Numerical Study of the Effect of Corona Discharge on Upward Wake Flow in the Horizontal Axis Wind Turbine Farm

Abstract

Many countries worldwide are showing a growing interest in renewable energy sources, with wind energy being a particularly appealing option for generating mechanical energy. Researchers have explored different techniques for controlling the flow of air, including passive, active, and semi-active methods. In wind farms, the wake flow behind a turbine can be impacted by the flow from other turbines, and to address this issue, plasma-based corona discharge actuators are being considered as one of the most effective methods for reducing fluid flow separation on wind turbine blades. This study employs 2D and 3D numerical simulations to examine the use of corona discharge-based plasma actuators on the leading edge of tandem wind turbines within a wind farm. The study investigates how actuator voltage and frequency affect aerodynamic parameters such as lift, drag coefficients, and efficiency. The study incorporates the use of the Q-criterion to analyze vortex behavior and its interaction with the axial wind turbine body. Fluid flow modeling is conducted using the OPENFOAM software. The findings demonstrate that an escalation in both voltage and frequency of the corona discharge results in a decrease in the Q-criterion, attributed to the heightened ionic flow that diminishes the separation zone. Furthermore, reducing the distance between electrodes also aids in diminishing the Q-criterion values. Additionally, the study reveals that integrating corona plasma at the leading edge of wind turbine blades amplified power generation by more than 3.8%. The corona plasma actuator employed in the study had electrodes spaced 3 mm apart, operated at a voltage of 17 KV, and ran at a frequency of 13 kHz.

Keywords

• flow control
• active flow control
• axial wind turbine
• corona discharge
• plasma actuator