Aerodynamic characteristics of vehicle-bridge system under crosswinds and effect of wind barriers

On the basis of the CFD software platform and using the standard k-Ε turbulence model, numerical simulation was performed for the single bridge, single vehicle and vehicle-bridge combination under crosswinds. Their aerodynamic coefficients were calculated for different wind attack angles. The wind barrier-vehicle-bridge model was established in consideration of the effect of wind barriers on aerodynamic performance of the vehicle and bridge. The variation law of the aerodynamic coefficients of the vehicle and bridge with wind barriers of different porosity rates was analyzed. The results show as follows: When a vehicle is running on a bridge, the aerodynamic drag of the bridge and the side force coefficient of the vehicle are amplified; the rolling moment coefficient of the vehicle on the bridge is significantly greater than that of the vehicle alone, and the rolling moment coefficient of the vehicle on the bridge on the windward side is greater than that on the leeward side; the drag and rolling moment coefficient of the bridge with wind barriers decrease with increasing of the porosity percentage where as the above values of the vehicle increase with increasing of the porosity percentage; It is suggested that the porosity percentage of wind barrier should be less than 40% in order to ensure the windbreak effect.