基于Pareto Frontier方法的气动发动机设计  

Air powered engine design based on Pareto Frontier

作　　者：刘林[1] 俞小莉[1] 胡军强[1] 陈平录[1] 

机构地区：[1]浙江大学机械与能源学院,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2009年第1期123-127,共5页Journal of Zhejiang University：Engineering Science

基　　金：国家教育部博士点专项基金资助项目(20020335079)

摘　　要：为建立气动发动机的设计方法，提出将功率和比功作为优化气动发动机工作性能的两个目标，将多目标优化理论中的Pareto解作为气动发动机的设计曲线．采用基于进化算法的多目标优化程序NSGA—Ⅱ求解得到了最大比功一功率曲线，以及发动机行程、径程比等发动机结构参数和进气压力、发动机转速、进排气门启闭相位等发动机运行参数随功率的变化规律曲线．通过分析这些规律曲线得出，气动发动机各参数调节的结果是使进气门关闭前的缸内压力尽可能高；不同功率下，比功最大的发动机行程均取该变量变化范围的上限；径程比的取值范围为0．4～0．6，设计功率不同，其取值也不相同，可根据设计目标进行选取．总结出基于多目标优化算法气动发动机设计的一般流程，验证了基于Pareto Frontier设计方法的有效性，为科学规范地设计气动发动机打下良好基础．Specific work and power were proposed as two objectives and the Pareto solution in the field of multi-objective optimization was used to act as designing curve in order to investigate the designing method of air powered engine. Evolutionary algorithm-based multi-objective program NSGA-Ⅱ was used to get the relation of maximum specific work with engine power and the relations of engine structure parameters like cylinder bore, ratio of cylinder bore to stroke and so on and operation parameters like injection pressure, engine speed, valve time and so on with engine power. The analysis results showed that the optimized parameters were trying to hold the cylinder pressure as high as possible before inlet valve cut off and the optimized stroke was the upper limit of its variation range. The ratio of cylinder bore to stroke ranged from 0.4 to 0.6 and different value corresponded to different power, so the ratio should be chosen according to the design objective. The multi-objective optimization based air engine designing procedure was proposed and the validity of Pareto Frontier designing method was verified which forms a basis for the air engine design.

关 键 词：气动发动机 设计方法 多目标优化 遗传进化算法 

分 类 号：TK472[动力工程及工程热物理—动力机械及工程]