Windbreak protection for road vehicles against crosswind

In this study, wind tunnel experiments and a Large Eddy Simulation (LES) model were used to investigate the protective effect of porous windbreak on road vehicles against crosswind. The model prediction of the side force and lift coefficients compared favorably with the wind tunnel experiments of vehicles on the ground. The simulation results of the wake flows behind porous windbreaks were verified by the results of wind tunnel experiments. Then the validated numerical model was used to inspect the effect of porous windbreaks for the protection of vehicles on a bridge. The flow conditions included four different windbreak heights (0, 1, 2 and 3 m) and three different porosities (0, 0.233 and 0.485). The numerical results showed that the porous windbreaks could significantly reduce the side force coefficient of the vehicle, and the side force experienced by the vehicles on the windward lane of the bridge is smaller than that on the leeward lane because of the impermeable concrete barrier and windward windbreak. In addition, the shielding effect of the windbreak height of 2 m plus the barrier of 0.8 m height is sufficient to protect the vehicles of 3.6 m height.