Please use this identifier to cite or link to this item: http://hdl.handle.net/10397/509
Title: Effect of initial conditions on interaction between a boundary layer and a wall-mounted finite-length-cylinder wake
Authors: Wang, H. F.
Zhou, Yu
Chan, Cheong-ki
Lam, Ka-se
Subjects: Boundary layer turbulence
Wakes
Confined flow
Vortices
Shear turbulence
External flows
Issue Date: 21-Jun-2006
Publisher: American Institute of Physics
Source: Physics of fluids, June 2006, v. 18, no. 6, 065106, p. 1-12.
Abstract: The effects of initial conditions on interaction between a boundary layer over a flat plate and flow around a wall-mounted finite-length cylinder were experimentally investigated. A square cylinder with a characteristic width (d) of 20 mm and a length of H=5d was vertically mounted on a horizontal flat plate. Three different boundary layers were investigated, their momentum thickness being 0.07d, 0.13d, and 0.245d, respectively, measured at the cylinder axis in the absence of the cylinder. All the experiments were carried out in a closed-loop water tunnel at a Reynolds numbers of 11 500 based on d and the free-stream velocity U[sub ∞]. It is found that initial boundary layer conditions have a profound effect on the near wake, including the flow near the cylinder free end that is well beyond the boundary layer. With increasing boundary layer thickness, the base vortex is enhanced, inducing a stronger upwash flow from the cylinder base, which acts to weaken the downwash free-end shear layer and the tip vortex. Consequently, spanwise vortices gain strength near the free end but impair near the wall, causing the ratio of symmetrically to antisymmetrically arranged vortices to vary and subsequently the Reynolds stresses to increase significantly in magnitude near the free end but to decrease near the wall.
Rights: © 2006 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in H.F. Wang et al. Phys. Fluids 18, 065106 (2006) and may be found at http://link.aip.org/link/?phf/18/065106.
Type: Journal/Magazine Article
URI: http://hdl.handle.net/10397/509
ISSN: 1070-6631
Appears in Collections:AMA Journal/Magazine Articles
ME Journal/Magazine Articles
CEE Journal/Magazine Articles

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