超低轨飞行器迎风面减阻构型优化研究

Optimization of drag reduction configuration on windward sideof very low orbit spacecraft

针对超低轨飞行器迎风面气动阻力过大的问题,在理论解求自由分子流气动阻力方法的基础上分析迎风面阻力的主要影响因素,计算不同长度下几种典型迎风面构型的气动阻力值并分析其变化原因。在此基础上设计迎风面构型的表达函数并引入智能算法对其迭代寻优。对构型存在的约束,引入罚函数机制以降低不可行解的适应度值。研究结果表明:此方法可获得最小阻力迎风面的近似最优解,在现有材料的约束下,相比锥形构型,优化方法最大减阻可达5%以上,并能有效增加飞行器头部容积;随迎风面高度上升,最小阻力构型从近台形逐渐向锥形转化。提出的构型优化方法,可为后续超低轨飞行器减阻构型设计提供参考。

Aiming at the problem that the windward side of very low orbit spacecraft is subjected to too much aerodynamic resistance,based on the theoretical solution to the aerodynamic drag of free molecular flow,the aerodynamic resistance of several typical windward side configurations with different length was calculated and the reasons for their changes were analyzed.After which an expression of the windward side was designed and an intelligent algorithm was introduced to iteratively optimize it.Given the constraints of the configuration,the penalty function was introduced to reduce the fitness of the infeasible solution.The results show that this method can obtain the approximate optimal solution of the windward side with minimum resistance.Under the constraints of existing materials,the maximum drag reduction of this method can be more than 5%compared with the conical structure,and the head volume of the spacecraft can be effectively increased.With the increase of windward height,the minimum resistance configuration gradually changes from near frustum to cone.The optimization method proposed in this paper can provide a reference for subsequent drag-reducing configuration design of very low orbit spacecraft.