高速列车进入带缓冲结构隧道的压力变化研究(Ⅰ)

给出了列车穿越带有缓冲结构的隧道压力变化的三维粘性流场数值模拟过程,控制方程为三维粘性、可压缩、非定常流的N-S方程,空间离散采用了中心有限体积法格式,时间采用预处理二阶精度多步后差分格式进行离散,对列车与隧道之间的相对运动采用移动网格技术处理。对不同的缓冲结构缓解隧道内瞬变压力及压力梯度的作用进行了研究。研究结果表明,缓冲结构的设置能够有效地降低隧道内的压力和压力梯度的最大值,其原因在于缓冲结构延长了压缩波压力上升的时间,降低列车突入隧道时所形成的最大压力梯度;另一方面由于压缩波在缓冲结构和列车、隧道之间多次的反射,也降低了压力峰值。

Study on the compression wave induced by a high-speed train entering into a tunnel with hood (Ⅰ)

A cell-centered finite volume scheme for numerical integration of Navier-Stokes equations has been presented here for three-dimensional unsteady viscous compressible flow to simulate the compression wave produced by a train passing through tunnel with hood.The numerical procedure is based on pre-conditioned second-order accurate backward difference in time,the relative motion between the train and tunnel treated with sliding mesh technique.The paper studies on the effect of hoods for the compression wave and compression grade.The hood can effectively decrease the maximum pressure gradient because of delaying the time of the pressure rise time.On the other hand,the compression wave is reflected among the hood,the train and the tunnel.It can also decrease the amplitude of the compression wave.