The effect of trailing-edge wedge-tails on the aerodynamic characteristics of wind turbine airfoil

Abstract

Passive flow control devices have been proposed by many researchers for suppressing dynamic stall and enhancing the aerodynamic performance of turbomachinery including wind turbines. These technologies are usually cheap, easier to implement, and no additional energy needed. In the present study, the effects of adding trailing edge wedge tail (WT)on the aerodynamic characteristics of a static airfoil have been evaluated. The aerodynamic behavior of 2D-NACA0021 airfoil equipped with WT have been studied numerically using the commercial code ANSYS FLUENT to solve the Reynolds-Averaged Navier–Stokes equation (RANS). The effect of varying heights and lengths to height ratios (L/H) of WT have been studied. The results showed that the aerodynamic efficiency of NACA0021 airfoil influenced significantly by height of WTs comparing to slightly influence by length at L/H<1, and the maximum improvements of the lift and lift-to-drag ratio of the airfoil up to more than +38% and 28.8% respectively at optimum height 1.75%c and length 1%c compared to baseline airfoil case and suggested that to add trailing WTs as a retrofit to existing wind turbines.