航空发动机燃油系统定压活门参数优化设计

Optimization Design of Constant Pressure Valve Parameters of Aeroengine Fuel System

定压活门在燃油系统中为多个伺服机构供油,针对其稳定性、稳态精度、鲁棒性等设计要求,以及多个设计参数相互竞争又相互矛盾的选择,提出了一种基于优化算法的参数设计方法。建立了定压活门数学模型,基于稳态模型进行了参数设计分析。结果表明:定压活门存在流量稳态工作区,在流量稳态工作区内,阀芯截面积增大,流量敏感度增大,但阀芯截面积过大会增大定压活门的体积。根据定压活门压力范围计算了稳态参数,以调节时间和超调量为目标,取3组不同定压腔容积,将弹簧腔容积、阻尼孔径、运动阻尼、阀芯质量作为参数,基于非支配排序遗传算法(NSGA-Ⅱ)进行了动态优化。Pareto解集表明调节时间和超调量相互矛盾。选取1组解经AMESim仿真验证,优化后的结构参数能够使调节时间缩短20%以上,超调量降低15%以上,定压活门动态性能得到改善。

The constant pressure valve supplies fuel to several servo mechanisms in the fuel system.Aiming at its design require⁃ments of stability,steady-state accuracy,robustness,and the competing and contradictory selection of multiple design parameters,a parameter design method based on optimization algorithms was proposed.The mathematical model of the constant pressure valve was established,and parameter design analysis was conducted based on the steady-state model.The results show that there is a steady flow operating range in the constant pressure valve,within this range,as the cross-sectional area of the spool increases,the flow rate sensitivity increases,but excessive cross-sectional area of the spool will increase the volume of the constant pressure valve.The steady-state parameters were calculated based on the pressure range of the constant pressure valve.With the adjusting time and overshoot as the goal,three groups of different constant-pressure chamber volumes were taken for conducting dynamic optimization based on the non-dominated sorting genetic algorithm(NSGA-Ⅱ)with the spring chamber volume,the diameter of damping aperture,the motion damping,and the spool mass as parameters.The Pareto solution set indicates that the adjusting time and the overshoot amount are contradictory.A set of solutions was selected and verified by the AMESim simulation.The optimized structural parameters can shorten the adjusting time by more than 20%,reduce the overshoot by more than 15%,and improve the dynamic performance of the constant pressure valve.