高超声速飞行器变比热驻点热流计算

 为快速准确预测高超声速飞行器驻点热流密度,基于P-R 状态方程,计算空气真实气体状态下比热比、定压比热容,得到温度拟合公式。应用变比热计算了高超声速飞行器激波后温度,应用空气真实气体状态下定压比热容计算了典型的高超声速钝头体驻点热流密度值。计算结果与实验值基本吻合,表明计算方法可行,有足够的精度,可为高超声速飞行器初步设计热环境计算和防热材料的合理选择提供可靠的参考数据。

The calculation of the heat flux at the stagnation point in consideration of variable specific heat for hypersonic vehicle

In order to design a thermal protection system for hypersonic vehicles, it is important to predict the heat transfer rate precisely. For this purpose, an effective method for calculating the heat flux at the stagnation point for hypersonic vehicles is developed. The variable specific heat of air is considered in the calculation of changes of temperature behind the shock wave, while the effect of real gas is considered in the calculation of the heat flux at the stagnation point. The air's heat capacity and the ratio of the specific heat are calculated based on the Peng-Robinson equation of state, and their fitting formula can be obtained against temperature. The typical stagnation point heat flux for a blunt body is calculated. The results are compared with the experimental data and data from the fitting formula in literature. The results show that the method is convenient and accurate. Reliable data can be provided for the aero-thermal calculation in the initial design and for the reasonable choice of the thermal protection system for hypersonic vehicles.