临近空间大气密度扰动对高超声速飞行器气动热环境的影响

基于TIMED/SABER 2002—2018年大气密度观测数据，统计分析了20~80 km大气密度扰动对高超声速飞行器飞行热环境的影响。根据驻点热流估算方法给出的大气密度变化量与热流变化量之间的关系，定性和定量分析了不同月份大气密度相对变化量引起的热流变化量在垂直和水平方向的分布特征。研究表明:SABER大气密度月年均值计算的热流相对USSA76在夏季半球中高纬度地区偏高，在冬季半球偏低。在夏季半球高纬度地区约80 km附近存在热流增量的极大值，南半球夏季的极大值高于北半球夏季，尤其在南半球1月份，热流偏高可达32.2%。在经度方向，热流分布在夏季半球差异较小，冬季半球差异较大；考虑真实大气中存在的扰动时，在南半球和北半球夏季80 km附近，SABER大气密度预测的热流分别比USSA76偏高可达40.7%和36.6%。在经度方向，大气扰动引起的热流经向分布差异显著。在飞行器设计时，大气扰动的影响不能忽略；高超声速飞行器飞行应避免在夏季穿越南半球和北半球，规避热流增加带来的风险。 

Influence of atmospheric density disturbance on aerothermodynamic environment of hypersonic vehicles in near space

Based on the observation data of TIMED/SABER from 2002 to 2018, atmospheric density influence on aerothermodynamic environment of hypersonic vehicles is analyzed at 20-80 km. Based on the estimation method of heating transfer on stagnation in engineering, the relationship between the atmospheric density variations and the heating transfer changes is used to analyze the distribution characteristics of heating transfer changes in the vertical and horizontal directions qualitatively and quantitatively. The results show that: compared with the heating transfer calculated by USSA76, the heating transfer calculated by monthly mean density of SABER is higher in the middle and high latitudes in the summer hemisphere and lower in the winter hemisphere. There is a maximum value of heating transfer increments around 80 km in high latitudes of summer hemisphere. In summer, the maximum value of heating transfer increments in the southern hemisphere is higher than that of the northern hemisphere. Especially in January of southern hemisphere, the maximum value can reach 32.2%. In the longitude direction, the distribution of heat transfer in the summer hemisphere shows a small difference, while the heating transfer distribution in the winter hemisphere is significantly different. Considering disturbances in the real atmosphere, the heating transfer predicted by SABER is higher than that of USSA76 by up to 40.7% and 36.6% in summer of the southern and northern hemispheres around 80 km, respectively. In the longitude direction, the distribution of heating transfer caused by atmospheric disturbance is significantly different. Therefore, the effects of atmospheric disturbances on hypersonic vehicles cannot be ignored in the vehicle design process. Hypersonic vehicles should avoid crossing the southern or northern hemispheres during the summer to avoid the risk of increased heating transfer.