Using system identification in modeling the yaw response of tail fins for small wind turbines with bearing friction

Journal Article · Mon Apr 21 00:00:00 EDT 2025 · Journal of Renewable and Sustainable Energy

DOI:https://doi.org/10.1063/5.0252280· OSTI ID:2565358

Khedr, Amr A. ^[1]; Hammam, Mohamed M. ^[2]; Gupta, Abhineet ^[3]; Castellani, Francesco ^[1]; Wood, David H. ^[4]

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1. University of Perugia (Italy)
2. Port Said University (Egypt)
3. National Renewable Energy Laboratory (NREL), Golden, CO (United States)
4. University of Calgary, AB (Canada)

Here, we describe three main developments of our previous study of the nonlinear yaw dynamics of the tail fins for small wind turbines [Khedr et al., J. Renewable Sustainable Energy 16, 053305 (2024)]. First, the model constants derived from archived computational and experimental studies are adjusted by employing system identification (SI) to maximize the model's agreement with wind tunnel tests. This adjustment was done for high wind speeds, where yaw bearing friction can be ignored. When starting a turbine at low wind speed, however, friction can become important. Our second development is to implement a model for the frictional resistive torque and use SI to maximize its accuracy. These developments used wind tunnel experiments on generic delta, elliptical, and rectangular planforms that were described by Khedr et al. [J. Renewable Sustainable Energy 16, 053305 (2024)]. Since the aerodynamic and friction models employ a large number of constants, we describe ways to constrain the values using linearized solutions of the response equations for small and large yaw angles. Third, we test the generality of the aerodynamic and friction modeling using the complex planform from a commercial small turbine, for which limited theoretical and computational guidance is available in selecting the model constants. The model implemented with SI is shown to provide an accurate description of the yaw response of the complex planform. Guidelines are given for the use of wind tunnel tests to determine the model constants for tail fins of any planform.

• Research Organization: National Renewable Energy Laboratory (NREL), Golden, CO (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Wind Energy Technologies Office
• Grant/Contract Number: AC36-08GO28308
• OSTI ID: 2565358
• Report Number(s): NREL/JA--5000-92258
• Journal Information: Journal of Renewable and Sustainable Energy, Journal Name: Journal of Renewable and Sustainable Energy Journal Issue: 2 Vol. 17; ISSN 1941-7012
• Publisher: American Institute of Physics (AIP)
• Country of Publication: United States
• Language: English

Related Subjects

17 WIND ENERGY
WIND ENERGY
aerodynamics
fluid drag
rotational dynamics
wind turbines