Parametric resonances of floating wind turbines blades under vertical wave excitation
The parametric resonances of the blades in floating offshore wind turbines are theoretically and experimentally investigated. In the theoretical analysis, each blade is pinned to a horizontal, rotating shaft and has a spring with rotational stiffness at the end. The blade is subjected to horizontal...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
EDP Sciences
2018-01-01
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| Series: | MATEC Web of Conferences |
| Online Access: | https://doi.org/10.1051/matecconf/201821118004 |
| _version_ | 1828966432335986688 |
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| author | Ikeda Takashi Harata Yuji Miyazawa Yugo Ishida Yukio |
| author_facet | Ikeda Takashi Harata Yuji Miyazawa Yugo Ishida Yukio |
| author_sort | Ikeda Takashi |
| collection | DOAJ |
| description | The parametric resonances of the blades in floating offshore wind turbines are theoretically and experimentally investigated. In the theoretical analysis, each blade is pinned to a horizontal, rotating shaft and has a spring with rotational stiffness at the end. The blade is subjected to horizontal excitation which represents winds; the rotating shaft to vertical excitation which represents waves. The equation of motion for the blade inclination angle includes parametric excitation terms with three different frequencies, i.e., the rotational speed of the blade, and the sum of and difference between the rotational speed and wave excitation frequency. Numerical simulations are conducted for the corresponding linearized system, and it is found that unstable vibrations appear at several rotational speed ranges. An empirical approach is used to determine the regions where the unstable vibrations appear. Swept-sine tests are conducted to determine the frequency response curves for the nonlinear system and demonstrate that the parametric resonances appear at similar rotational speeds as those of the unstable regions. In experiments, parametric resonances were observed at the rotational speeds and wave excitation frequencies predicted by the theoretical analysis. |
| first_indexed | 2024-12-14T11:30:40Z |
| format | Article |
| id | doaj.art-2d5e3d5127964b4f8d292c00d1822689 |
| institution | Directory Open Access Journal |
| issn | 2261-236X |
| language | English |
| last_indexed | 2024-12-14T11:30:40Z |
| publishDate | 2018-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | MATEC Web of Conferences |
| spelling | doaj.art-2d5e3d5127964b4f8d292c00d18226892022-12-21T23:03:17ZengEDP SciencesMATEC Web of Conferences2261-236X2018-01-012111800410.1051/matecconf/201821118004matecconf_vetomacxiv2018_18004Parametric resonances of floating wind turbines blades under vertical wave excitationIkeda TakashiHarata YujiMiyazawa YugoIshida YukioThe parametric resonances of the blades in floating offshore wind turbines are theoretically and experimentally investigated. In the theoretical analysis, each blade is pinned to a horizontal, rotating shaft and has a spring with rotational stiffness at the end. The blade is subjected to horizontal excitation which represents winds; the rotating shaft to vertical excitation which represents waves. The equation of motion for the blade inclination angle includes parametric excitation terms with three different frequencies, i.e., the rotational speed of the blade, and the sum of and difference between the rotational speed and wave excitation frequency. Numerical simulations are conducted for the corresponding linearized system, and it is found that unstable vibrations appear at several rotational speed ranges. An empirical approach is used to determine the regions where the unstable vibrations appear. Swept-sine tests are conducted to determine the frequency response curves for the nonlinear system and demonstrate that the parametric resonances appear at similar rotational speeds as those of the unstable regions. In experiments, parametric resonances were observed at the rotational speeds and wave excitation frequencies predicted by the theoretical analysis.https://doi.org/10.1051/matecconf/201821118004 |
| spellingShingle | Ikeda Takashi Harata Yuji Miyazawa Yugo Ishida Yukio Parametric resonances of floating wind turbines blades under vertical wave excitation MATEC Web of Conferences |
| title | Parametric resonances of floating wind turbines blades under vertical wave excitation |
| title_full | Parametric resonances of floating wind turbines blades under vertical wave excitation |
| title_fullStr | Parametric resonances of floating wind turbines blades under vertical wave excitation |
| title_full_unstemmed | Parametric resonances of floating wind turbines blades under vertical wave excitation |
| title_short | Parametric resonances of floating wind turbines blades under vertical wave excitation |
| title_sort | parametric resonances of floating wind turbines blades under vertical wave excitation |
| url | https://doi.org/10.1051/matecconf/201821118004 |
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