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.%高超声速再入飞行器的热环境特性是热防护设计的重要基础.它主要包括辐射加热和对流加热,一般情况辐射加热较小可以忽略,但部分再入飞行器在低空还具有极高的速度,辐射加热不能忽略.本文针对高超声速再入飞行器驻点的辐射加热特性开展了研究,采用高温空气辐射加热的四光谱带模型,同时计算方法中考虑了非平衡辐射加热及其"截断效应".计算结果表明,在低空高速再入阶段,辐射加热比较明显,热防护设计需要考虑辐射加热.辐射加热主要由可见连续光谱辐射构成,红外线谱和紫外线谱的辐射加热也比较明显,紫外连续谱辐射以及非平衡辐射效应均不明显.辐射加热沿球头驻点至球头外边缘逐渐减小,影响辐射加热的主要因素有头部半径、飞行高度和飞行速度.
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