Abstract
The Vortex Induced Vibration (VIV) of an elastically mounted transversely rotating sphere is studied numerically. The sphere is constrained to oscillate orthogonal to the plane made by the direction of the freestream and the axis of sphere rotation. The sphere motion was modelled by a spring-mass system, while the flow was modelled using the incompressible Navier-Stokes equations. The coupled fluid-structure system was solved with the finite-volume based CFD package OpenFOAM by using a newly developed solver. Here, the Navier-Stokes equations were solved in a non-inertial frame centred on the sphere. The effect of the sphere rotation on the VIV was studied at Reynolds number, Re = 300, the density ratio between solid and fluid was m* = 3.8197, and the non-dimensional rotation rate, α, was varied between 0 and 1.5. In addition, the reduced velocity, U*, was varied between 3.5 and 11 to investigate the oscillation amplitude response. Without rotation, the sphere oscillation was found to be synchronised with the vortex shedding frequency, with maximum oscillation amplitude of approximately 0.4 diameters. Two hairpin type vortex streets were observed in the synchronisation regime. With the symmetry breaking introduced by the forced rotation, the oscillation amplitude decreased and the synchronisation regime was narrowed. Furthermore, VIV was suppressed completely for α > 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 |
Publication series
Name | Proceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016 |
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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 |