Streamwise oscillations of a cylinder beneath a free surface: Free surface effects on fluid forces

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• 作者：Serpil Kocabiyik^a ; ^{serpil@mun.ca" class="auth_mail" title="E-mail the corresponding author} ; Canan Bozkaya^b ; ^{bcanan@metu.edu.tr" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Unsteady ; Viscous incompressible ; Free surface flow ; Two-fluid model ; Submerged oscillating cylinder ; Fluid forces
• 刊名：Journal of Fluids and Structures
• 出版年：2015
• 出版时间：November 2015
• 年：2015
• 卷：59
• 期：Complete
• 页码：394-405
• 全文大小：2943 K

文摘

A two-dimensional free surface flow past a circular cylinder forced to perform streamwise oscillations in the presence of an oncoming uniform flow is investigated at a Reynolds number of R=200 and fixed displacement amplitude, A  =0.13, for the forcing frequency-to-natural shedding frequency ratios, hmlsrc">hImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0889974615002054&_mathId=si0001.gif&_user=111111111&_pii=S0889974615002054&_rdoc=1&_issn=08899746&md5=0dd139596b5621fda30ee0599d81cb21" title="Click to view the MathML source">f/f₀=1.5hContainer hidden">hCode">h altimg="si0001.gif" overflow="scroll">f/f0=1.5h>, 2.5, 3.5. The present two-fluid model is based on a velocity–pressure formulation of the two-dimensional continuity and unsteady Navier–Stokes equations. The continuity and Navier–Stokes equations are discretized using a finite volume approximation for two fluid regions. An improved volume-of-fluid method is employed to capture for the displacement of the free surface. The objective of this study is to examine the effects of the frequency ratios, hmlsrc">hImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0889974615002054&_mathId=si0001.gif&_user=111111111&_pii=S0889974615002054&_rdoc=1&_issn=08899746&md5=0dd139596b5621fda30ee0599d81cb21" title="Click to view the MathML source">f/f₀=1.5hContainer hidden">hCode">h altimg="si0001.gif" overflow="scroll">f/f0=1.5h>, 2.5, 3.5, and the cylinder submergence depths, h=0.25, 0.5, 0.75, on the fluid forces at a fixed Froude number of Fr=0.2. The relationship between the changes in the wake dynamics of the cylinder described in Bozkaya et al. (2011) and in the properties of fluid forces is also discussed.