Aerodynamics of modern cars is usually investigated in condition of very low turbulence flow and zero yaw. Furthermore, the majority of the tests are often carried out in wind tunnels with fixed ground and static wheels.
The effects of a more realistic flow simulation on the car underbody produced by the ground motion and the wheel rotation have been reported in the SAE paper 980031 presented at the 1998 Int’I SAE Congress.
This parametric study was carried out in the Pininfarina wind tunnel, by using the Ground Effect Simulation System (“GESS”) built in 1995 and a full-scale simplified car model.
This paper reports the follow up of this investigation. The same simplified car model and its underbody interchangeable underbody parts has been tested again, using the “GESS”. However, in the second test session:
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the model has been tested at yaw angles from 0 to -25 degrees, and
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a non-uniform velocity profile and a relatively high turbulence flow have been generated in order to simulate the presence of a side wind.
Results of these tests are then compared with those measured in the past, in condition of uniform velocity and low-turbulence flow.