Vortex-induced vibrations of a flexible cylinder at large inclination angle
The free vibrations of a flexible circular cylinder inclined at 80° within a uniform current are investigated by means of direct numerical simulation, at Reynolds number 500 based on the body diameter and inflow velocity. In spite of the large inclination angle, the cylinder exhibits regular in-line...
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| Format: | Article |
| Language: | en_US |
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Royal Society, The
2017
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| Online Access: | http://hdl.handle.net/1721.1/110660 https://orcid.org/0000-0002-4566-5693 https://orcid.org/0000-0002-4960-7060 |
| _version_ | 1826199668703363072 |
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| author | Bourguet, Remi Triantafyllou, Michael S |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Bourguet, Remi Triantafyllou, Michael S |
| author_sort | Bourguet, Remi |
| collection | MIT |
| description | The free vibrations of a flexible circular cylinder inclined at 80° within a uniform current are investigated by means of direct numerical simulation, at Reynolds number 500 based on the body diameter and inflow velocity. In spite of the large inclination angle, the cylinder exhibits regular in-line and cross-flow vibrations excited by the flow through the lock-in mechanism, i.e. synchronization of body motion and vortex formation. A profound reconfiguration of the wake is observed compared with the stationary body case. The vortex-induced vibrations are found to occur under parallel, but also oblique vortex shedding where the spanwise wavenumbers of the wake and structural response coincide. The shedding angle and frequency increase with the spanwise wavenumber. The cylinder vibrations and fluid forces present a persistent spanwise asymmetry which relates to the asymmetry of the local current relative to the body axis, owing to its in-line bending. In particular, the asymmetrical trend of flow–body energy transfer results in a monotonic orientation of the structural waves. Clockwise and counter-clockwise figure eight orbits of the body alternate along the span, but the latter are found to be more favourable to structure excitation. Additional simulations at normal incidence highlight a dramatic deviation from the independence principle, which states that the system behaviour is essentially driven by the normal component of the inflow velocity. |
| first_indexed | 2024-09-23T11:23:37Z |
| format | Article |
| id | mit-1721.1/110660 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T11:23:37Z |
| publishDate | 2017 |
| publisher | Royal Society, The |
| record_format | dspace |
| spelling | mit-1721.1/1106602022-09-27T19:16:00Z Vortex-induced vibrations of a flexible cylinder at large inclination angle Bourguet, Remi Triantafyllou, Michael S Massachusetts Institute of Technology. Department of Mechanical Engineering Triantafyllou, Michael S. Bourguet, Remi Triantafyllou, Michael S The free vibrations of a flexible circular cylinder inclined at 80° within a uniform current are investigated by means of direct numerical simulation, at Reynolds number 500 based on the body diameter and inflow velocity. In spite of the large inclination angle, the cylinder exhibits regular in-line and cross-flow vibrations excited by the flow through the lock-in mechanism, i.e. synchronization of body motion and vortex formation. A profound reconfiguration of the wake is observed compared with the stationary body case. The vortex-induced vibrations are found to occur under parallel, but also oblique vortex shedding where the spanwise wavenumbers of the wake and structural response coincide. The shedding angle and frequency increase with the spanwise wavenumber. The cylinder vibrations and fluid forces present a persistent spanwise asymmetry which relates to the asymmetry of the local current relative to the body axis, owing to its in-line bending. In particular, the asymmetrical trend of flow–body energy transfer results in a monotonic orientation of the structural waves. Clockwise and counter-clockwise figure eight orbits of the body alternate along the span, but the latter are found to be more favourable to structure excitation. Additional simulations at normal incidence highlight a dramatic deviation from the independence principle, which states that the system behaviour is essentially driven by the normal component of the inflow velocity. United States. Office of Naval Research (Grant N00014-07-1-0135) United States. Office of Naval Research (Grant N00014-07-1-0446) 2017-07-12T14:13:59Z 2017-07-12T14:13:59Z 2014-12 Article http://purl.org/eprint/type/JournalArticle 1364-503X 1471-2962 http://hdl.handle.net/1721.1/110660 Bourguet, R., and M. S. Triantafyllou. “Vortex-Induced Vibrations of a Flexible Cylinder at Large Inclination Angle.” Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 373, no. 2033 (December 15, 2014): 20140108–20140108. https://orcid.org/0000-0002-4566-5693 https://orcid.org/0000-0002-4960-7060 en_US http://dx.doi.org/10.1098/rsta.2014.0108 Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Royal Society, The Prof. Triantafyllou via Angie Locknar |
| spellingShingle | Bourguet, Remi Triantafyllou, Michael S Vortex-induced vibrations of a flexible cylinder at large inclination angle |
| title | Vortex-induced vibrations of a flexible cylinder at large inclination angle |
| title_full | Vortex-induced vibrations of a flexible cylinder at large inclination angle |
| title_fullStr | Vortex-induced vibrations of a flexible cylinder at large inclination angle |
| title_full_unstemmed | Vortex-induced vibrations of a flexible cylinder at large inclination angle |
| title_short | Vortex-induced vibrations of a flexible cylinder at large inclination angle |
| title_sort | vortex induced vibrations of a flexible cylinder at large inclination angle |
| url | http://hdl.handle.net/1721.1/110660 https://orcid.org/0000-0002-4566-5693 https://orcid.org/0000-0002-4960-7060 |
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