Energy-Efficient Active Flow Control for Enhanced Performance of Vertical Axis Wind Turbine

Active flow control is applied to improve the aerodynamic performance of a NACA0018 airfoil operating as a single-bladed vertical axis wind turbine (VAWT). Results computed by wall-resolved large-eddy simulations (LES) highlight the detrimental effects of the dynamic stall vortex (DSV) and trailing-edge vortex (TEV) on turbine efficiency, primarily through increased drag and energy loss. The present flow control strategy effectively delays flow separation and suppresses large-scale vortex formation, particularly at moderate actuation frequencies. Flow control promotes reattachment and prevents vorticity accumulation, ultimately leading to enhanced torque production. The control strategy is energy-efficient, consuming only 1% of the turbine’s output power while yielding substantial aerodynamic performance gains.