高速列车过双线隧道气动效应及列车风特性

Aerodynamic effects and train wind characteristics of high-speed train passing through double-track tunnel

摘要:

为加深对隧道内气动效应和列车风特性的认识,采用RNG κ-ε湍流模型模拟高速列车偏心通过隧道全过程,应用滑移网格技术模拟列车高速运动,对列车通过时隧道内的气动效应及列车风进行研究。通过将数值计算结果与现场试验结果进行对比,验证了数值方法的准确性。研究表明:隧道入口处气动压力变化规律与隧道内有很大差别；列车两侧对称测点的最大正压值及峰-峰压力变化幅值分别相差13.1%和7.3%,近隧道侧列车风纵向速度分量与合速度最大值分别为远隧道侧的2.1倍和1.9倍,列车偏心通过对列车周围气动压力影响不大,而对列车风影响非常显著；列车表面边界层对列车风纵向分量影响显著,对横向速度分量和垂向速度分量几乎无影响；隧道内列车后方产生交替出现的复杂尾涡结构,与明线时差别很大；隧道内列车风风速衰减较慢,持续时间更久。

Abstract:

To further understand the aerodynamic effects and the characteristics of train wind, the RNG κ-ε model was used to simulate the overall process of a high-speed train passing through a tunnel asymmetrically. The movement of the train was simulated using the sliding mesh technique. The aerodynamic effects and the train wind characteristics were investigated, and the accuracy of the numerical method was verified by comparing the numerical results with the results of a full-scale experiment. Results show that there was a large difference of pressure transients between the entrance and inside of the tunnel. The maximum positive pressures and the peak-peak pressure transients amplitude differed by 13.1% and 7.3% at the symmetrical monitoring points on both sides of the train. The longitudinal velocity component and the maximum resultant velocity on the near-tunnel side were 2.1 and 1.9 times those of the far-tunnel side respectively. The train passing asymmetrically had no obvious effect on the aerodynamic pressure, but the impact on the train wind was significant. The boundary layer of the train had a significant effect on the longitudinal component of the train wind, while the effect on the lateral velocity component and the vertical velocity component was small. Complex wake vortex structures alternately appeared behind the tail, which was very different in the open air. The attenuation of the train wind velocity in the tunnel was slower, and the duration was longer.