Aerodynamics of an inverted wing in ground effect: the influence of cornering

The model on which the simulations were performed consists of a single-element rectangular wing, untapered and untwisted, with a chord length c of 223.4 mm and a span of 1100 mm, corresponding to an aspect ratio of 4.92. The wing profile is the main element of the Tyrrell 026 Formula 1 car’s front wing and the coordinates of the airfoil can be found in the thesis by Zerihan [21]. The wing is described in the literature as being at the reference incidence of 3.45° and features rectangular endplates measuring 250 mm × 100 mm × 4 mm. The model of the wing was built using the CAD software ANSYS SpaceClaim. Since the wing is symmetric, straight-line simulations were run only for the semispan with a symmetry plane placed at the midspan location, reducing the total number of mesh cells.
A computational domain reproducing the wind tunnel in which the experiments were conducted was built around the wing. The wind tunnel in the University of Southampton has test-section dimensions of 2.1 m × 1.7 m with an octagonal cross-section and is equipped with a moving belt. For the numerical validation, a simplified rectangular cross-section that matched the maximum extensions of the wind tunnel was used. Another simplification of the numerical model was the use of a moving ground plane across the entire width of the test-section. The ground clearance (or ride height), defined as the distance between the ground and the lowest point of the wing, was set to the reference value of h/c = 0.179, corresponding to approximately 40 mm. The domain was modeled 5c upstream and 20c downstream. Figures 3.2, 3.3 show the computational domain and a close up of the wing semispan.
The origin of the reference frame is located on the leading edge of the wing at the midspan location. The x axis is parallel to the ground and directed downstream; the y axis is orthogonal to the x axis and directed upward; the z axis is directed along the spanwise direction so as to form a right-handed coordinate system.
It is important to notice that, in this configuration, the wing produces a negative lift, i.e. a downforce directed to the ground, but for simplicity the lift coefficient will be indicated with a positive sign. The angle of attack (incidence) is positive when the leading edge of the wing is rotated down.