动车组明线运行空气动力学数值仿真

通过采用不可压缩粘性流体的N-S方程和K-ε双方程湍流模型,建立了带有车轮的200 km/h动车组模型,对其明线运行的外流场进行了空气动力学仿真.并对列车壁面附面层网格进行了细分,得出压力、速度的分布规律,针对网格划分对计算结果的影响进行了探讨.得出如下结论：列车的阻力系数为0.436,升力系数为0.014;此型200 km/h动车组车尾的安全避让距离为6 m;当加密附面层网格使y＋从2200减小到55时,阻力系数提高15%.

Aerodynamic Simulation of External Flow of Multiple Units Running in Open Air

Using N-S equation of uncompressible viscosity fluid and K-ε turbulence model,the model of multiple units with wheels is constructed,and a simulation is conducted on external flow of 200km/h multiple units.Meanwhile,a refinement is taken on the boundary layer mesh of train surface to obtain the distribution of pressure and velocity,and an analysis is also made on the mesh partition to the results.The study shows that the train resistance coefficient and lift coefficient are 0.436 and 0.014 respectively.The safety distance from the rear of the train is 6 meters,and the drag coefficient increases by 15% when y＋ reduces to 55 from 2200 by refining the boundary layer grid.