Experimental study on aerodynamic performance of a wind turbine airfoil with vortex generators under turbulent inflow conditions

This study investigates the effects of vortex generators (VGs) on the aerodynamic performance of a wind turbine airfoil under turbulent inflow conditions. A wind tunnel testing setup was established to examine the flow control effects of VGs on the DU93-W-210 airfoil across various turbulence intensities at a Reynolds number of 1.5 × 10⁵. The pressure coefficients, lift and drag characteristics, and flow separation were analyzed for static and dynamic conditions. Results show that as the inflow turbulence intensity increases from 0.50% to 10.18%, VGs effectively delay flow separation on the airfoil surface, thereby expanding the range of angles of attack that enhance static aerodynamic performance. The increase of the maximum lift coefficient initially increases and then decreases with increasing turbulence intensity. However, VGs are ineffective in suppressing separation during deep stall conditions, leading to higher pressure drag coefficients. Dynamic aerodynamic tests reveal that higher turbulence intensity enables VGs to increase lift at higher angles of attack during the downstroke, with more significant improvements than the upstroke. Flow visualization using tuft methods further validates these findings. This research offers guidance for optimizing wind turbine airfoil design and enhancing its aerodynamic performance in varying turbulent conditions.