Vortex induced vibration of rotating spheres

M. M. Rajamuni, M. C. Thompson, K. Hourigan

Research output: Chapter in Book/Report/Conference proceedingConference PaperOther

3 Citations (Scopus)

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 languageEnglish
Title of host publicationProceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016
PublisherAustralasian Fluid Mechanics Society
ISBN (Electronic)9781740523776
Publication statusPublished - 2016
EventAustralasian Fluid Mechanics Conference 2016 - The University of Western Australia, Perth, Australia
Duration: 5 Dec 20168 Dec 2016
Conference number: 20th

Publication series

NameProceedings of the 20th Australasian Fluid Mechanics Conference, AFMC 2016

Conference

ConferenceAustralasian Fluid Mechanics Conference 2016
Abbreviated titleAFMC 2016
Country/TerritoryAustralia
CityPerth
Period5/12/168/12/16

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