时速160公里城际列车气动性能研究

Aerodynamic performance for inter-city trains at a speed of 160 km/h

随着国内高速铁路网不断完善、城市内部和城际之间的轨道交通快速发展,城际列车设计速度逐年提高,达到160 km/h,其在运行过程中将面临一系列空气动力学问题。为分析160 km/h城际列车运行时的综合气动性能,利用STAR CCM+软件,采用三维雷诺时均Realizable k-ε湍流模型模拟城际列车的周围流场特性,应用重叠网格模拟列车穿越隧道的滑移运动,将原始头型、改进头型和车顶设备城际列车模型进行数值仿真分析,研究160 km/h城际列车明线运行和通过2种不同横截面积隧道时的流场特性和车体的受力情况,分析城际列车在不同工况下的气动性能。研究结果表明:适用于干线铁路160 km/h城际列车的头车气动阻力较大,通过改进头车的凹槽外形和空调导流斜面,可减少头车所受气动阻力,头车的阻力系数由0.397减小为0.349,降幅12%,整车减少8.26%。横风条件下,头车车身阻力系数随风向角的增大而减小,中间车和尾车的车体阻力系数随着风向角增大而增大,头车倾覆力矩系数最大,沿车身方向降低,尾车最小。城际列车以相同速度通过50 m^(2)和80 m^(2)隧道时,改进模型表面压力降低,且采用较大隧道截面面积时,列车所受压缩波和膨胀波的影响更小,运行品质更高。

With the continuous improvement of the domestic high-speed railway network,the rail transit within and between cities is also developing gradually.The design speed of intercity trains is increasing year by year,reaching 160 km/h.There are problems of aerodynamic performance of inter-city trains in open line,intersection and tunnels.To discuss the comprehensive aerodynamic performance of intercity trains with a speed of 160 km/h,Star CCM+software,with three-dimensional Reynolds-averaged Navier-Stokes equations and Realizable k-εturbulence model,was used to simulate the flow field characteristics around the intercity train.The overlapping grid method was adopted to realize the sliding motion of the train passing through the tunnel.The original and the improved intercity train model with head and roof equipment were numerically simulated and analyzed.The flow field characteristics and the loads of the intercity trains,when running in open air with a speed of 160 km/h and passing through a tunnel with different cross-sectional areas,were studied.The aerodynamic performance of the intercity train under different working conditions was analyzed.The results show that the aerodynamic resistance of the head car of the intercity train with a speed of 160 km/h suitable for the trunk railway is large.The aerodynamic resistance of the head car can be reduced by improving the slot shape of the head car and the air conditioning diversion slope.The resistance coefficient of the head car can be reduced from 0.397 to 0.349,a decrease of 12%and the whole vehicle can be reduced by 8.26%.Under the cross-wind condition,the body resistance coefficient of the head car decreases with the increase of the wind direction angle,the body resistance coefficient of the middle car and the tail car increases with the increase of the wind direction angle.The overturning moment coefficient of the head car is the largest,decreases along the body direction,and the tail car is the smallest.When passing through 50 m2 and 80 m2 tunnels at the same speed,the surface pressure of the improved model decreases,and when a larger tunnel cross-section area is adopted,the intercity train is less affected by compression wave and expansion wave,and the operation quality is higher.