Larose, G., Belluz, L., Whittal, I., Belzile, M. et al., "Evaluation of the Aerodynamics of Drag Reduction Technologies for Light-duty Vehicles: a Comprehensive Wind Tunnel Study," SAE Int. J. Passeng. Cars - Mech. Syst. 9(2):772-784, 2016, doi:10.4271/2016-01-1613.
In a campaign to quantify the aerodynamic drag changes associated with drag reduction technologies recently introduced for light-duty vehicles, a 3-year, 24-vehicle study was commissioned by Transport Canada. The intent was to evaluate the level of drag reduction associated with each technology as a function of vehicle size class.Drag reduction technologies were evaluated through direct measurements of their aerodynamic performance on full-scale vehicles in the National Research Council Canada (NRC) 9 m Wind Tunnel, which is equipped with a the Ground Effect Simulation System (GESS) composed of a moving belt, wheel rollers and a boundary layer suction system.A total of 24 vehicles equipped with drag reduction technologies were evaluated over three wind tunnel entries, beginning in early 2014 to summer 2015. Testing included 12 sedans, 8 sport utility vehicles, 2 minivans and 2 pick-up trucks.Two categories of drag reduction technologies were evaluated: i) those currently offered by the original equipment manufacturers (i.e. active grille shutters, partial underbody covers, bumper and wheel air dams); and, ii) emerging technologies that have market introduction potential, i.e., active ride height control, actively deployable bumper air dams and full under-body covers.The main findings of the experiments are presented in this paper by categories of vehicles and drag reduction technologies. A discussion on the use of wind averaged drag to evaluate the full impact of the technologies on fuel consumption is also presented.