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为改善高速列车的气动性能,建立高速列车流线型头型多目标气动优化设计流程,以气动阻力和偶极子噪声源为优化目标,对高速列车流线型头型进行减阻降噪的多目标优化设计.建立高速列车流线型头型的三维参数化模型,并提取出5个优化设计变量,实现高速列车流线型头型的自动变形.采用批处理命令和脚本文件实现高速列车空气动力学计算网格的自动划分及高速列车绕流流场的自动计算.利用多目标遗传算法NSGA-II对优化设计变量进行更新,实现高速列车流线型头型的多目标自动寻优设计.通过研究优化目标与优化变量之间的相关性,得到影响优化目标的关键优化设计变量,进一步分析得到关键优化设计变量与优化目标之间的非线性关系.通过与原始流线型列车气动性能对比发现,优化后的流线型头型最大可使高速列车的气动阻力降低4.54%,使高速列车的偶极子噪声源减少4.95dB.
In order to improve the aerodynamic performance of high-speed trains, a multi-objective aerodynamic optimization design process of high-speed train streamlined head is established, and the multi-objective optimization design of drag-reducing and noise-reduction for the high-speed train streamlined head with aerodynamic drag and dipole noise source as the optimization objective The establishment of three-dimensional parametric model of streamlined head shape for high-speed train and five optimized design variables are extracted to realize the automatic deformation of streamlined head shape of high-speed train.Automatic deformation of high-speed train aerodynamics grid is realized by batch command and script file Division and high-speed train flow around the flow field.Using the multi-objective genetic algorithm NSGA-II to optimize the design variables to achieve high-speed train streamlined head multi-objective automatic optimization design.Through the study of optimization objectives and optimization variables The key optimization design variables that affect the optimization goal are obtained and the nonlinear relationship between the key optimization design variables and the optimization objective is further analyzed.Through the comparison with the aerodynamic performance of the original streamlined train, it can be found that the optimized streamlined head shape can make the maximum Aerodynamic drag on high-speed trains is reduced by 4.54%, making dipole noise for high-speed trains Sound source to reduce 4.95dB.