Abstract: Under the trend of longer flight time and higher Mach number for near space hypersonic vehicle, contradiction between thermal protection effect and lightweight is more prominent. Thus, numerical simulation of influence of pyrolysis gases combustion on surface ablation of charring material was carried out and the result was compared with that of arcjet test. Numerical results show that pyrolysis gases combustion can lead to the reduction in thickness of the ablation layer. With the increase in aerodynamic heat, protective effect of pyrolysis gases combustion on surface char is more apparent. This study can provide technical support for the optimization design of thermal protection system of the next generation near space hypersonic vehicle.

Key words: pyrolysis gases combustion, charring material, hypersonic vehicle, surface ablation, aerodynamic heat