpiration cooling. The appearance of the shock wave leads to a sudden increase in temperature near the discontinuous interface and the appearance of the expansion wave leads to a negative blow-off strength near the impermeable wall. Although the continuous increase of the injection ratio can reduce the wall temperature, there is a lot of waste in the potential heat sink, which inhibits the endothermic power. As the Mach number increases, the variance of wall temperature increases, which makes the wall temperature difference of porous media at different positions increase, and weakens the blowing strength, but the potential heat sink is better utilized. Optimizing the porosity can make more coolant reach the upstream region and cover the downstream, and the temperature uniformity is improved. However, when the porosity of the left porous medium is too large, the downstream will have the problem of insufficient cooling.