Aerodynamic Characteristics Simulation of Heavy Commercial Vehicles Passing through Expressway Tunnel in Cross Wind

Considering the aerodynamic characteristics of the vehicle traveling under the crosswind and the complexity of the flow field change, this paper uses overset mesh of STAR CCM+ software to carry out CFD simulation analysis on the aerodynamic characteristics of heavy commercial vehicles passing through the highway tunnel of which entrance and exit exist crosswind. Corresponding aerodynamic coefficients and flow field changes around the body at different crosswind speeds and different tunnel forms are monitored. The results show that the yaw moment is sensitive to the speed of crosswind. When a heavy commercial vehicle passes through a tunnel where crosswind increases from 10m/s to 13m/s,the yaw moment change rate increases from 34.8 kN•m/s to 45.9 kN•m/s. It also can be seen in these results is that when passing through two tunnels with a distance, the heavy commercial vehicle’s side force, roll moment and yaw moment change because of the surrounding periodic variation of flow field.