液体火箭发动机系统设计仿真与优化

建立了某液体火箭发动机系统设计的仿真模型与相应的多目标优化模型,编制了系统仿真程序,并在iSIGHT的软件平台上针对不同的优化目标对发动机的设计参数进行优化.采用了组合优化策略,结合多岛遗传算法和序列二次规划算法分别进行全局寻优和局部寻优,求得全局最优点.建立了单燃气发生器循环系统的质量模型,在优化过程中考虑了发动机主要部件结构质量对系统性能的影响。以燃烧室压强、混合比和喷管出口反压为设计变量,优化目标包括发动机比冲、有效载荷、结构质量、密度比冲、关机时飞行速度、推进剂综合密度.并根据结果分析了燃烧室压强和混合比对发动机性能的影响.

Simulation and optimization of liquid propellants rocket engine for system design

The system simulation model and the relevant multi-objective optimization model were established for a type of liquid propellants rocket engine.A system simulation procedure was programmed.Design parameters of system were optimized owing to different optimization objectives on iSIGHT software platform.A type of hybrid algorithm,which combined the multi-island genetic algorithm and the sequential quadratic programming algorithm,was used to find global optimum in given design space during the optimization procedure.Weight model of single gas generator cycle system was established.Main components weights were concerned in optimization because of their influence on system performance.The optimization design variables were the combustor pressure,mixture ratio,and the outlet pressure of pipe.The optimization objectives were engine specific impulse,payload,engine weight,engine density specific impulse,flight speed at shutting down and engine compositive density.The effects of combustion chamber pressure and mixture ratio on engine performance were analyzed based on simulation.