Investigation of Active Flow Control on an Extremely Thick Wind Turbine Airfoil

Abstract

Today, modern wind turbine size has become larger than ever. The conventional airfoil near rotor hub cannot provide the structure integrity for the rotor blades. Large diameter wind turbine required for extremely thick airfoil, such as the FX77-W-343 34.4% wind turbine dedicated airfoil. The exceptionally thick airfoil has an unfavorable characteristic, such as sharp stalling and stalling at low angle of attack. To prevent undesired behavior, the FX77-W-343 airfoil with co-flow jet active flow control is simulated in 2-D CFD using STAR-CCM+ to investigate the enhancement in performance. The simulation is done at low Reynolds number of 1,000,000 with injection and suction momentum coefficient of 0.05. The simulation presents promising performance increase of maximum lift coefficient by 190% and improves lift-to-drag ratio by 94%. While sharp stalling behavior cannot be solved with co-flow jet flow control, the operating margin of the extremely thick airfoil is increased by 130% by delaying the stall angle of attack of 8deg.