高速列车隧道交会压力波特性

采用基于有限体积方法的计算流体力学软件, 建立了列车几何模型和非定常可压缩湍流的三维流动模型, 对高速列车隧道内等速和不等速交会的全过程进行了数值模拟。在软件的任意滑移界面动网格技术中嵌入了列车光滑启动方法, 研究了列车交会过程中隧道断面的压力波动、流速变化和压力波的形成过程。研究结果表明: 基于三维流动模型的计算结果能够清晰地展示高速列车隧道内交会时的压力场与速度场变化情况, 同一隧道横截面上各点的压力波动趋势与断面压力均值的波动趋势虽然一致, 但不同测点的压力差异较大, 最大可达53.5%;等速交会时隧道中央的交会压力变化幅值最大, 负压峰值达到约-7kPa; 不等速交会时高速列车车体正压峰值与负压峰值均随低速列车速度的减小而减小, 而低速列车比高速列车的正压峰值大约1.5kPa; 两列车鼻尖交会处的隧道断面压力波负压峰值与低速列车速度的二次方近似成正比。

Crossing pressure wave characteristics of high-speed trains in tunnel

The geometric model of train and 3Dunsteady-compressible turbulence model were set up by using the computational fluid dynamics(CFD)software based on the finite volume method(FVM), and the whole crossing processes of high-speed trains were simulated in constant-speed and variable-speed conditions.The smooth starting method was coupled into the moving mesh technique of arbitrary sliding interface(ASI)to study the pressure fluctuation characteristics, the air velocity varition and the forming processes of pressure waves at tunnel sections in the whole crossing processes.Study result shows that the pressure fields and velocity fields in high-speed trains passing process in tunnel are clearly depicted via the 3Dfluid flow model.Though the pressure fluctuation trends of monitoring points at a tunnel cross section are consistent with that of cross-section average pressure, the pressure differences of monitoring points are considerably high, and the maximal difference is 53.5%.The pressure fluctuation amplitude at the middle section of tunnel is largest in constant-speed crossing, and the negative pressure peak value is about-7kPa.In constant-speed crossing, when the speed of lower-speed train decreases, the peak values of positive and negative pressures for higher-speed train decrease, while the positive pressure peak value of lower-speed train is about 1.5kPa higher than that of higher-speed train.The negative pressure peak value at the cross section where two train noses meet together isproximately direct proportional to the speed square of lower-speed train.