Vortex-induced vibration of a wavy elliptic cylinder

Autor(es)

Assi, Gustavo R. S. ^[1] ; Bearman, Peter W. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Naval Arch & Ocean Eng, Sao Paulo - Brazil

^[2] Imperial Coll, Dept Aeronaut, London - England

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF FLUIDS AND STRUCTURES; v. 80, p. 1-21, JUL 2018.
• Citações Web of Science: 6

Resumo

This paper shows that three-dimensional separation lines on a wavy cylinder may be correlated by the lateral movement of the body responding to flow-induced excitations. Vortex-induced vibration (VIV) of a wavy elliptic cylinder is investigated by mean of experiments in a water channel in the range of Reynold number between 1,500 to 15,000. Results are compared with those for a plain circular cylinder of equivalent diameter with a combined mass-damping parameter of 0.018. Curves of displacement and frequency of vibration showed that the hydroelastic mechanism that drives the wavy cylinder into VIV is not different from that of a plain cylinder. Detailed decomposition of the fluid forces supports this conclusion. The reason for such similar behaviour is the correlation of the sinuous separation lines as the wavy cylinder starts to oscillate. Flow visualization reveals that the three-dimensional surface of the wavy cylinder affects the formation of vortices in the near wake, generating streamwise and cross-flow vorticity associated with the wavelength of the surface. However, once the cylinder is free to respond to VIV, moving in the cross-flow direction, coherent vortex filaments once more dominate the near wake. (C) 2018 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 14/50279-4 - Brasil Research Centre for Gas Innovation
• Beneficiário: Julio Romano Meneghini
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia
• Processo FAPESP: 11/00205-6 - Desenvolvimento de métodos de supressão de vibrações induzidas pelo escoamento em estruturas oceânicas
• Beneficiário: Gustavo Roque da Silva Assi
• Modalidade de apoio: Auxílio à Pesquisa - Regular