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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

An experimental investigation on concomitant Vortex-Induced Vibration and axial top-motion excitation with a long flexible cylinder in vertical configuration

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Author(s):
Franzini, G. R. [1] ; Pesce, C. P. [1] ; Goncalves, R. T. [1, 2] ; Fujarra, A. L. C. [3, 4] ; Mendes, P. [5]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Escola Politecn, LMO Offshore Mech Lab, Sao Paulo - Brazil
[2] Univ Tokyo, Sch Frontier Sci, Tokyo - Japan
[3] Univ Fed Santa Catarina, Dept Mobil Engn, Florianopolis, SC - Brazil
[4] Univ Sao Paulo, LMO, Sao Paulo - Brazil
[5] Petrobras SA, Riser & Flowline Engn Syst, Rio De Janeiro - Brazil
Total Affiliations: 5
Document type: Journal article
Source: OCEAN ENGINEERING; v. 156, p. 596-612, MAY 15 2018.
Web of Science Citations: 1
Abstract

An experimental investigation of concomitant Vortex-Induced Vibration (VIV) and top-motion excitation with a long and vertical flexible cylinder is presented. Underwater optical instrumentation allows to directly measure the cartesian coordinates of 43 targets placed along the model. Standard analyses, based on statistical evaluation of local displacement time-histories and on spectral analysis, are carried out. Additionally to the standard approach, modal decomposition is adopted, allowing to obtain modal-amplitude time-histories. It was found that the concomitant VIV and top-motion excitation significantly affects the flexible cylinder response when compared to the pure VIV tests. When the top-motion excitation has frequency twice the first natural frequency in still water (f(t) f(N,1) = 2 : 1), parametric instability of the first vibration mode occurs concomitant to VIV phenomenon. Such instability leads to a marked increase in the oscillation amplitudes for the whole range of towing speed tested. (AU)

FAPESP's process: 14/02043-1 - Behavior of oil platforms under the action of VIM and simultaneous wave incidence
Grantee:Rodolfo Trentin Gonçalves
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 13/09802-2 - Investigation on the ow around yawed cylinders with low aspect ratio, focusing on the VIM (vortex-induced motion) of floating platforms
Grantee:Guilherme Rosa Franzini
Support Opportunities: Scholarships in Brazil - Post-Doctoral