Comparison of different approaches for analysing cross-wind effects on high sided vehicles passing by a bridge tower

One of the risks connected to running safety of heavy vehicles is associated to rollover due to the high cross winds which may occur in exposed sites such as embankments, bridges, etc. Specifically, the present paper compares two methodologies for investigating the interaction between a tractor semitrailer combination and the wake of a tower bridge in cross wind conditions. The first methodology employs moving vehicle CFD simulations to evaluate the aerodynamic loads acting on the vehicle. In particular, motion of the vehicle is introduced into the CFD model using a moving mesh approach. The second methodology is instead base on a multi-body vehicle model coupled with a force distribution approach to calculate the aerodynamic forces acting on the vehicle during the tower wake crossing, which relies on static vehicle CFD simulations/wind tunnel tests. In the paper, the results of the two methodologies are presented and compared, illustrating relative advantages and drawbacks.