Study on Aerodynamic Performance of Wind Turbine Airfoil With Combined S-Slot and Trailing Edge Flap Control

Abstract

Reducing the blade aerodynamic loads is extremely important to extend the life of wind turbine blades. Trailing edge flaps are effective means to reduce blade aerodynamic loads, however, its regulation ability weakens greatly at large angles of wind attack. The combined regulation ability on the aerodynamic characteristics of wind turbine blades by S-slot and trailing edge flaps and by adding S-slot at 50% of the chord length of turbine blade was investigated. The shear stress transport (SST) turbulence model was used to study the effect of combined control of S-slot and trailing edge flaps on the aerodynamic characteristics of S809 airfoil at Reynolds number of 106. The synergistic mechanism between the S-slot and trailing edge flaps was further analyzed. The results show that the deflection of trailing edge flaps can significantly change the gas flow rate in the slot, and effectively adjust the pressure difference in the middle of the blade. This combined control strategy can significantly improve the stall phenomenon of airfoil at large angles of wind attack, thereby significantly enhancing the ability of trailing edge flaps to control the lift coefficient.

Keywords

• wind energy
• wind turbine
• airfoil
• airfoil slot
• flap
• aerodynamic performance