风屏障对桥梁及车桥系统气动特性影响的数值研究

The numerical simulation method was used to study the effects of wind barrier parameters(porosity rate and height) on aerodynamic characteristics of streamlined bridges. The influence of wind barriers on aerodynamic characteristics of different bridge types was systematically analyzed and compared laterally, and in addition, the influence of wind barriers on aerodynamic characteristics of train-bridge system and its flow field were discussed, the potential mechanism of wind barrier on the aerodynamic performance train-bridge system was revealed by analysing the characteristics of three-component force coefficient, pressure contour, velocity flow field, wind pressure distribution and wind profile. The results show that the wind barrier can reduce drag force and lift moment on the train, but also significantly increase the drag force of the girder since it declines the average flow velocity above the main beam.Therefore, the installation of wind barriers can improve the driving safety of the train but can be harmful for the wind resistance of the bridge. The optimal combination of wind barrier for streamlined bridge-deck section is 3 m with porosity rate of 30% since the drag force coefficient reaches the minimum value 1.33 in this case. The sheltering effect of wind barrier is different for different girder types, normally, the sheltering effect of the same wind barrier on streamlined bridge-deck section is much larger than that of bluff bridge-deck section.