Aerodynamic Study on a Heavy Truck Passing by a Bridge Pylon under Crosswinds Using CFD

High-sided vehicles experience sudden changes in aerodynamic forces when passing through the wake of towers of bridges under crosswind. This may lead, in the worst case, to vehicle rollover or undesired lane changes, thus representing a critical concern for running safety. Computational fluid dynamics (CFD) is used to simulate and investigate the aerodynamic forces acting on a heavy goods vehicle (HGV) during the overtaking maneuver of a bridge tower when the vehicle is passing through the wake of the pylon generated by lateral wind. Dynamic mesh techniques are adopted to simulate the relative velocity between the vehicle and the infrastructure. Such an approach can be used to design lateral shields to be installed on existing infrastructure, reducing the risk of a wind-induced accident involving overturning of the HGV. The validation of the moving mesh strategies is performed comparing numerical and wind tunnel test results in terms of aerodynamic forces and moments acting on a stationary vehicle for different exposure angles.