Vortex Drag for a Simple Bluff Body at Incidence in Ground Proximity

Aerodynamic drag is comprised of pressure drag and skin friction only. The drag component associated with lift forces is contained within these two terms. In the case of a simple wing this drag component, called induced drag, is reasonably well defined as a function of lift, but for road vehicles the relationship is more complex. In this paper the drag due to lift, which will be called vortex drag, is investigated for a simple car-like shape at incidence in proximity to the ground. The vortex drag is derived from the parabolic relationship between drag and lift. The effects of ground clearance are considered for both moving a stationary ground simulations. The results are compared with data for other simple bodies.