Numerical study of trailing edge jet control strategy for horizontal axis wind turbine airfoils

In the operation of horizontal axis wind turbines, the aerodynamic performance of blades is crucial for the efficiency of wind energy conversion. This paper focuses on the airfoils of horizontal axis wind turbine blades, investigates the active flow control method of trailing edge jets, and formulates adjustment strategies to meet the different requirements of the blade tip and root. Numerical simulations are conducted based on the NACA0012 (National Advisory Committee for Aeronautics) airfoil to study its aerodynamic characteristics under different angles of the trailing edge jet. The results show that the trailing edge jet control with negative angles enhances the aerodynamic performance of the airfoil, but this leads to an advanced stall and more severe flow separation. Conversely, the trailing edge jet control with positive angles weakens the aerodynamic performance of the airfoil, but this suppresses flow separation. Based on the control effectiveness of trailing edge jets, two regulation strategies are proposed to meet the design requirements of the blade tip and root, respectively. Strategy 1 satisfies the requirement of tip airfoil; it achieves the highest increase in the average lift-to-drag ratio, with a magnitude of 38.68%; in addition, its stall angle remains not advanced. Strategy 2 satisfies the requirement of root airfoil; it exhibits the smallest closed-loop area of hysteresis, with a notable increase of 27% in the average lift-to-drag ratio. In practical terms, strategy 2 is deemed more superior and practical.