动车组车体断面气动外形优化研究

Study on Aerodynamic Shape Optimization of EMU Body Section

动车组横截面外形与其横风空气动力学性能息息相关,是影响动车组横风效应的关键因素。为了实现动车组横截面的气动外形优化,文中采用一套高效的气动外形优化策略对某型动车组横截面进行优化研究。首先,通过求解N-S方程得到强横风条件下列车周围的流场信息,利用遗传算法寻求全局最优解,利用任意几何变形技术直接改变截面形状和网格,节省重构网格的时间。将三者结合起来,显著地提升了优化效率,极大地节省了优化的时间。其次,优化结束后再对设计空间中的设计点进行统计分析,得到设计变量与优化目标的相关性,得到影响优化效果的关键设计变量,并对其使用Kriging代理模型进行响应面分析,得到关键设计变量与优化目标之间的非线性关系。研究结果可以为动车组在横风条件下的气动外形设计提供一定的技术指导。

The cross-sectional shape of high-speed train is closely related to its cross wind aerodynamic performance,which is the key factor affecting the cross wind effect of high-speed train.In order to optimize the aerodynamic shape of the cross section of a high-speed train,a set of efficient aerodynamic shape optimization strategy is used to optimize the cross section of a high-speed train.The flow field information around the train under strong cross wind is obtained by solving the N-S equation.The global optimal solution is sought by genetic algorithm,and the section shape and mesh are directly changed by arbitrary geometric deformation technology to save the time of mesh reconstruction.This paper combines the three,significantly improves the optimization efficiency and greatly saves the optimization time.Secondly,after the optimization,the design points in the design space are statistically analyzed to obtain the correlation between the design variables and the optimization objectives,the key design variables affecting the optimization effect are obtained,and the Kriging agent model is used for response surface analysis to obtain the nonlinear relationship between the key design variables and the optimization objectives.The research results of this paper can provide some technical instructions for the aerodynamic shape design of high-speed train under cross wind conditions.