铁路隧道出口微压波问题的数值模拟

Numerical Investigation of Micro Pressure Wave Radiated from the Exit of a Railway Tunnel

采用有限体积法和TVD性质的差分格式相结合求解轴对称欧拉方程的方法对高速列车通过隧道时在隧道出口区域产生的微压波问题进行了数值研究.通过该数值方法计算得到的结果和国外试验量测结果符合良好,表明该方法能够比较精确地模拟这一现象.通过该数值方法对相关影响因素进行了研究.研究结果表明,隧道出口处挡板的位置和直径大小对于微压波压力峰值的空间分布具有重要影响.文中针对到达隧道出口附近的压缩波为弱冲击波的情况,给出了隧道出口处设无限大挡板和不设挡板时微压波压力峰值的空间分布图.文中提出了用于计算出隧道出口处微压波的压力峰值的公式.该公式表明,微压波的压力峰值与测点到隧道出口中心之间的距离以及测点与隧道出口中心之间的连线和隧道轴线所形成的夹角密切相关.文中的研究结论和方法可为制定微压波减缓措施提供重要依据.

The finited volume method and a total variation diminishing（TVD）numerical scheme were used to solve the axisymmetric Euler equation,which was utilized to simulate the Micro Pressure Wave discharged from the tunnel exit when a train entered a tunnel at high speed. The results from numerical calculation and foreign experiments agreed well, which can presume that the numerical method can well simulate the micro-pressure wave. With the help of the numerical method, related influence factors are investigated. The results make it clear that the size and position of the baffle at the tunnel exit importantly influence space distribution of the maximum pressure of micro-pressure wave. In addition, the figures of the isobars of the maximum pressure of the micro-pressure wave are given with a infinite baffle and without the baffle at the tunnel exit when the coming compression wave is a weak shock wave. The formulae calculating the maximum pressure of micro-pressure wave are given which show the maximum pressure is related close with the distance from the measured point to the tunnel exit center and the angle between the tunnel axis and the line from the measured point to the tunnel exit center. The research results and method will provide important references for the design of Micro Pressure Wave alleviation measure.