低轨卫星的气动特性预测与分析

针对低轨卫星高空自由分子流区的飞行环境特征,采用GOCE卫星典型弹道下的气动数据对DSMC仿真方法进行了算例验证,并就CLL模型下不同物面反射系数对GOCE卫星流场特征及气动特性的预测差异进行了对比分析,给出不同物面反射系数对卫星阻力预测的定量差异.结果表明,本文方法所得气动阻力与文献结果吻合较好,能够在此飞行区域给出合理的气动阻力;当反射系数从0.1逐渐变化至1.0时,卫星流场的驻点区域、尾部方向舵区域压力分布逐渐从带状结构向扇形结构过渡;在所研究的工况下,随着物面反射系数的增加,摩阻系数预测结果偏大,压阻系数预测结果偏小,总阻力先增加后减小,约在反射系数0.8附近达到最大. 

Numerical Investigation of Aerodynamics on Low Earth Orbit Satellite

DSMC code is validated with GOCE satellite free molecule aerodynamics data in\linebreak reference. The difference of GOCE satellite flow field and aerodynamic characteristics computed with different wall reflect coefficient is shown. Results show that the drag force coefficient computed by present code is in good agreement with that of the reference. When the wall reflection coefficient is changed from 0.1 to 1.0, the pressure distribution at the local stagnation and wing head region is shown to change from banded structure to ellipse structure. With the wall reflection coefficient increasing, the friction drag coefficient increases, and the pressure drag coefficient decreases, which results in that the total drag coefficient increases firstly, decreases then, and reaches its maximum when the wall reflection coefficient is about 0.8.