基于Sobol′灵敏度分析的火箭弹自力弹射多目标约束优化

Multi-Object Constraint Optimization of Rocket Self-Ejection Based on Sobol′ Sensitivity Analysis

关键词:  Sobol'法  灵敏度分析  火箭弹  自力弹射  约束优化

Key words:  Sobol' method  Sensitivity analysis  Rocket  Self-ejection  Constraint optimization

摘要:

火箭弹自力弹射过程中燃气被限制在低压室内，低压室压强使得出筒速度增加的同时也增大了发射装置受力。为完成自力弹射的多目标约束优化，首先建立了发动机-低压室耦合内弹道模型，开展实弹试验对模型进行了验证；其次采用Sobol'全局灵敏度分析法，以低压室压强峰值和弹体出筒速度为目标响应，求得各设计参数的灵敏度数据；最后以低压室压强峰值最小和弹体出筒速度最大为优化目标，基于灵敏度数据建立自力弹射多目标约束优化模型，采用NSGA-II算法进行求解。结果表明，发动机装药量对低压室压强峰值及出筒速度的影响最为显著，低压室初始长度对低压室压强峰值影响较大，低压室开孔数量对弹体出筒速度影响较大；在Pareto最优前沿上选取10个备选方案并采用逼近理想解排序法排序。相较于初始方案，排序得到的最终优化方案的低压室压强峰值降低13.41%，弹体出筒速度增加52.56%，自力弹射性能得到提升。

Abstract:

The exhaust plume is sealed in low pressure chamber during the process of rocket self-ejection， the pressure in low pressure chamber leads to an increase of the exit velocity and the force exert on the launcher. In order to complete the multi-object constraint optimization for self-ejection， firstly a motor and low pressure chamber coupled internal ballistic model was developed. The validity of interior ballistic model was verified by physical tests. Secondly sensitivity data of the main parameters aiming at the pressure peak of low pressure chamber and exit velocity was calculated by Sobol' global sensitivity analysis method. Finally the multi-object constraint optimization model with minimum pressure peak in low pressure chamber and maximum exit velocity was set up based on sensitivity data， the optimization model was calculated by NSGA-II. The results show that， the propellant mass has the greatest influence on pressure peak of low pressure chamber and rocket exit velocity， the initial length of low pressure chamber has the second largest influence on pressure peak of low pressure chamber， the number of hole on the wall of low pressure chamber has the second largest influence on exit velocity. Ten schemes were selected in Pareto front and ranked using technique for order preference by similarity to an ideal solution. Compared with the initial scheme， the peak of pressure in low pressure chamber of the final optimized scheme decrease 13.41%， the exit velocity of the final optimized scheme increase 52.56%，the performance of self-ejection has been improved.