隧道内高速列车交会时车体两侧压差波动特性数值模拟研究

Numerical Simulation Study on Pressure Difference Fluctuation on Both Sides of Car When High-speed Trains Crossing in Tunnel

列车交会时车体两侧压差影响列车运行稳定性、可靠性和舒适度。基于三维、非定常、可压缩流动的雷诺平均N-S方程和SSTk-ω两方程湍流流动模型,采用重叠网格技术,模拟高速列车在隧道中央等速交会,研究了速度(250km/h、350km/h和400km/h)、线间距(4.6m、4.8m和5.0m)对车体两侧压差波动特性的影响。研究结果表明:车体两侧压差时间历程曲线形状相似于明线交会压力波时间历程曲线形状,在通过列车的车头和车尾经过测点时,压差值分别产生先正后负和先负后正的脉冲波,而且车尾通过时产生的压差明显比车头经过时低;车体两侧最大正压差值、最大负差值以及压差幅值均与速度平方成正比,400km/h下压差最值平均比350km/h大26%,350km/h下压差最值平均比250km/h大92%;车体两侧最大正压差值、最大负差值以及压差幅值均与线间距成负指数关系,压差最值随着线间距变化的增长百分比基本在9%左右。

The pressure difference on both sides of the train affects the stability,reliability and comfort when the train meets. Based on three-dimensional,unsteady Reynolds-averaged N-S equations and SST k-ω two-equation turbulence flow model,the overset mesh technique is used to simulate High-speed train crossing in the middle of a tunnel. The influence of speed (250 km/h,350 km/h and 400 km/h)、track spacing(4.6 m、4.8 m and 5.0 m) on the pressure difference on both sides of the car body was studied. The pressure difference history on both sides of the car body is similar to the shape of crossing pressure wave in open air. When the head and trail passing the measurement points,the pressure difference produces positive first,then negative pulse and first negative,then positive pulse respectively. The pressure difference generated by the tail passes is obviously lower than that when the train passes;The maximum positive pressure difference,the maximum negative pressure difference and the pressure difference amplitude on both sides of the car body are all in direct proportion to the speed square. The maximum value of pressure difference under 400 km/h is 26% larger than that of 350km/h,and the maximum value of pressure difference under 350 km/h is 92% larger than 250 km/h. The maximum positive pressure difference;the maximum negative pressure difference and the pressure difference amplitude on both sides of the car body are all in negative exponential relationship with the track spacing. The maximum value of pressure difference increases with the variation of track spacing basically around 9%.