Stagnation-point radiation heating characteristics of hypersonic reentry vehicle

Aerodynamic heating characteristics of hypersonic reentry vehicle are the basis for the design of thermal protection, which include the convection heating and radiation heating. In general, the radiation heating is ignored except for some reentry vehicles with hypervelocity at low altitude. The stagnation-point radiation heating characteristics of hypersonic reentry were studied, the four band spectra model were used for high temperature air as that in QRAD software. Non-equilibrium effect and its truncation phenomenon were considered. Simulations were conducted for a typical hypersonic reentry vehicle, which has flight data of the radiation heating flux. The results indicate that the method developed in this paper can predict the stagnation-point radiation heating of hypersonic reentry vehicles. In low-altitude and hypersonic reentry area, the radiation heating becomes significant, and visible continuum spectrum radiation is the dominating component. The infrared lines spectrum and the ultraviolet lines spectrum radiation are also relatively distinguishable, while the ultraviolet continuum spectrum and non equilibrium spectrum radiation are insignificant. The radiation heating decreases along the stagnation centerline, and the radiation heating is mainly affected by the radius of the sphere, the flight height and the flight velocity.