高速磁悬浮列车编组长度对车/隧耦合气动效应的影响

Influence of marshalling length of high-speed maglev train on vehicle/tunnel coupling aerodynamic effect

采用重叠网格法,基于SST k-ω两方程的DDES湍流模型,研究编组长度对高速磁悬浮列车/隧道耦合气动特性的影响。采用动模型试验结果对数值仿真方法进行验证,将3车编组的动模型试验所得测点压力与相同编组的仿真试验所得测点压力进行对比。分析3车编组高速磁浮列车以速度500、550和600 km/h通过隧道时车体表面、隧道壁面压力变化基本规律,在此基础上研究3车编组、5车编组和8车编组形式对高速磁浮列车/隧道气动特性的影响,并绘制瞬变压力波系传播的马赫波图,揭示编组长度导致测点压力变化差异的原因,得到高速磁浮列车编组长度对隧道出口微气压波的影响规律。研究结果表明:高速磁浮列车表面、隧道壁面压力幅值与车速呈正相关关系;当编组长度增加时,车/隧表面的压力随时间的变化趋势基本一致,但正、负压幅值及压力峰峰值明显增大:当磁悬浮列车以速度550 km/h通过长度为500 m、截面积为140 m^(2)的隧道时,5车编组与8车编组的车体表面最大压力峰峰值比3车编组分别增加12.4%和8.5%,隧道表面最大压力峰峰值比3车编组分别增加49.6%和38.9%,因此,在隧道长度一定时存在最不利的编组长度;磁悬浮列车编组长度对无缓冲结构隧道出口微气压波幅值影响较小。

Based on the DDES turbulence model of SST k−ωequation,the overlapping grid method was used to explore the influence of marshalling length on the coupled aerodynamic characteristics of high-speed maglev train/tunnel.The numerical simulation method was verified by using dynamic model test results,and the pressure at the measuring points obtained from the dynamic model test of a 3-cars marshalling was compared with the pressure at the measuring points obtained from the simulation experiment of the same formation.The basic law of the pressure changes on the car body surface and tunnel wall was analyzed when 3-cars marshalling high-speed maglev trains passed through the tunnel at speeds of 500,550 and 600 km/h.On this basis,the influence of different marshalling forms of 3-cars,5-cars and 8-cars on the aerodynamic characteristics of high-speed maglev trains/tunnels was studied.The Mach wave diagram of transient pressure wave system propagation was drawn,revealing the principle that marshalling length leads to the pressure changes at the measuring point,and obtaining the influence law of marshalling lengths of high-speed maglev trains.The results show that there is a positive correlation between the pressure amplitude on the surface of high-speed maglev train and the tunnel wall and the speed.With the increase of marshalling length,the fluctuation trend of the pressure on the car/tunnel surface with time is basically the same,but the positive and negative pressure amplitudes and pressure peaks increase obviously.Compared with the 3-cars marshalling,when the maglev train passes through a tunnel with a length of 500 m and a cross-sectional area of 140 m^(2)at a speed of 550 km/h,the maximum pressure peaks on the car body surface of 5-cars marshalling and 8 cars marshalling increase by 12.4%and 8.5%,respectively,and the maximum pressure peaks on the tunnel surface increase by 49.6%and 38.9%,respectively.Therefore,there exists the most unfavorable marshalling length when the tunnel length is constant.The length of maglev train marshalling has little influence on the amplitude of micro-pressure at the exit of tunnel without buffer structure.