Insulating and absorbing heat of transpiration in a combinational opposing jet and platelet transpiration blunt body for hypersonic vehicle

Abstract A platelet transpiration is introduced to the opposing jet thermal protection system (TPS) to enhance the cooling efficiency in hypersonic vehicles. In this study, the thermal protection performance of a combinational opposing jet and platelet transpiration blunt body is investigated. The surface heat flux is initially obtained by solving the three-dimensional compressible Reynolds averaged Navier–Stokes equations with Menter’s shear stress transport turbulence model. Then, the obtained heat flux is loaded to the blunt body to solve the temperature distribution. The cooling effect caused by insulating and absorbing heat of transpiration gas is obtained. Results show that the transpiration gas can insulate the partial aerodynamic heating in reattachment region and reduce the peak heat flux. The peak heat flux is reduced by 34.23% when mtran is 0.4 m0. In addition, the transpiration gas flowing in coolant passages can absorb the heat by heat convection and remove the absorbing heat. Consequently, the temperature is reduced by more than 300 K. Finally, the insulating and absorbing heat functions of transpiration coolant gas exhibit equal importance on cooling efficiency. The temperature drop caused by the insulating and absorbing are distinguished obviously. Hence, they should be considered in the transpiration cooling TPS.