Plasma-based feed-forward dynamic stall control on a vertical axis wind turbine

Dynamic stall was controlled on a double-bladed H-Rotor vertical axis wind turbine model using pulsed dielectric barrier discharge plasma actuators in a feed-forward control configuration. The azimuthal angles of plasma actuation initiation and termination, that produced the largest increases in power, were determined parametrically on the upstream half of the turbine azimuth in a low-speed blow-down wind tunnel at wind speeds of 7m/s. A mathematical model, together with instantaneous turbine speed, was used to estimate transient torque and power developed by the turbine under the influence of plasma actuation. Overall performance improvements were based on changes between the final actuated and initial baseline results. A remarkable result of this investigation was that a net turbine power increase of 10% was measured. This was achieved by systematically reducing plasma pulsation duty cycles as well as the plasma initiation and termination angles. Nevertheless, it was determined that further performance increases could be achieved by changing the actuator’s dielectric material, increasing the turbine radius and developing a method for control of dynamic stall on both the upwind (inboard of the blades) and downwind (outboard of the blades) halves of the turbine azimuth. Copyright © 2014 John Wiley & Sons, Ltd.