NREL 5-MW wind turbine power improvement by DBD plasma actuator

In this paper, boundary layer control technique is investigated on the NREL-5MW offshore baseline wind turbine blade with numerical simulation of linear DBD plasma actuator in a three-dimensional manner. This wind turbine uses pitch control system to adjust its generated power above its rated speed; but below that the controller is not in function. In the current study, operating condition is set such that the control system is off. Plasma actuator consists of two electrode and dielectric material. One of these electrodes is connected with the air and the other one is encapsulated with the dielectric material. When the necessary high-level AC voltage is applied to electrodes, electric field forms around the actuator and an induced wall jet forms with the ionization of the air around the actuator. Electrostatic model is applied to simulate the effects of plasma actuator and the resulted body force is inserted into flow momentum equations. In the present study, three different control cases are studied. Results show that in all cases, using this actuator leads to improvement of the velocity profile in controlled section, which influences on pressure distribution and results in rotor torque increment. Finally, increasing in torque leads to grows in produced power of the wind turbine. The most increment in output power occurs, when the actuator installed near the root of the blade in the spanwise direction and before low-speed region in the chordwise direction.