A study of an aero-elastic twisted inverted wing in close ground proximity

Aero-elastic deformation of an inverted wing in close ground proximity can have an effect on the aerodynamic loads experienced and the downstream trajectory of the primary tip vortex. These differences have practical application to the front wing installations used in typical open-wheel auto-sport vehicle configurations. A series of moving ground wind tunnel measurements of aerodynamic lift and drag on a simplified inverted-wing-body configuration, at Re/m in the range 1.4 x 106 < Re/m < 2.8 x 106, were compared with RANS CFD simulations on both the un-deflected and deformed body. Measurements of model deformation were obtained using a videogrammetry technique. RANS CFD simulations appear to over-estimate the magnitude of the (-ve) lift coefficient, in very close ground proximity, compared to the experimental data. This may possibly be due to difficulty capturing the interaction between the wing tip vortex and a region of flow separation near the trailing edge, which is particularly apparent at low ground clearances.