天宫飞行器低轨控空气动力特性一体化建模与计算研究

Unified Modeling and Calculation of Aerodynamics Characteristics during Low-Orbit Flying Control of the TG Vehicle

对非规则板舱组合体天宫飞行器300～200km低轨道飞行过程空气动力特性一体化计算建模，提出考虑复杂构型物面遮盖效应面元解析法与经修正的Boettcher／Legge非对称桥函数，发展基于三角形面元逼近复杂外形通用处理方法，建立适于天宫飞行器复杂物形处理与面元气动力系数计算规则；将DSMC方法与求解Boltzmann模型方程气体运动论统一算法应用于天宫飞行器简化外形，进行气动力当地化关联参数计算修正，建立针对大型复杂结构天宫飞行器低轨道飞行控制过程空气动力特性一体化快速算法与程序软件。对大尺度圆柱体外形与天宫飞行器300～200km不同高度变轨飞行过程不同迎角与侧滑角及帆板平面与本体主轴不同夹角复杂构型气动力特性计算分析验证，表明天宫飞行器在200km以上低轨道飞行控制过程中所受空气动力系数随飞行高度发生显著变化（8％～50％），证实长期在轨运行的大型航天器若采用统一固定的气动力系数，误差累积巨大，需要采取防护措施，低轨道飞控大气阻力仍是制约航天器定轨预报精度最关键因素。

The surface analytical method,considering surface shielding effect of the complex structure and the modified Boettcher / Legge nonsymmetric bridge correction function,was proposed to computationally model aerodynamic characteristics of the large-scale Tiangong spacecraft of irregular plate-capsule assembly. The complex configuration processing and computing rules of surface element aerodynamic coefficients were set up by developing a general triangle element approximation for complex shapes. A unified fast algorithm and computing software for aerodynamic characteristics of large-scale complex spacecraft structures were developed,by computing correction of local correlation parameters during Tiangong spacecraft 's low-earth orbit flight control,in which the DSMC method and the gas-kinetic unified algorithm solving the Boltzmann model equation were applied. It is indicated that,by computing the aerodynamics of the Tiangong spacecraft in 300 ~ 200 km altitude-orbit flight process,with various flying heights,various angles of attack and various angles between the panel and the principal axis,the aerodynamic coefficients varied remarkably,with a range of 8% ~ 50%,with the altitude change,and the atmospheric drag in low-earth orbit flight control was the key factor of the spacecraft orbit prediction accuracy. It is validated that,if the fixed and constant unity aerodynamic coefficient is used for long-term orbit flight of a large spacecraft,the error accumulation will be huge,and protective measures are needed.