Plasma-based flow control for performance enhancement of vertical-axis wind turbines

A two-dimensional numerical investigation was conducted to evaluate the effects of plasma actuators (PLA) on the aerodynamic performance of a Darrieus vertical-axis wind turbine (VAWT). In the present study, PLAs mounted on turbine blades are employed to control flow separation. First, the flow field around the turbine and the induced field produced by the PLA are numerically simulated and validated. The influences of applied voltage, electrode length, and position on the power curve and flow features are explored. The performance of the PLA under optimal conditions is then evaluated for rotors with two to five blades, and the corresponding power curves are obtained. The results indicate that for a three-bladed rotor, the optimal use of the PLA increases the average power coefficient from 0.241 to 0.447. Moreover, due to the significant effectiveness of the PLA at low tip-speed ratios, the operational stability of the turbine is improved, and the difference between the maximum and minimum power coefficients of the three-bladed rotor over the tip-speed ratio (TSR) range of 1.64 to 3.3 is reduced from 0.24 to 0.09.