Vortex-induced vibration of floating circular cylinders with very low aspect ratio

Autor(es)

Goncalves, Rodolfo T. ^{[1, 2]} ; Meneghini, Julio R. ^[3] ; Fujarra, Andre L. C. ^{[4, 2]}

Afiliação do(s) autor(es)

^[1] Univ Tokyo, Sch Frontier Sci, Dept Ocean Technol Policy & Environm, 5-1-5 Kashiwa No Ha, Kashiwa, Chiba 2778561 - Japan

^[2] Univ Sao Paulo, Dept Naval Architecture & Ocean Engn, Escola Politecn, TPN Numer Offshore Tank Lab, Sao Paulo, SP - Brazil

^[3] Univ Sao Paulo, Dept Mech Engn, Escola Politecn, Sao Paulo, SP - Brazil

^[4] Univ Fed Santa Catarina, Dept Mobil Engn, Joinville Campus, Joinville, SC - Brazil

• Tipo de documento: Artigo Científico
• Fonte: OCEAN ENGINEERING; v. 154, p. 234-251, APR 15 2018.
• Citações Web of Science: 5

Resumo

Experiments regarding vortex-induced vibration (VIV) on floating circular cylinders with low aspect ratio were carried out in a recirculation water channel. The floating circular cylinders were elastically supported by a set of linear springs. Eight different aspect ratios were tested, namely L/D = 0.2,0.3,0.4,0.5,0.75,1.0,1.5 and 2.0. These aspect ratios were selected to cover the aspect ratio range of the main offshore circular platforms, such as spar and monocolumn. The aim was to understand the vortex-induced motions (VIM) of such platforms; due to this, the cylinders were floating, or m{*} =1. The range of Reynolds number covered 2800 < Re < 55,400. The amplitude results showed a decrease in amplitude with decreasing aspect ratio in the in-line and in the transverse directions. The frequency results confirm a different behavior for cylinders with L/D < 0.5; in these cases, the cylinder free-end effects were predominant. The resonant behavior was no longer observed for L/D < 0.2. The decrease in Strouhal number with decreasing aspect ratio is also verified, as well as for drag and lift forces. The added mass results help to identify the end of resonance for both directions, in-line and transverse. The amplitude results for the vertical direction, roll, pitch and yaw did not affect the VIV behavior. (AU)

• Processo FAPESP: 14/02043-1 - Comportamento de plataformas de petróleo sob a ação do fenômeno de VIM e incidência simultânea de ondas
• Beneficiário: Rodolfo Trentin Gonçalves
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado