Flow physics of a race car wing with wortex generators in ground effect

This paper experimentally investigates the use of vortex generators for separation control on an inverted wing in ground effect using off-surface flow measurements and surface flow visualization.A typical racing car wing geometry is tested in a rolling road wind tunnel over a wide range of incidences and ride heights.Rectangular vane type of sub-boundary layer and large-scale vortex generators are attached to the suction surface, comprising counter-rotating and corotating configurations.The effects of both device height and spacing are examined.The counter-rotating sub-boundary layer vortex generators and counter-rotating large-scale vortex generators suppress the flow separation at the center of each device pair, while the counter-rotating large-scale vortex generators induce horseshoe vortices between each device where the flow is separated.The corotating sub-boundary layer vortex generators tested here show little evidence of separation control.Increasing the spacing of the counter-rotating sublayer vortex generator induces significant horseshoe vortices, comparable to those seen in the counter-rotating largescale vortex generator case.Wake surveys show significant spanwise variance behind the wing equipped with the counter-rotating large-scale vortex generators, while the counterrotating sub-boundary layer vortex generator configuration shows a relatively small variance in the spanwise direction.The flow characteristics revealed here suggest that counter-rotating sub-boundary layer vortex generators can provide effective separation control for race car wings in ground effect.