1. The Coriolis force and the direction of rotation of the blades significantly affect the wake of wind turbines
- Author
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Cristina L. Archer, Reza Nouri, and Ahmad Vasel-Be-Hagh
- Subjects
Wind power ,Turbine blade ,business.industry ,Rotor (electric) ,020209 energy ,Mechanical Engineering ,02 engineering and technology ,Building and Construction ,Aerodynamics ,Management, Monitoring, Policy and Law ,Wind direction ,Wake ,Rotation ,Turbine ,law.invention ,General Energy ,020401 chemical engineering ,law ,0202 electrical engineering, electronic engineering, information engineering ,Environmental science ,0204 chemical engineering ,business ,Marine engineering - Abstract
The aerodynamic interactions of wind turbines within a wind farm cause major energy losses. Yaw control is a promising active strategy to tackle this issue in real time during the operation of the plant. The wake of a wind turbine can be steered away from its downstream counterparts by imposing a yaw angle to its rotor. Studying the impact of intentional yaw misalignment on the performance of wind farms located in the northern hemisphere has revealed that, for columns aligned with the wind direction, positive yaw misalignment can lead to an overall increase in the annual energy production, while negative misalignment reduces it. Note that our emphasis is on the front-row turbine being the only yawed turbine of the column. Two unverified reasons have been proposed for the difference between the impact of positive and negative yaw misalignment: (i) the clockwise rotation of the turbine blades and (ii) the Coriolis effect. This paper investigates these two potential explanations by conducting six large-eddy simulations of flow through a wind farm of ten wind turbines located in the northern hemisphere. Results indicate that the Coriolis force and the direction of rotation of the blades both contribute to the inconsistency between the impact of positive and negative yaws on the net power production. The Coriolis force appears to be more influential. The difference between applying a positive and a negative yaw angle to the front-row turbine was found to be approximately 17%. This difference was reduced to almost 7% when the Coriolis force was relaxed, and to approximately 11% when the turbines were set to rotate counter clockwise. Note that a separate study is required to investigate this concept in the southern hemisphere.
- Published
- 2020
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