重联动车组通过隧道时气动性能研究

Study on the aerodynamic performance of a couple multiple units high-speed train entering into a tunnel

为研究重联动车组通过隧道时重联区域对列车气动性能的影响,采用三维、可压和非定常N-S方程的数值计算方法,对重联动车组通过隧道时压缩波与膨胀波的传播特性,列车表面压力和隧道壁面压力变化特性进行研究。研究结果表明:数值计算与动模型试验相比,压力变化曲线吻合较好,幅值偏差不超过7%,重联区域前段流线型头部进入隧道,产生膨胀波,重联区域后段流线型头部进入隧道,产生压缩波,由于重联区域产生的膨胀波和压缩波之间的时间间隔短,导致膨胀效应和压缩效应相互抵消,车体表面和隧道壁面压力变化不显著,当重联区域经过隧道壁面测点时,重联区域车体表面压力变化影响隧道壁面压力变化,使隧道壁面测点压力产生先升后降的波动。

In order to study how the coupling region affects aerodynamic performance of the couple multiple units trains when they go through a tunnel,based on unsteady N-S equation of three-dimensional and compressible viscous fluid,transient pressure propagation over time and the pressure on the vehicle body and tunnel were simulated.The results show that the calculated results agree with those of the experimental model.The switch of pressure curves attained by two methods are accorded completely,and amplitude merely presented difference is only about 7%.When the first streamline head on coupling region entering into a tunnel,the expansion wave occurred.When the second streamline head on coupling region entering into a tunnel,the compression wave occurred.Due to the short time interval between the expansion wave and the compression wave generated in coupling region,the effect of expansion and compression cancel out,and the pressure on the vehicle body surface and the tunnel wall surface is insignificant.When the coupling region passing through the monitor point of the tunnel wall,the pressure change on surface of the vehicle body surface effect the pressure change on tunnel wall,so the pressure of monitor point on tunnel wall lead fluctuation of first rising and last declining.