The main contributor to the drag on motor vehicles is pressure drag, which heavily influences the fuel economy of the vehicle as well. The pressure drag forms due to the bluff-body type shape of sport utility vehicles (SUV) which creates an adverse pressure gradient at the rear of the vehicle. Other key areas that highly contribute to the drag on SUVs are around the wheels and the underbody, including the front and rear bumper. These specific locations around the vehicle will be the focus for study during this research. In collaboration with General Motors, this research seeks to reduce the overall drag on a new electric SUV by changing the geometry and/or implementing passive/active flow control techniques on the vehicle.
For this research, two sets of experiments will be conducted in the large scale wind tunnel at CeFPaC, including pressure measurements and forces/moments measurements. Additionally, particle image velocimetry (PIV) may be done as well.
The physical model is a modular design that allows for pieces to be exchanged for various modifications. This allows for the study of how different geometries and passive flow control techniques alter the drag on the vehicle without having to recreate the entire model each time. The front section, the two front wheel housings, and the entire rear can all be removed and swapped for new parts. The underbody additionally has three plates that can removed for inside access of the vehicle, and to make alterations to the underbody design.
