Numerical Simulation And Expeirmental Research On Aerodynamic Characteirstics Of Vehicles And Bridges Under Cross Winds

At present, more and more attentions are paid to the safety of vehicles moving on road instrong wind and the wind-vehicle-bridge (WVB) coupled system is getting increasingresearch interest. An accurate identification of the aerodynamic characteristics of vehicles andthe bridge is the premise for the coupling vibration analysis of the WVB system. However, theinteraction of aerodynamic forces between the road vehicles and bridge is ignored in mostprevious researches. The aerodynamic characteristics of vehicles and bridges under crosswinds are investigated by creating a pure bridge model and a vehicle-bridge modelrespectively and by stimulating several cases by means of computational fluid dynamicsapproach (CFD). This thesis also presents the results of wind tunnel experimental research.The main research conducted in this study is presented below.1. After a careful and detailed review of the current research status concerning theaerodynamic characteristics of wind-vehicle system, wind-bridge system, andwind-vehicle-bridge system, issues were pinpointed and the content and objectives of thepresent research were confirmed.2. The CFD simulation technology was systemically researched and the conditions of thevehicle statically placed on the bridge and the vehicle moving on the bridge were simulated.3. The aerodynamic characteristics of the vehicle and bridge were studied understationary vehicles through CFD simulation. The influence of vehicles and wind attack angleson the static aerodynamic forces of the bridge was investigated. The effect of turbulentcharacteristics, the amount and the position of vehicles on the static aerodynamic forces of thebridge and the vehicle were also investigated. The influence of wind yaw angles and theinteraction between the vehicle and bridge on the aerodynamic characteristics of the vehicleand the bridge were analyzed by synthesizing the direction of cross wind and the oppositedirection of driving.4. The aerodynamic characteristics of the vehicle and the bridge were studied undermoving vehicles through CFD simulation. The influence of wind yaw angles and theinteraction between the vehicle and bridge on the aerodynamic characteristics of the vehicleand the bridge were studied. The aerodynamic characteristics of the vehicle and the bridge in the cases of stationary vehicles and moving vehicles were compared.5. An experimental setup was used to measure the aerodynamic characteristics ofvehicles and the bridge for different cases in a wind tunnel considering the aerodynamicinterference. The influence of the wind turbulence, the wind speed, the vehicle interference,and the distance of vehicle from the windward edge on the static aerodynamic forces ofvehicles, and the influence of vehicles on the static aerodynamic forces of the bridge wereinvestigated based on the experimental results. The reasons of change of the aerodynamiccharacteristics of vehicles and the bridge were attempted to be researched and the reliabilityof the measured results was validated according to the results of surface pressure of thevehicle and the bridge. Additionally, the reliability of the results obtained from numericalsimulations was validated by comparing it with the measured results.