A New Flow Control and Efficiency Enhancement Method for Horizontal Axis Wind Turbines Based on Segmented Prepositive Elliptical Wings

• Published in: Aerospace Vol. 10; no. 9; p. 796
• Main Authors: Bai, Xuan, Zhan, Hao, Mi, Baigang
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.09.2023
• Subjects: Aerodynamic characteristics; Aerodynamics; Air-turbines; Airfoils; Alternative energy sources; Analysis; Buildings and facilities; computational fluid dynamics (CFD); Design; Efficiency; Energy resources; Finite volume method; Flow control; Flow separation; horizontal axis wind turbine; Horizontal Axis Wind Turbines; Methods; Nuclear energy; prepositive elliptic wing; Simulation; Simulation analysis; Suction; Torque; Turbines; Two dimensional analysis; Two dimensional flow; Vortices; Wind power; Wind speed; Wind turbines
• ISSN: 2226-4310; 2226-4310
• DOI: 10.3390/aerospace10090796

Flow separation occurs when wind turbines operate under large inflow conditions, which seriously affects the utilization of wind energy and reduces the output power of the blade. Therefore, a composite flow control configuration for horizontal axis wind turbines, founded on segmented prepositive elliptical wings, is proposed for efficiency enhancement. Taking a typical NREL Phase VI wind turbine as the prototype, its separation effect is evaluated by the CFD method. Then, starting from the improvement of the two-dimensional airfoil flow, the prepositive elliptic wing is designed according to the airfoil flow, and the optimal two-dimensional flow control configuration of the blade airfoil is obtained by simulation analysis. Finally, the two-dimensional configuration is extended to three-dimensional, and the aerodynamic characteristics of the blade before and after flow control are simulated and compared. The results show that, at wind speeds of 10~20 m/s, flow separation on the blade is effectively inhibited; meanwhile, the pressure difference between the pressure surface and the suction surface increases. These characteristics greatly improve the performance of wind turbine and increase its torque by more than 30%. Moreover, when the flow control effect cannot be reached, the blade torque is only reduced by approximately 2%.