Curled-Skewed Wakes behind Yawed Wind Turbines Subject to Veered Inflow

Journal Article · Fri Dec 02 00:00:00 UTC 2022 · Energies

DOI: https://doi.org/10.3390/en15239135 · OSTI ID:1908568

Mohammadi, Mohammadreza  ^[1]; Bastankhah, Majid ^[1]; Fleming, Paul  ^[2]; Churchfield, Matthew ^[2]; Bossanyi, Ervin ^[3]; Landberg, Lars  ^[4]; Ruisi, Renzo ^[4]

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1. Durham Univ. (United Kingdom)
2. National Renewable Energy Lab. (NREL), Golden, CO (United States). National Wind Technology Center
3. Bristol University (United Kingdom); DNV (United Kingdom)
4. DNV (United Kingdom)

This work presents a new engineering analytical model that predicts the effect of both the turbine yaw misalignment and the inflow wind veer on the wake flow distribution downwind of a wind turbine. To consider the veered inflow, two methods were examined. In the first method, the curled shape of the wake due to the yaw offset is initially modelled. The wake shape is then laterally skewed at each height due to the wind veer based on the assumption that the turbine wake is transported downstream by the incoming flow. The second method is a more realistic approach that accounts for the effect of wind veer on the wind velocity direction and the yaw angle seen by the wind turbine. This models the wake region in a local coordinate system defined based on the wind direction at each height. A coordinate transformation is then performed to represent the wake flow distribution in the global coordinate system attached to the ground. The results show that while the two methods provide similar outputs for small variations in the wind direction across the rotor, the difference becomes more evident with an increase in wind veer. High-fidelity simulations for a turbine subject to a neutral atmospheric boundary layer were employed to validate model predictions for different operating conditions.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: Innovate UK; USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Wind Energy Technologies Office
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 1908568
• Report Number(s): NREL/JA-5000-84490; MainId:85263; UUID:e3494f8e-d31b-4181-87ba-44977365d6ea; MainAdminID:68128
• Journal Information: Energies, Journal Name: Energies Journal Issue: 23 Vol. 15; ISSN 1996-1073
• Publisher: MDPICopyright Statement
• Country of Publication: United States
• Language: English