160 km/h地铁列车头型气动阻力优化

采用三维、瞬态、可压缩N-S方程和k-湍流模型及滑移网格技术的数值仿真方法，研究隧道内地铁列车头型几何参数对列车气动阻力的影响规律及气动阻力对头型几何参数的敏感性.对80 km/h地铁列车头型进行气动阻力优化，获取160 km/h优化模型.结果表明：当阻塞比约为0.45时，隧道气动阻力是明线的3倍；当头型长度L ≤ 5 m时，气动阻力与头型长度符合对数关系，综合考虑敏感性与气动阻力，头型长度选择3.0~4.0 m较合适；车体横截面积对列车气动阻力的影响较大，且灵敏度很高，可以适当减小横截面积，以降低列车气动阻力；当头型长度L=3 m时，考虑气动阻力及敏感性，俯视轮廓线等效长度选为（2.68±0.01） m，纵向轮廓线等效长度选为（2.32±0.005） m较合适.通过参数研究，优化后的列车模型在明线工况下整车气动阻力下降3.7%.
Abstract: The influence of the head parameters on the aerodynamic drag and the sensitivity of the aerodynamic drag to the head parameters were analyzed based on N-S equation of the compressible viscous fluid, k- turbulence model and the sliding mesh technique in order to optimize the aerodynamic drag of the 80 km/h subway train. The calculation results show that the aerodynamic drag in the tunnel is three times of the aerodynamic drag in the open field at the blocking ratio about 0.45. When the head length is less than or equal to 5 meters, the aerodynamic drag is in logarithmic relation with the head length. The length of the head is chosen between 3 and 4 meters after a systematic consideration. The cross-sectional area can be appropriately reduced in order to reduce the aerodynamic resistance, because the cross-sectional area has greater impact on the train aerodynamic drag and aerodynamic resistance on the cross-street area sensitivity is high. Considering the aerodynamic drag and sensitivity, the equivalent length of the contour line is (2.68±0.01) m and the equivalent length of longitudinal contour is (2.32±0.005) m when the head length is 3 m. The aerodynamic drag of the 160 km/h optimized train model was reduced by 3.7% under open field compared to the original model.