Projects per year
Abstract
Waves interact with currents in tidal channels with the resulting wave–current environment largely determining the loads experienced by tidal stream turbines. Over a tidal cycle, the magnitude and direction of the current velocity changes and hence so does the combined wave–current conditions the turbines must operate within. Here we demonstrate this effect experimentally, generating a realistic irregular wave case in both following (in the same direction as the waves) and opposing currents prior to assessing the resulting loads on a fully instrumented 1:15 scale tidal turbine model aligned with the current direction. Large changes in the environmental conditions, along with the turbine performance and loads, are demonstrated through the presentation of temporal, spectral and statistical outputs. The experimental results demonstrate that the full-scale equivalent significant wave height changes from 2.25 m in zero current to 6.11 m in 3.2 m/s opposing current and 1.56 m in 3.2m/s following current. The corresponding standard deviations of measured turbine parameters for the opposing condition range between 215 and 260% of the following case, and between 340 and 565% of the current-only measurements. Hence, when waves are present, significantly greater fatigue damage will be accumulated during one-half of the tidal cycle. The mean values, however, appear to be unaffected by the presence of waves suggesting that the overall turbine performance is unaltered. These results demonstrate the requirement to understand the combined wave–current environment and to test and de-risk tidal stream turbines for operation in both following and opposing wave–current conditions. Significant additional insight is gained into the nature of loads experienced by tidal turbines in irregular wave conditions, a scarcely documented phenomenon.
Original language | English |
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Journal | Journal of Ocean Engineering and Marine Energy |
DOIs | |
Publication status | Published - 3 Jun 2019 |
Keywords / Materials (for Non-textual outputs)
- Tidal stream turbine
- wave loading
- Irregular Waves
- Wave-current interaction
Fingerprint
Dive into the research topics of 'Experimental assessment of tidal turbine loading from irregular waves over a tidal cycle'. Together they form a unique fingerprint.Projects
- 3 Finished
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FloWTurb: Response of Tidal Energy Converters to Combined Tidal Flow, Waves, and Turbulence
Venugopal, V. (Principal Investigator) & Borthwick, A. (Co-investigator)
13/04/16 → 31/10/19
Project: Research
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Extension of UKCMER Core Research, Industry and International Engagement
Wallace, R. (Principal Investigator), Ingram, D. (Co-investigator) & Kiprakis, A. (Co-investigator)
1/01/15 → 31/12/17
Project: Research
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FloWaveTT: UK Centre for marine energy research: The all UK waters, combined, current and wave test facility.
Bryden, I. (Principal Investigator), Ingram, D. (Co-investigator) & Wallace, R. (Co-investigator)
1/10/10 → 28/02/11
Project: Research
Research output
- 1 Article
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Experimental Assessment of Flow, Performance, and Loads for Tidal Turbines in a Closely-Spaced Array
Noble, D. R., Draycott, S., Nambiar, A., Sellar, B. G., Steynor, J. & Kiprakis, A., 16 Apr 2020, In: Energies. 13, 8, 17 p., 1977.Research output: Contribution to journal › Article › peer-review
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