U型轨道侧轨高度对超导磁浮列车气动特性的影响

Effect of U-track Side Track Height on the Aerodynamic Characteristics of Maglev Trains

为研究U型轨道侧轨高度对超导磁浮列车的气动特性的影响,本文采用三维、非定常Realizable k-ε湍流模型,对超导磁悬浮列车的气动特性进行数值仿真和分析.研究结果表明,U型轨道侧轨高度的增加对头、尾车影响较大,对中间车影响较小.随着U型轨道侧轨高度的增加,头、尾车流线型区域负压区面积和负压值逐渐增大,致使其气动阻力增大;头车气动升力随侧轨高度的增加呈现出逐渐增大的趋势,尾车气动升力绝对值则随侧轨高度先增大后减小,当侧轨高度为1.8 m时的气动升力绝对值最小.在横风作用下,随着U型轨道侧轨高度的增加,列车两侧的压差逐渐减小,当侧轨高度为1.8 m时,侧向力绝对值最小,随后随着侧轨高度的增加,侧向力反向,列车可能出现反向倾覆的危险.因此,综合列车无风和横风环境下的气动载荷分析,1.8 m侧轨高度最优,本文结果可为U型轨道设计提供理论依据.

In order to study on the influence of U-type side track height on the aerodynamic characteristics of superconducting maglev trains,this paper adopts a three-dimensional and unsteady Realizable k-eturbulence model to emulate and analyze the aerodynamic characteristics of superconducting maglev trains.The research results show that the side track height of the U-type rail has significant impact on the head and tail cars but minimal impact on the middle car.As the side track height of the U-type rail increases,the area and value of the negative pressure distributed on the head and tail car increase,resulting in an increase in the aerodynamic drag.The aerodynamic lift of the head car shows a trend of gradual increase with the increase of the side track height.However,the absolute value of the aerodynamic lift of the tail car initially increases then followed by a decrease,with its minimum value at a side track height of 1.8 m.Under the impact of cross wind,the pressure difference between the two sides of the train gradually decreases with the increase of the side track height of the U-type rail.the absolute value of the lateral force reaches its minimum when the height of the side track is 1.8 m,then it increases with the increase of the height and changes in the reverse direction,the train is in danger of overturning in the windward direction.Based on the aerodynamic load analysis of the train without and under crosswind conditions,a side track height of 1.8 m is optimal,which provides basis for the design of U-type rail.