Aerodynamic optimization of wind turbine airfoil under dynamic stall condition

To alleviate the effects of dynamic stall on wind turbines, this study uses the Kriging model coupled with computational fluid dynamics to optimize the geometric profile of a wind turbine airfoil under dynamic stall conditions based on the classic S809 airfoil. The implicit LU–SGS method is coupled with the dual time-stepping method to calculate the unsteady flowfield. The SST k–ω turbulence and γ–Reθt transition models are employed to solve the N–S equations. With the S809 airfoil as the baseline, the optimization yields an airfoil with a weaker LEV. Simulation results reveal that the maximum drag coefficient of the optimized airfoil decreases by approximately 82.3 % at the design point, and the lift coefficient hysteresis loop decreases significantly. Additionally, applying the optimized airfoil to a wind turbine improves the aerodynamic characteristics under yaw conditions, indicating that the optimization technique is suitable for designing airfoil profiles under dynamic stall conditions.