Experimental investigation of vortex generator influence on wind turbine airfoil aerodynamic performance 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 test setup was established to examine the flow control effects of VGs on the DU93-W-210 airfoil at various turbulence intensities with a Reynolds number of 1.5×10⁵. The pressure coefficients, lift and drag coefficients, and flow separation were measured for static and dynamic conditions. Results showed that when the inflow turbulence intensity increased from 0.50% to 10.18%, VGs effectively delayed flow separation on the airfoil surface, expanding the range of angles of attack for enhanced static aerodynamic performance from 11°–17° to 11°–20°. The maximum lift coefficient increase initially rose and then decreased with higher turbulence intensity (the relative increments under the three conditions were 5.45%, 7.79%, and 6.91%). During deep stall, VGs failed to suppress separation, resulting in increased pressure drag coefficients. Dynamic tests revealed that increased turbulence intensity allowed VGs to enhance lift at wider angles of attack during the downstroke phase. The‌ aerodynamic improvement ‌during downstroke‌ was ‌significantly greater than‌ during ‌the‌ upstroke phase. Flow visualization using tuft methods further validated these findings. This research provides ‌practical‌ guidance for optimizing wind turbine airfoil design ‌in‌ turbulent conditions.