Power improvement of NREL 5-MW wind turbine using multi-DBD plasma actuators

The present study numerically investigates the feasibility of using multiple dielectric barrier discharge (multi-DBD) plasma actuators as a novel approach for active flow control over a large horizontal axis wind turbine rotor. The National Renewable Energy Laboratory 5 MW offshore wind turbine is used as the baseline case. This turbine uses pitch control system to adjust the generated power above its rated wind speeds, but at lower speeds, this system remains inactive. In this paper, the operational condition speed is considered lower than the rated wind speed. The mathematical electro-static model is implemented to simulate the effects of plasma actuator on the external flow and the results are incorporated into Navier-Stokes equations as a body force vector. A configuration of multi-DBD plasma actuators was located at inboard part of the blade along the span that produced a chord-wise body force. Three different cases have been considered based on the number of active actuators. It is revealed that the use of multi-DBD actuators placed parallelly one behind the other could enhance the induced velocity; this affects the pressure distribution and increases the aerodynamic torque. Results showed that, for the cases studied, the turbine power increments are respectively 0.85%, 0.77%, and 0.66%. (C) 2017 Elsevier Ltd. All rights reserved.