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Abstract / Description of output
A rotor blade operating in an unsteady or a sheared stream experiences force fluctuations, which increase the structural requirements for both the blades and the rotor system as a whole. In this paper, we investigate whether force fluctuations can be passively mitigated without compromising the mean load. We consider a tidal turbine rotor in a shear current at a diameter-based Reynolds number of 2 × 10^7 . The blades are rigid and can passively pitch. A mass-spring system acts on the spanwise axis of the blade governing the pitch kinematics. The effectiveness of this system is demonstrated with three methodologies: an analytical model based on blade element momentum theory and Theodorsen’s theory, and two sets of Reynolds-averaged Navier-Stokes simulations performed with two independent codes. The analytical and the numerical models are validated against experiments and simulations in the literature. All methodologies predict a reduction of more than 80% of the thrust fluctuations. Furthermore, because of the more uniform thrust force exerted on the current, the wake behind a passive pitch blade does not diffuse the onset shear flow. This results in a more sheared wake and in faster wake recovery. The present results demonstrate the potential benefits of passive pitch and may underpin future applications of this concept for different types of turbines and compressors, including wind turbines, propellers, helicopter rotors, etc.
Original language | English |
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Article number | 103599 |
Journal | Journal of fluids and structures |
Volume | 112 |
Early online date | 20 May 2022 |
DOIs | |
Publication status | Published - Jul 2022 |
Keywords / Materials (for Non-textual outputs)
- Turbine rotor
- Unsteady loads
- Tidal energy
- Passive pitch
- Morphing blade
- Fluid-structure interaction
Fingerprint
Dive into the research topics of 'Mitigation of Rotor Thrust Fluctuations through Passive Pitch'. Together they form a unique fingerprint.Projects
- 1 Finished
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Morphing-Blades: New-Concept Turbine Blades for Unsteady Load Mitigation Principal
1/01/21 → 31/12/23
Project: Research
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Morphing Blades: Theory and Proof of Principles
Viola, I. M., Pisetta, G., Dai, W., Arredondo-Galeana, A., Young, A. M. & Smyth, A. S. M., 30 Sept 2022, In: International Marine Energy Journal. 5, 2, p. 183-193Research output: Contribution to journal › Article › peer-review
Open AccessFile -
Morphing Blades for Tidal Turbines: a Theoretical Study
Pisetta, G., Le Mestre, R. & Viola, I. M., 1 Jan 2022, In: Renewable Energy. 183, p. 802-819Research output: Contribution to journal › Article › peer-review
Open AccessFile -
Unsteady load mitigation through a passive trailing-edge flap
Arredondo-Galeana, A., Young, A. M., Smyth, A. S. M. & Viola, I. M., Oct 2021, In: Journal of fluids and structures. 106, 103352.Research output: Contribution to journal › Article › peer-review
Open AccessFile
Datasets
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Dataset for the paper "Mitigation of Rotor Thrust Fluctuations through Passive Pitch"
Dai, W. (Creator) & Viola, I. M. (Creator), Edinburgh DataShare, 29 Mar 2022
DOI: 10.7488/ds/3426
Dataset