基于一维流动模型的高速列车隧道交会空气阻力数值模拟研究

应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,考虑列车交会诱发的空气压力和流速变化,提出高速列车隧道交会空气阻力的计算方法。研究中国标准动车组CR400AF隧道交会列车空气阻力变化规律,分析列车交会位置、隧道长度、阻塞比、列车运行速度和列车长度对列车空气阻力的影响。结果表明:在研究隧道内列车空气阻力和列车周围气流流动时必须考虑压缩波和膨胀波的传播方向,交会位置对平均列车空气阻力的影响较小;在隧道中央等速交会时,列车空气阻力随隧道长度、阻塞比和车速增大而增大,且这3者的影响程度依次增大;平均列车空气阻力与车速的2次方近似成正比,与阻塞比的0.67～0.75次方成正比,与隧道长度的0.01次方成正比;时速300～400km等级16辆编组高速列车的平均列车空气阻力约为8辆编组的1.65～1.70倍。

Numerical Simulation on Air Resistance of High Speed Trains Crossing in Tunnel Based on One-Dimensional Flow Model

Based on one-dimensional compressible unsteady non-homoentropic flow model and the generalized Riemann variable characteristic line method,the calculation method for the air resistance of high speed trains crossing in tunnel was proposed considering the variations of air pressure and flow velocity induced by trains.The variations of the air resistance of two CR400AF,the standard EMUs in China,crossing in the tunnel,were studied.The effects of train crossing position,tunnel length,blockage ratio,running speed and train length on the air resistance of train were analyzed.Results show that the propagation directions of compression wave and the expansion wave must be considered when studying the air resistance of train and the air flow around train in tunnel.The crossing position has little influence on the average air resistance of train.When two trains crossing in the center of tunnel with the same speed,the air resistance of train increases with the increase of tunnel length,blockage ratio,and train speed,and the influence degrees of these three factors increase in order.The average train air resistance is approximately proportional to the second power of train speed,0.67~0.75 power of blocking ratio and 0.01 power of tunnel length.The average air resistance of a 16-car formation high speed train at the speed of 300~400 km·^-1 is about 1.65~1.70 times of an 8 car formation train.