风屏障开孔形式对车桥系统气动特性影响的数值研究

采用流体力学软件（Star CCM+）建立32 m简支箱梁和CRH2型高速列车的全尺寸模型，对不同风屏障开孔形式的车桥系统进行数值模拟，研究了风屏障开孔形式对风屏障挡风效率和流场的影响，分析了车辆三分力系数和桥梁三分力系数随开孔形式的变化规律。结果表明：风屏障的开孔形式对车辆的阻力系数影响较大，且随着开孔边数的增加各车辆的阻力系数先减小后增大，开孔形式为格栅形时阻力系数最大。采用格栅形式时中车比头车的力矩系数大了63.6%；中车的阻力系数和力矩系数随开孔边数的增加基本呈下降趋势，位于背风侧时中车阻力系数和力矩系数变化较缓；随着风屏障开孔边数的增加，桥A段、桥B段和桥C段的CRWBD都呈增加趋势，其中桥B段的贡献率增加地最多，增加了12.2%。风屏障对阻力和力矩的贡献率CRWBD、CRWBM基本都超过了50%。

Numerical Study on the Influence of Wind Barrier Hole Type on the Aerodynamic Characteristics of Vehicle-Bridge System

The fluid mechanics software (Star CCM+) is used to establish a full-scale model of a 32 m simply supported box girder and a CRH2 high-speed train. Numerical simulations of the vehicle-bridge system with different wind barrier openings are carried out, and the effect of the wind barrier openings on the wind barrier is studied. The influence of windshield efficiency and flow field is analyzed, and the three-component force coefficient of vehicle and bridge three-component force coefficient with the opening pattern are analyzed. The results indicate that, the opening form of the wind barrier has a greater impact on the drag coefficient of the vehicle, and the drag coefficient of each vehicle first decreases and then increases with the increase of the number of opening sides. The drag coefficient is the largest when the opening form is grid-shaped. When the grille is adopted, the drag coefficient of the middle car is 63.6% larger than that of the head car. The drag coefficient and moment coefficient of the middle car basically show a downward trend with the increase of the number of openings, and it changes slowly when they are on the leeward side. With the increase in the number of openings of the wind barrier, the CRWBD of the bridge A, the bridge B and the bridge C showed an increasing trend, and the contribution rate of the bridge B increased the most, an increase of 12.2%. The contribution rate of the wind barrier to the drag force and moment is basically more than 50% in CRWBD and CRWBM.