## Abstract

Vortex-induced vibration (VIV) of a sphere is one of the most basic fluid-structure interaction problems. Since such vibrations can lead to fatal structural failures, numerous studies have focused on suppressing such flow-induced vibrations. In this study, for the first time, the effect of an imposed transverse rotation on the dynamics of the VIV of an elastically mounted sphere has been investigated. It was observed that the non-dimensional vibration amplitude for a rotating sphere (A* = √2y_{rms}/D, where y_{rms} is the root mean square of the displacement in the transverse direction and D = sphere diameter) exhibits a bell-shaped evolution as a function of reduced velocity, similar to the classic VIV response of a non-rotating sphere. The sphere is found to oscillate freely up to a rotation ratio α (ratio of the equatorial velocity of the sphere to the free-stream velocity) close to 0.5. For lower rotation ratios (α ≤ 0.3), the response looks similar to the non-rotating case but with slightly smaller vibration amplitude. For higher α values, the amplitude was found to decrease significantly with the rotation up to α = 0.5. The amplitude dropped drastically after it reached the peak amplitude. This is unlike the VIV response of a rotating circular cylinder where the vibration amplitude increases up to three times the maximum vibration amplitude in the non-rotating case due to a novel asymmetric wake pattern (see [1]).

Original language | English |
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Title of host publication | Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016 |

Publisher | Australasian Fluid Mechanics Society |

ISBN (Electronic) | 9781740523776 |

Publication status | Published - 2016 |

Event | Australasian Fluid Mechanics Conference 2016 - The University of Western Australia, Perth, Australia Duration: 5 Dec 2016 → 8 Dec 2016 Conference number: 20th |

### Conference

Conference | Australasian Fluid Mechanics Conference 2016 |
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Abbreviated title | AFMC 2016 |

Country/Territory | Australia |

City | Perth |

Period | 5/12/16 → 8/12/16 |