城际列车梳齿状涡流发生器气动减阻研究

Study on Aerodynamic Drag Reduction Optimization of Intercity Trains with Comb-like Vortex Generators

为减小钝体头型城际动车组的气动阻力,开展尾车车体与头型变截面区处梳齿状涡流发生器气动减阻效应研究。针对保留底部转向架基本气动外形的头车-中间车-尾车列车简化模型,采用Realizable k-ε湍流模型研究梳齿状涡流发生器对列车尾部流动分离以及整车气动阻力的影响。结果表明:钝头城际列车尾部存在明显流动分离现象,同时伴随涡旋产生、发展与脱落。在列车尾部车体末端安装涡流发生器后,气流分离被有效延缓,涡旋产生与发展得到明显抑制,列车尾部流场结构显著优化。对列车进行气动力分析发现,在60 m/s速度下,安装涡流发生器后,尾车压差阻力降低22.07%,三车模型气动总阻力降低7.15%,可以有效减少城际列车碳排放。

To reduce the aerodynamic drag of a bluff head intercity EMU train,a comb-like vortex generator was used to reduce the aerodynamic drag of a typical intercity EMU train in the transition area between the tail car body and head.Based on the simplified head car-middle car-tail car train model that retains the basic aerodynamic shape of the bogie,the influence of a comb-like vortex generator on the flow separation at the tail of the train and the aerodynamic drag of the whole train was studied by using the Realizable k-εturbulence model.The results show that there is an obvious flow separation at the tail of the bluff head intercity train,accompanied by the generation,development and shedding of vortices.The installation of a vortex generator at the tail of the car body can effectively delay the flow separation,and significanly inhibit the generation and development of the vortex,which optimizes the flow field structure at the tail of the train.According to the aerodynamic analysis of the train,at the speed of 60 m/s,the pressure drag of the tail car is reduced by 22.07%and the aerodynamic drag of the whole train is reduced by 7.15%after the installation of the vortex generator,which can effectively reduce the carbon emissions of intercity trains.