低真空管道交通系统列车气动阻力研究

Train Aerodynamic Resistance in Transportation System of Low Vacuum Tube

采用计算流体动力学软件,结合动网格技术,建立全长200 m的8节全尺寸列车模型,基于三维瞬态可压缩黏性流体数值模拟,分析低真空管道交通系统列车的气动阻力分布规律,以及真空度、阻塞比、管道截面形状、列车运行速度等因素与列车气动阻力的关系。研究表明,列车气动阻力主要由头车和尾车产生,中间各节车气动阻力不同但均占比不大,气动阻力成分主要为压差阻力,且远大于摩擦阻力;列车气动阻力随真空度、阻塞比增大而增大,且均近似成线性关系;在同阻塞比情况下,方形截面管道内列车气动阻力大于半圆形截面管道内列车气动阻力;在低真空管道环境下,列车气动阻力与速度近似为二次关系。

This paper adopts computational fluid dynamics software and dynamic grid technology to establish a full-scale train of 8 cars with a total length of 200 m.Based on three-dimensional transient compressible viscous fluid,the distribution law of aerodynamic resistance of train in low vacuum tube transportation system is analyzed,as well as the relationship between aerodynamic resistance of train and various factors such as vacuum degree,blockage ratio,tube section shape,train running speed,etc.The result shows that the aerodynamic resistance of train is mainly generated by the head car and tail car,and is different among cars in the middle but does not account for a large proportion.The aerodynamic resistance component is mainly differential pressure resistance,which is far greater than frictional resistance;the aerodynamic resistance of train increases with the increase of vacuum degree and blockage ratio,which are approximately linear;under the same blockage ratio,the aerodynamic resistance of train in square tube section is greater than that in semi-circular tube section;in the low vacuum tube environment,the aerodynamic resistance of train is approximately quadratic with speed.