Experimental Investigation of Surface Waves Effect on a Ducted Twin Vertical Axis Tidal Turbine
The cost effective design of tidal turbines requires a good estimation of the loading cycles and their extrema that are related to the unsteady fluctuation of the current velocity. Apart from the ambient turbulence, the main source of velocity fluctuation is the presence of surface waves. In the pre...
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| Format: | Article |
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MDPI AG
2023-09-01
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| Series: | Journal of Marine Science and Engineering |
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| Online Access: | https://www.mdpi.com/2077-1312/11/10/1895 |
| _version_ | 1797573395539296256 |
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| author | Martin Moreau Grégory Germain Guillaume Maurice |
| author_facet | Martin Moreau Grégory Germain Guillaume Maurice |
| author_sort | Martin Moreau |
| collection | DOAJ |
| description | The cost effective design of tidal turbines requires a good estimation of the loading cycles and their extrema that are related to the unsteady fluctuation of the current velocity. Apart from the ambient turbulence, the main source of velocity fluctuation is the presence of surface waves. In the present study, we analyse the effect of waves propagating against the current on the performance and the loads of a twin vertical axis tidal turbine by an experimental approach at a 1/20 scale. Overall, the results show little or no effect of the waves on the average power and loads compared to the conditions with current only, but a significant impact on their standard deviation that rises linearly with the amplitude of the waves. The drag, lift, and pitching moment show extended ranges up to 7.5 times higher and extreme values exceedance by 60 to 100% with irregular waves compared to the conditions without waves. That load and power fluctuation increase is totally due to the presence of waves as the coherence function between the rotor torque or the loads and the velocity spectra exceed 0.5 on the whole wave frequency bandwidth. The results also reveal a rotational sampling of the waves by the rotors that had also been observed on horizontal axis turbines. From a structural design point of view, the authors recommend conducting tests in irregular wave conditions as both the load ranges and extreme values are 1.5 to 2 times higher than those encountered with regular waves of the same significant height and period. |
| first_indexed | 2024-03-10T21:09:03Z |
| format | Article |
| id | doaj.art-9ef3d2d894b54da3886ca4f2707511e0 |
| institution | Directory Open Access Journal |
| issn | 2077-1312 |
| language | English |
| last_indexed | 2024-03-10T21:09:03Z |
| publishDate | 2023-09-01 |
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| record_format | Article |
| series | Journal of Marine Science and Engineering |
| spelling | doaj.art-9ef3d2d894b54da3886ca4f2707511e02023-11-19T16:58:13ZengMDPI AGJournal of Marine Science and Engineering2077-13122023-09-011110189510.3390/jmse11101895Experimental Investigation of Surface Waves Effect on a Ducted Twin Vertical Axis Tidal TurbineMartin Moreau0Grégory Germain1Guillaume Maurice2Ifremer, RDT Research and Technological Development, 62200 Boulogne-sur-Mer, FranceIfremer, RDT Research and Technological Development, 62200 Boulogne-sur-Mer, FranceHydroQuest SAS, 16 Chemin de Malacher, 38240 Meylan, FranceThe cost effective design of tidal turbines requires a good estimation of the loading cycles and their extrema that are related to the unsteady fluctuation of the current velocity. Apart from the ambient turbulence, the main source of velocity fluctuation is the presence of surface waves. In the present study, we analyse the effect of waves propagating against the current on the performance and the loads of a twin vertical axis tidal turbine by an experimental approach at a 1/20 scale. Overall, the results show little or no effect of the waves on the average power and loads compared to the conditions with current only, but a significant impact on their standard deviation that rises linearly with the amplitude of the waves. The drag, lift, and pitching moment show extended ranges up to 7.5 times higher and extreme values exceedance by 60 to 100% with irregular waves compared to the conditions without waves. That load and power fluctuation increase is totally due to the presence of waves as the coherence function between the rotor torque or the loads and the velocity spectra exceed 0.5 on the whole wave frequency bandwidth. The results also reveal a rotational sampling of the waves by the rotors that had also been observed on horizontal axis turbines. From a structural design point of view, the authors recommend conducting tests in irregular wave conditions as both the load ranges and extreme values are 1.5 to 2 times higher than those encountered with regular waves of the same significant height and period.https://www.mdpi.com/2077-1312/11/10/1895tidal energycross-flow turbinetank testssurface waves |
| spellingShingle | Martin Moreau Grégory Germain Guillaume Maurice Experimental Investigation of Surface Waves Effect on a Ducted Twin Vertical Axis Tidal Turbine Journal of Marine Science and Engineering tidal energy cross-flow turbine tank tests surface waves |
| title | Experimental Investigation of Surface Waves Effect on a Ducted Twin Vertical Axis Tidal Turbine |
| title_full | Experimental Investigation of Surface Waves Effect on a Ducted Twin Vertical Axis Tidal Turbine |
| title_fullStr | Experimental Investigation of Surface Waves Effect on a Ducted Twin Vertical Axis Tidal Turbine |
| title_full_unstemmed | Experimental Investigation of Surface Waves Effect on a Ducted Twin Vertical Axis Tidal Turbine |
| title_short | Experimental Investigation of Surface Waves Effect on a Ducted Twin Vertical Axis Tidal Turbine |
| title_sort | experimental investigation of surface waves effect on a ducted twin vertical axis tidal turbine |
| topic | tidal energy cross-flow turbine tank tests surface waves |
| url | https://www.mdpi.com/2077-1312/11/10/1895 |
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