高超声速巡航气动参数/轨迹联合优化与算法比较

Integrated Optimization of Aerodynamic Parameters and Trajectory for Hypersonic Cruise Flight and Algorithm Comparison

针对高超声速稳态巡航飞行的气动参数/轨迹联合优化问题,设计了嵌套形式的两级优化器。其中,内层优化器针对巡航轨迹进行优化,优化算法选用序列二次规划算法(Sequential Quadratic Programming,SQP);外层优化器基于巡航轨迹的优化结果,对气动参数进行优化,分别采用序列二次规划算法、遗传算法(Genetic Algorithm,GA)和基于两者的混合算法进行优化。对整个联合优化问题进行了描述,对嵌套联合优化的方法优势和流程进行了说明。给出了嵌套优化器在内外2层的优化模型,包含设计变量、目标函数和约束条件。最后,进行了多组联合优化仿真,得到了巡航航程随升阻比提高的优化幅度曲线。同时,对不同外层优化算法下的优化全局性、计算效率等进行了对比分析,并结合各方法的优缺点,给出了实际优化问题中优化算法选用的建议。

To solve the integrated optimization problem of aerodynamic parameters and trajectory for hypersonic steady-state cruise,a nested two-level optimizer is designed.The inner loop is for cruise trajectory optimization using Sequential Quadratic Programming(SQP)algorithm,while the outer one is to optimize the aerodynamic parameters based on the trajectory optimization result with the use of SQP,Genetic Algorithm(GA)and the hybrid of the two algorithms,respectively.The whole integrated optimization problem is described,and advantages as well as the procedure of the nested integrated optimization are illustrated.Then,the optimization models on both levels of the nested optimizer are given,including the design variables,objective functions and constraints.Finally,a group of optimizations are implemented,and the variation curve between the increase percentage in the cruise range and the lift-drag ratio improvement is acquired.In addition,the three algorithms utilized in the outer loop optimization are compared in terms of the globality of the optimal solution and the optimization efficiency.According to the advantages and disadvantages of the algorithms,some suggestions are given for the optimization algorithm choosing in the practical problems.