Aerodynamic Drag Reduction for Ground Vehicles using Lateral Guide Vanes

Abstract

The use of lateral guide vanes as a drag reducing device for ground vehicles is numerically investigated in the present study using computational fluid dynamics. Two types of ground vehicles are considered, a simplified bus model and a simplified sport utility vehicle (SUV) model. The guide vanes are used to direct air into the low-pressure wake region in order to enhance pressure recovery, which in turn would reduce form drag and hence the overall aerodynamic drag. The steady-state simulations are based on the Reynolds-averaged Navier-Stokes equations, with turbulence closure provided through two-equation eddy-viscosity models. Guide vane cross-section, chord length and angle of attack are varied in order to obtain the optimal configuration for improved aerodynamic performance. Simulations indicate an overall reduction in the aerodynamic drag coefficient of up to 18% for the bus and SUV models with the use of the lateral guide vanes. Moreover, it is shown that guide vanes with symmetric airfoil cross-sections result in higher percentage drag reduction as compared to asymmetric cross-sections. Grid-independence tests and comparison with available data in the literature is carried out to validate the present numerical procedure.