Effect of simplifying bogie regions on aerodynamic performance of high-speed train

Abstract

An investigation of the effect of simplifying bogie regions on the aerodynamic performance of a high-speed train was carried out by studying four train models, to explore possible ways to optimise the train underbody structure, improve the underbody aerodynamic performance, and reduce the aerodynamic drag. The shear stress transport (SST) k−ω turbulence model was used to study the airflow features of the high-speed train with different bogie regions at Re=2.25×10⁶. The calculated aerodynamic drag and surface pressure were compared with the experimental benchmark of wind tunnel tests. The results show that the SST k−ω model presents high accuracy in predicting the flow fields around the train, and the numerical results closely agree with the experimental data. Compared with the train with simplified bogies, the aerodynamic drag of the train with a smooth surface and the train with enclosed bogie cavities/inter-carriage gaps decreases by 38.2% and 30.3%, respectively, while it increases by 10.8% for the train with cavities but no bogies. Thus, enclosing bogie cavities shows a good capability of aerodynamic drag reduction for a new generation of high-speed trains.

摘要

为探究列车底部转向架区域结构对列车底部流场以及列车气动性能的影响,本文采用SST k−ω湍流模型对不同简化程度转向架、雷诺数Re=2.25×10⁶下的三车编组高速列车周围流场进行仿真分析,并结合风洞试验结果验证数值方法的正确性。分析结果表明:与原始带转向架的列车模型相比,移除转向架并光顺列车车身的简化模型,可实现列车减阻38.2%; 将转向架区域进行全包裹并光顺风挡区域,列车气动阻力减少30.3%; 而当移除转向架并保留转向架腔外形时,列车气动阻力不减反增10.2%。因此,在进行高速列车气动外形减阻设计时,可考虑封闭转向架腔的方式,实现列车整车气动减阻。