Flow Control and Separation Reduction on Wind Turbine Airfoil

An innovative passive flow control method is proposed for aerodynamic performance enhancement over the wind turbine airfoils. The new geometry is based on splitting airfoil and is investigated by numerical simulations. Three dimensional CFD simulations are carried out using the SST-k-ω turbulence model. The results show that the split airfoil can produce more lift and less drag by weakening the separation effects and breaking down the large vortex into small vortices. It is observed that level of influence of split depend on split exit location inside the separated flow. For the small AOAs the injected flow through the split triggers an early separation which consequently reduces the airfoil efficiency. However, at high AOA where the upper end of split falls deep inside the separated area, injected flow through the slot effectively increases the airfoil performance. For AOAs at which the separation point occurs near the split exit, the airfoil’s aerodynamic forces are not changed significantly.