川藏铁路隧道长度对动车组通过隧道压力波的影响

Influence of Sichuan-Tibet Railway Tunnel Length on Pressure Wave of EMU Train Passing through Tunnels

为研究川藏铁路隧道长度对动车组通过隧道时压力波的影响,采用一维可压缩非定常不等熵流动模型和广义黎曼变量特征线法,对列车在上坡或下坡隧道内运行时车外压力波进行数值计算,得到列车通过不同长度隧道时头尾车压力波特性。详细分析隧道长度对列车通过隧道时头尾车压力波峰值的影响规律。结果表明,列车上坡通过隧道时,隧道长度超过1km后头车最大正压值基本保持不变,隧道长度对尾车最大正压值影响较小;头尾车最大负压幅值和最大压力峰峰值随隧道长度增加而增大,且隧道长度超过4 km后呈线性增大趋势;列车下坡通过隧道时,头尾车最大正压值和最大压力峰峰值基本随隧道长度的增加而增大,且隧道长度超过4km后呈线性增大趋势;头尾车最大负压幅值随隧道长度增加先增大后减小,隧道长度超过20 km后,头尾车最大负压值基本保持不变。研究结果可为川藏铁路动车组气密性及乘客压力舒适度设计提供参考。

To study the influence of the Sichuan-Tibet railway tunnel length on the pressure wave of the EMU train passing through tunnels,the one-dimensional compressible unsteady non-homentropic flow model and the method of characteristics of generalized Riemann variables are used to numerically calculate the external pressure wave of the train travelling in the uphill or downhill tunnel.The pressure wave characteristics of the head coach and the tail coach of the train passing through tunnels with different lengths are obtained.The influence law of the tunnel length on the peak values of the pressure wave of the train passing through tunnels is analyzed in detail.Results show that for the train travelling in the uphill tunnel,the maximum positive pressure of the head coach basically keeps unchanged when the tunnel length exceeds 1 km.The tunnel length has less effect on the maximum positive pressure of the tail coach.The maximum negative pressure amplitudes and the maximum peak-to-peak pressures of the head coach and the tail coach increase with the tunnel length,and the increase tends to be linear when the tunnel length exceeds 4 km.For the train travelling in the downhill tunnel,the maximum positive pressures and the maximum peak-to-peak pressures of the head coach and the tail coach basically increase with the tunnel length,and the increase tends to be linear when the tunnel length exceeds 4 km.The maximum negative pressure amplitudes of the head coach and the tail coach firstly increase and then decrease with the tunnel length.When the tunnel length exceeds 20km,the maximum negative pressures of the head coach and the tail coach basically keep unchanged.The results can provide a reference for the design of the airtightness and the passenger pressure comfort of the Sichuan-Tibet railway EMU train.