汽车进气格栅多目标优化设计

基于kriging模型和NSGA-Ⅱ算法,采用多目标优化设计的方法研究了进气格栅对汽车气动性能和发动机舱散热性能的影响,并通过数据挖掘技术研究设计变量与目标函数间的影响机制。进气格栅优化变量有3个:格栅倾角、格栅条数量和格栅条宽度。优化目标为汽车的气动阻力系数、气动升力系数以及进入发动机舱的气流质量流量。通过总变差分析和自组织映射图分析,得出了各设计变量对不同目标的影响程度以及变量与目标之间和目标与目标之间的相互关系。最后对比分析了优化后的模型和原始模型的气动性能和发动机舱散热性能。

Multi-objective optimization design of auto air-inlet grille

Multi-objective optimization design method based on kriging model and NSGA-II algorithm is adopted to investigate the influence of air-inlet grille to aerodynamic performance and underhood cooling performance of vehicle. Data mining technologies including total variation analysis and self-organizing map analysis are used to uncover the influence mechanisms of design variables on objective functions. Three parameters of the grille including the grille inclination angle, the number and width of grille bar are chosen as design variables. The optimization objectives are the drag coefficient, the lift coefficient and the air mass flow-rate into the underhood of vehicle. Data mining results shows out the effect degrees of variables to objectives, the relationship between variables and objectives, and the relationship between objectives. At last, aerodynamic performance and underhood cooling performance of the optimized models and initial model are compared.