高速列车通过高海拔大坡度隧道车内外压力波特性

Characteristics of Pressure Wave Inside and Outside High-Speed Train Passing through High-Elevation and Large Gradient Tunnels

为研究高速列车通过高海拔、大坡度和特长隧道下压力波的特性,基于一维可压缩非定常不等熵流动模型的广义黎曼变量特征线法模拟列车通过隧道时的车外压力,采用时间常数法计算车内压力;分别利用国外数值模拟结果和国内西成高铁实车试验数据,验证方法的合理性和准确性;以速度200 km·h^(-1)的单列8编组高速列车为研究对象,分析列车通过4种海拔、5种坡度和4种长度组成的不同隧道时,车内外压力波动和最值的变化规律。结果表明:隧道内初始压力是影响车内外压力幅值的根本原因;车内外最大正、负压均随隧道海拔的升高而线性减小,随隧道坡度和长度的增加而线性增大;与下坡相比,列车上坡运行时车内的压力舒适性更为恶劣、气密性要求更高;列车上、下坡通过坡度30‰、进口端海拔4500 m、长42 km隧道时,车外最大正、负压分别为9.85和-9.63 kPa,列车动态气密时间常数不应小于1713 s。

In order to study the pressure wave characteristics of high-speed trains passing through high-elevation,large gradient and extra-long tunnels,the generalized Riemann variable characteristic line method based on one-dimensional compressible unsteady unequal entropy flow model was used to simulate the external pressures of tunnel-passing trains,and the time constant method was applied to calculate the internal pressures of trains.The rationality and accuracy of the method are verified by the results of numerical simulations abroad and the filed train test data of Xi’an-Chengdu high-speed railway in China respectively.Taking a single 8-carformation high-speed train with a speed of 200 km·h^(-1)as the research object,the variation laws of the pressure fluctuation and the maximum values inside and outside the train were analyzed when the train passes through different tunnels consisting of four elevations,five gradients and four lengths.The results show that the initial pressure inside the tunnel is the essential cause influencing the pressure amplitude inside and outside the train.Both the maximum positive and negative pressure inside and outside the train decrease linearly with the increase of the tunnel elevation,and increase linearly with the increase of the gradient and length of the tunnel.Compared with downhill,the pressure comfort inside the train is worse with higher air tightness requirements while running uphill.When the train passes uphill and downhill through a tunnel with a gradient of 30‰,an elevation of 4,500 m at the entrance,and a length of 42 km,the maximum positive and negative pressure values outside the train are 9.85 kPa and-9.63 kPa respectively,and the dynamic airtight time constant of the train should not be less than 1,713 s.