Effect of ground on the shape optimisation of a symmetric aerofoil at low angles of attack

Abstract

Numerical investigation on the aerodynamic characteristics of an optimised NACA0012 aerofoil in-ground effect (IGE) has been performed. Gradient-based shape optimisation was carried out using the ANSYS® 19.0 Adjoint Solver to augment lift over drag ratio (L/D) by at least 10%, at various heights and angles of attack. SST k-ω turbulence model was chosen for the simulations, after its validation for out-of-ground effect (OGE) and performing wind tunnel tests for IGE. While the desired target of 10% increase in the performance parameter was easily achieved through optimisation at low angles of attack (α < 6°), the frozen turbulence assumption in Adjoint Solver limited large shape alterations at higher angles of attack. Upper surface of the aerofoil had larger changes from original camber when compared to the lower surface. Also, the optimised profiles had significant modifications towards x/c ≥ 0.8. This signifies the suitability of trailing edge morphing for such applications.