高速铁路隧道内气动压力波的变形规律研究

Study on deformation law of aerodynamic pressure wave in high speed railway tunnel

通过理论分析及数值模拟方法,对高速列车进入隧道产生的压缩波的波形变化及衰减规律进行了研究。研究结果表明,压缩波在隧道内向前传播时,在隧道某一横断面上,距离列车越近的点其压力越大,越远则最大压力值则越小,但整体上各个点的最大压力值相差较小,基本上可以认为压缩波在隧道内向隧道出口方向传播时是以平面波的形式向前传播的。其次,在隧道纵向上,平面压缩波在隧道内向前传播时,其波形曲线发生变化,表现为波的最大压力峰值及波形曲线压力梯度发生变化。分析认为,由于隧道壁面、列车壁面的摩擦、空气的粘滞作用耗散了空气压缩波的能量,而板式道床及碎石道床能够,均可导致压缩波波前发生衰减,同时,压缩波向隧道前方传播时,由于波的非线性效应,导致压缩波的波前变陡,其主要影响因素是声波雷诺数。

Through theoretical analysis and numerical simulation, the waveform change and attenuation law of compressional wave generated by high-speed train entering tunnel are studied. The results show that in the process of compression wave moved forward in the tunnel,the point near the train where pressure is higher,rather the point far is lower but the maximum pressure of each point is small from overall point of view,so it is basically considered that the compression wave moved forward in the form of plane wave in the tunnel exit direction. Next,the planar compression wave moves forward in the tunnel within the episode broadcast,the waveform changes,that is wave-front peak pressure and pressure wave front gradient changes. Analysts believe that it can lead to compression wave attenuation for some reasons,the frictional resistance of tunnel wall and train surface,also the viscous effect of air and ballast structure type;at the same time,the compression wave spread to the front of the tunnel,it is resulted that wave-front peak of the compression wave is steepened,due to nonlinear effects in the wave,and the main influencing factor is the acoustic Reynolds number.