The effect of static deformation on the lift loss phenomenon of an ABS downforce producing wing in ground effect

The proximity of a downforce producing wing to the ground has a significant effect on the generation of aerodynamic loads and flow structures. However, a rigid body assumption for the wing may lead to inaccuracies in the estimation of these loads. Static loosely-coupled Fluid-Structure Interaction (FSI) simulations were performed at Reynolds numbers of 4.64·10⁵ and 6.96·10⁵ and ground clearances ranging from 0.053 c to 0.223 c to investigate the effect of deformation in an ABS wing. Results of these simulations demonstrated that wing deflection increased the height at which lift loss occurred, as the reduced wing tip ground clearance led to an earlier main wing vortex breakdown and greater boundary layer separation. The increase in Reynolds number for a constant chord length induced larger variations in critical height: the critical height increased by 0.011 c at Re = 4.64·10⁵ and by 0.021 c at Re = 6.96·10⁵. The larger variation in critical height at the high Reynolds number cases was due to the increase in the magnitude of the aerodynamic loads, and larger deflections.