Aerodynamic Optimisations of Vortex Generators on a Wind Turbine Aerofoil using an Adjoint Solver

The adjoint solver (AS) is a relatively new tool with a lot of potential which can optimise a plethora of flow observables in a faster and more automatic manner than other methods, allowing for geometrical and other constraints, which is practically useful for manufacturing and design. To demonstrate this method, a validation case (2D Cylinder) will be simulated and optimised for lower drag, revealing the working patterns and the effect of the different parameters. The AS based optimisations achieve shape convergence after a few steps of iterations with an optimised geometry. This method is subsequently applied first on the aerofoil S809 and compared to benchmark studies. As this aerofoil is often used in a blade section equipped with vortex generators (VGs), CFD simulations will be carried out to study the geometry with VGs, and then a second run of optimisations will be carried out on the VGs aiming for a better lift to drag ratio at operating conditions. It is expected that the optimised shapes will provide a noticeable improvement on the existing design, aiming for higher energy production efficiency and provide a cutting-edge reference for retrofitting in wind industry.