Numerical simulation of laminar flow past a circular cylinder with slip conditions |
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Authors: | Il Won Seo Chang Geun Song |
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Affiliation: | 1. Department of Civil and Environmental Engineering, Seoul National University, 599 Gwanak‐ro, Gwanak‐gu, Seoul 151‐744, South KoreaProfessor.;2. Department of Civil and Environmental Engineering, Seoul National University, 599 Gwanak‐ro, Gwanak‐gu, Seoul 151‐744, South Korea |
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Abstract: | The no‐slip condition is an assumption that cannot be derived from first principles and a growing number of literatures replace the no‐slip condition with partial‐slip condition, or Navier‐slip condition. In this study, the influence of partial‐slip boundary conditions on the laminar flow properties past a circular cylinder was examined. Shallow‐water equations are solved by using the finite element method accommodating SU/PG scheme. Four Reynolds numbers (20, 40, 80, and 100) and six slip lengths were considered in the numerical simulation to investigate the effects of slip length and Reynolds number on characteristic parameters such as wall vorticity, drag coefficient, separation angle, wake length, velocity distributions on and behind the cylinder, lift coefficient, and Strouhal number. The simulation results revealed that as the slip length increases, the drag coefficient decreases since the frictional component of drag is reduced, and the shear layer developed along the cylinder surface tends to push the separation point away toward the rear stagnation point so that it has larger separation angle than that of the no‐slip condition. The length of the wake bubble zone was shortened by the combined effects of the reduced wall vorticity and wall shear stress which caused a shift of the reattachment point closer to the cylinder. The frequency of the asymmetrical vortex formation with partial slip velocity was increased due to the intrinsic inertial effect of the Navier‐slip condition. Copyright © 2011 John Wiley & Sons, Ltd. |
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Keywords: | Navier‐slip condition laminar flow shallow‐water equations SU/PG slip length circular cylinder |
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