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目的:为改善高速列车明线运行时的气动性能,提出一种基于近似模型的高速列车头部外形多目标气动优化设计方法。创新点:1.建立包含转向架区域的高速列车参数化模型;2.基于近似模型并结合遗传算法,对高速列车头部外形及转向架区域进行多目标气动优化设计。方法:1.建立包含转向架区域的原始头型高速列车模型(图2和3),并基于CATIA脚本文件和MATLAB自编程序对列车头部外形进行参数化处理;2.通过最优拉丁超立方设计方法在设计空间内对优化设计变量进行采样,并采用计算流体动力学方法对样本点中新头型列车气动性能进行计算;3.基于样本点的列车头型优化设计变量及优化目标(表4),建立优化目标与设计变量之间的近似模型;4.基于近似模型和多目标遗传算法,对高速列车头部外形进行多目标优化设计,选取其中的一个优化头型与原始头型进行比较,并验证横风下优化头型的可行性。结论:1.相较于原始头型列车,无横风时,优化头型列车的整车气动阻力减小2.61%,尾车气动升力减小9.90%;2.横风下,优化头型列车的整车气动阻力减小2.98%,头车气动侧力减小0.24%;3.横风下,优化头型列车的头车气动载荷波动幅值有所减小。
Objective: To improve the aerodynamic performance of high-speed train during open-line operation, a multi-objective aerodynamic optimization design method for high-speed train head profile based on approximate model is proposed. Innovative points: 1. Establishing a parametric model of high-speed train with bogie area; 2. Based on approximate model and genetic algorithm, multi-objective aerodynamic optimization design of high-speed train head shape and bogie area. Methods: 1. Establish the original head-type high-speed train model (Figure 2 and 3) containing the bogie area, and parameterize the train head shape based on the CATIA script file and MATLAB self-programming; The cubic design method samples the optimal design variables in the design space and calculates the aerodynamic performance of the new-style train in the sample points by the computational fluid dynamics (CFD) method.3. Optimization design variables and optimization objectives of the train head based on the sample points Table 4), to establish an approximate model between optimization objectives and design variables; 4. Based on the approximate model and multi-objective genetic algorithm, multi-objective optimization design of high-speed train head shape, select one of the optimized head type and the original head type Compare and verify the feasibility of optimizing head shape under cross wind. Compared with the original head-type trains, when there is no cross-wind, the aerodynamic drag of the optimized head-type train is reduced by 2.61% and the aerodynamic lift of the tail-hanger is reduced by 9.90% .2. The aerodynamic drag of the whole vehicle is reduced by 2.98% and the aerodynamic side force of the prime mover is reduced by 0.24%. 3. Under the horizontal wind, the amplitude of the aerodynamic load fluctuation of the head car optimized is reduced.