Condition Monitoring of High-Sided Tractor-Trailer Units under Gusty Crosswind Conditions

It is well established that under gusty crosswind conditions, vehicle aerodynamic forces can lead to sudden changes in vehicle dynamics and stability. Large class vehicles, in particular, are more prone to rollover accidents in strong crosswind situations, especially at cruising speeds. It is therefore essential to conduct detailed investigations on the aerodynamic performance of commercial vehicles under crosswind conditions in order to improve their crosswind stability. This study predicts unsteady aerodynamic forces on a high-sided tractor-trailer unit exposed to gusty crosswind conditions. Although natural wind gusts are highly stochastic phenomena, and have a large variability in types and origins, this investigation suggests using deterministic gust model in combination with Computational Fluid Dynamics (CFD) based approach, using Large Eddy simulation (LES) for modeling air turbulence. Crosswind scenario with gusts of exponential shape, as specified in the Technical Specification for Interoperability (TSI), has been presented in the present study. A series of time-dependent aerodynamic interactions on the tractor-trailer unit have been recorded and investigated through the visualization of instantaneous gust flow structures around the truck-trailer unit. The results show that the TSI gust scenario has significant unsteady effects on the side aerodynamic force and the roll moment of the vehicle. Furthermore, there are significant variations in aerodynamic loads, consistent with the gust’s strength.