Danao, L.A., Edwards, J., Eboibi, O. et al. (1 more author) (2014) A numerical investigation into the influence of unsteady wind in the performance of a vertical axis wind turbine. Applied Energy, 116. pp. 111-124. ISSN 0306-2619
Abstract
Numerical simulations using RANS–based CFD have been utilised to carry out investigations on the effects of steady and unsteady wind on the performance of a wind tunnel scale VAWT. Using a validated CFD model, steady wind simulations at U∞ = 7m/s were conducted and results have shown a typical performance curve prediction for this particular VAWT scale. Very detailed understandings of the flow physics are discussed showing the importance of stall and flow re-attachment on the performance of the turbine with unsteady winds. The three blades of the VAWT experience very different flow regimes as they rotate during a single periodic oscillation of the wind speed. When the VAWT operates in periodically fluctuating wind conditions, overall performance slightly improves if the following are satisfied: the mean tip speed ratio is just above the λ of the steady performance maximum, the amplitude of fluctuation is small (< 10%), and the frequency of fluctuation is high ( > 1Hz). Operation at a mean λ that is lower than λ for peak performance coefficient causes the VAWT to run in the λ band with deep stall and vortex shedding, to the detriment of the VAWT performance coefficient. Large fluctuations in wind speed causes the VAWT to run in λ conditions that are drag dominated, thus reducing the performance of the wind turbine. Within realistic conditions, higher frequencies of fluctuation marginally improve the performance of the VAWT.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2014 Elsevier. This is an author produced version of a paper subsequently published in Applied Energy. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Mechanical Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 14 Jan 2014 09:38 |
Last Modified: | 15 Sep 2014 02:41 |
Published Version: | http://dx.doi.org/10.1016/j.apenergy.2013.11.045 |
Status: | Published |
Publisher: | Elsevier |
Identification Number: | 10.1016/j.apenergy.2013.11.045 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:77081 |