市域列车隧道断面突变位置气动特性

Aerodynamic Characteristics of City Railway Train at the Sudden Variable Tunnel Cross-Section Positions

[目的]为了确保列车运营安全性与旅客乘坐舒适性,需研究市域列车过隧道内变截面位置(进站台、隧道内运行、过中间风井)时的气动力和车内压力变化规律。[方法]以8节编组的市域列车为例,建立数值计算模型;开展隧道变截面处气动性能数值仿真研究,分别对列车车体表面压力、隧道壁面压力、列车气动力、车内压力变化情况进行分析。[结果及结论]列车车体表面压力、气动载荷的变化规律为:列车进站时的表面压力和横向力>列车经过中间风井时的表面压力和横向力>列车在隧道内运行时的表面压力和横向力。车体表面压力幅值与列车运行速度的1.4~2.0次方呈线性关系;隧道壁面压力与列车运行速度的1.79~2.10次方呈线性关系;车体横向力与列车运行速度的1.8~2.0次方呈线性关系,倾覆力矩与列车运行速度的1.6~2.0次方呈线性关系。市域列车气密性设计能满足隧道内变截面位置处,车内压力变化不大于每3 s内压力变化800 Pa和每1 s内压力变化500 Pa的人体舒适性标准要求。

[Objective]In order to ensure train operation safety and passenger comfort,it is necessary to study the chang-ing laws of aerodynamic force and pressure inside the city railway train when passing through the variable cross-section positions in the tunnel(entering the platform,running in the tunnel,and passing through the intermediate air shaft).[Method]Taking the 8-carriage city railway train as an example,a numerical calculation model is established.A numerical simulation study on the aerodynamic performance at the variable tunnel cross-section is carried out,and the changes in the train body surface pressure,tunnel wall pressure,train aerodynamic force,and pressure inside the train are analyzed respectively.[Result&Conclusion]The changing laws of train body surface pressure and aerodynamic load are as follows:the surface pressure and lateral force with train entering the station>the surface pressure and lateral force with train passing through the intermediate air shaft>the surface pressure and lateral force when the train runs into the tunnel.The train body surface pressure amplitude is linearly related to the 1.4~2.0 power of the train running speed;the tunnel wall pressure is linearly related to the 1.79~2.10 power of the train running speed;the train body lateral force is linearly related to the 1.8~2.0 power of the train running speed,and the overturning moment is linearly related to the 1.6~2.0 power of the train running speed.The air-tightness design of the city railway train can meet the human comfort standard requirements,namely the pressure change inside the car at the variable tunnel cross-section positions shall not exceed 800 Pa per 3 seconds and 500 Pa per 1 second.