The effects of the dual control method on the aerodynamic characteristics of the wind turbine blade

In order to improve the aerodynamic characteristics of small wind turbine blades, a new form of flow control was investigated in this paper. Which was the addition of an S809 airfoil profile slat on the leading edge of blade and a Gurney flap on the trailing edge of the blade. The effects of dual control method on the aerodynamic characteristics were discussed through numerical simulations method. The findings showed that this dual control method increased the fluid velocity on the suction surface of the blade. The fluid could receive higher energy to suppress the inverse pressure gradient in the boundary layer. The blade torque had a significant influence by the dual control method, the total torque of the blade was greatly increased compared to the original blade. The main blade torque of blade-1 was increased by 180.21 N⋅m compared to the original blade at 15.1 m/s. The pressure difference was also increased and the flow separation was restrained, especially near r/R = 0.6. At 10 m/s, the torque coefficients of the r/R = 0.5–0.7 spanwise cross-section were improved by the dual control method. When wind speed was 20.1 m/s, blade-3 increased the torque coefficient from 0.84 to 1.89 at r/R = 0.3 compared to the blade-0, an increase of 125%.