高焓化学非平衡流条件下C/SiC复合材料的催化性能

Ultrahigh temperature ceramic matrix composite (C/SiC) is one of the key materials for the Thermal Protection System (TPS) of near space vehicles. The catalytic performance of the C/SiC material in the high enthalpy chemical non-equilibrium flow is the key parameter of the design, optimization and accurate evaluation of the thermal protection system of the hypersonic flight vehicle. Using the high frequency plasma wind tunnel, the surface catalytic recombination coefficients of C/SiC were determined at the surface temperature range of 1453-2003 K, in the high disassociated air with the enthalpies of 19.3-35.9 MJ/kg, and with the stagnation pressures of 1.0,1.8,3.30 and 6.0 kPa. It shows that the catalytic recombination coefficient of C/SiC under high surface temperature condition depends not only on the surface temperature but also on stagnation point pressure and the partial pressure. According to the catalytic results, the aerothermal parameters for the typical America reentry flight (H=73 km,U=6.478 km/s, R_n=410 mm) with blunt body using C/SiC and its surface temperature history with test catalytic data and full-catalytic have been carried out. The results have strengthened that accurate estimation of the aerodynamic heating and temperature response to thermal protection system are greatly affected by catalytic performance of thermal protection material.