Performance comparison of distributed injection methods for hypersonic film-cooling

摘要

Film-cooling is one of the promising technologies proposed to help mitigate the heat-transfer load experienced by hypersonic vehicles. To investigate this phenomena, fundamental testing of three different distributed Boundary-Layer (BL) injection methods was carried out in the T4 Stalker Tube using hydrogen injectant. A flat plate model was tested, using a cross-flow of air, at Mach 7.6; a dynamic pressure of 48 kPa; and a flight enthalpy of Mach 10. This fundamental testing was done to help characterize the performance and injection characteristics of different distributed injection methods. The three different injectors selected for this study were a porous Carbon/Carbon (C/C) Ceramic-Matrix-Composite (CMC); a porous oxygen compatible CMC; and a Multi-Port Injector Array (MPIA) optimised for scramjet conditions. Of these, the C/C CMC performed the best, overall, when examining the heat-transfer reduction for both a laminar and transitional-turbulent BL in a hypersonic cross-flow.