Experimental Analysis of Aerodynamic Optimization by Vortex Generators on Wind Turbine Airfoils in Turbulent Flow

Wind turbines often operate under complex turbulent environments owing to factors such as the geographic location and wake interference. It remains unclear whether aerodynamic optimization measures for wind turbine airfoils can remain effective in such turbulent environments. To investigate this, the present study utilized wind tunnel pressure measurements to systematically analyze the effects of turbulence intensity—ranging from low to high levels—on the aerodynamic performance enhancements provided by vortex generators. The results indicate that both the incoming turbulence intensity and the vortex generators significantly affect the airfoil’s aerodynamic behavior, with a pronounced interactive constraint observed between these two factors. As the turbulence intensity increased, the maximum lift coefficient of the airfoil initially increased and then decreased, suggesting the presence of a critical turbulence threshold, whereas the stall characteristics of the airfoil continuously improved under turbulent environments. However, when vortex generators were installed at 0.1c~0.2c from the airfoil’s leading-edge, they could effectively suppress boundary layer separation and significantly reduce surface pressure fluctuations, thereby enhancing aerodynamic stability of wind turbine blades. Nevertheless, the aerodynamic optimization effect of vortex generators is highly dependent on turbulence intensity, which exhibits strong dynamic behavior. When the turbulence intensity exceeds a certain threshold, the vortex generators not only lose their effectiveness but may even negatively affect the airfoil’s aerodynamic performance. In contrast, the impact of turbulence intensity on aerodynamic performance is relatively stable and less affected by the arrangement parameters of the vortex generators, essentially maintaining its inherent characteristics.