Journal ArticleDOI
Vortex shedding from a rectangular prism and a circular cylinder placed vertically in a turbulent boundary layer
Hiroshi Sakamoto,Mikio Arie +1 more
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TLDR
In this article, the Strouhal number for the rectangular prism and the circular cylinder was found to be a power function of the aspect ratio h / w (or h / d ). Here f c is the vortex shedding frequency, U 0 is the free-stream velocity, h is the height, w is the width and d is the diameter.Abstract:
Measurements of the vortex-shedding frequency behind a vertical rectangular prism and a vertical circular cylinder attached to a plane wall are correlated with the characteristics of the smooth-wall turbulent boundary layer in which they are immersed. Experimental data were collected to investigate the effects of (i) the aspect ratio of these bodies and (ii) the boundary-layer characteristics on the vortex-shedding frequency. The Strouhal number for the rectangular prism and the circular cylinder, defined by S = f c w / U 0 and f c d / U 0 respectively, was found to be expressed by a power function of the aspect ratio h / w (or h / d ). Here f c is the vortex-shedding frequency, U 0 is the free-stream velocity, h is the height, w is the width and d is the diameter. As the aspect ratio is reduced, the type of vortex shedding behind each of the two bodies was found to change from the Karman-type vortex to the arch-type vortex at the aspect ratio of 2·0 for the rectangular prism and 2·5 for the circular cylinder.read more
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Wake structure of a finite circular cylinder of small aspect ratio
TL;DR: In this article, the authors studied the wake of a finite circular cylinder of small aspect ratio with a seven-hole probe and thermal anemometry, which was mounted normal to a ground plane and was partially immersed in a turbulent boundary layer.
Journal ArticleDOI
The finite-length square cylinder near wake
Hanfeng Wang,Yu Zhou +1 more
TL;DR: In this article, an experimental investigation of the near wake of a finite-length square cylinder, with one end mounted on a flat plate and the other free, was carried out mainly in a closed-loop low-speed wind tunnel at a Reynolds number Red, based on d and the free-stream velocity of 9300 using hot-wire anemometry, laser Doppler anEMometry and particle image velocimetry (PIV).
Journal ArticleDOI
Measurements of the flow over a low-aspect-ratio cylinder mounted on a ground plane
TL;DR: In this paper, a finite-height cylinder of aspect ratio 1, with one end mounted on a ground plane and the other end free, has been studied by means of surface flow visualisation, particle image velocimetry (PIV) and surface pressure measurements.
Journal ArticleDOI
Free end effects on the near wake flow structure behind a finite circular cylinder
Cheol Woo Park,Sang Joon Lee +1 more
TL;DR: In this paper, the free end effect on the near wake of a finite circular cylinder in a cross flow has been investigated experimentally, and three finite cylinders with aspect ratios (L / D ) of 6, 10 and 13 were tested in a subsonic wind tunnel at a Reynolds number of 20,000.
Journal ArticleDOI
Suppression of vortex-induced vibration of a circular cylinder using suction-based flow control
TL;DR: In this paper, a flow control method is employed to mitigate vortex-induced vibration (VIV) of a circular cylinder by using a suction flow method, and the results indicate clearly that the steady suction-flow control method exhibits excellent control effectiveness and can distinctly suppress the VIV by dramatically reducing the amplitudes of cylinder vibrations, fluctuating pressure coefficients and lift coefficients of the circular cylinder model.
References
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Journal ArticleDOI
The law of the wake in the turbulent boundary layer
TL;DR: In this paper, the authors proposed to represent the mean-velocity profile by a linear combination of two universal functions, namely the law of the wall and the wake, and compared the results with experimental data.
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Kinematical studies of the flows around free or surface-mounted obstacles; applying topology to flow visualization
TL;DR: In this paper, the authors show that the zero-shear-stress points on the surface and on the obstacle must be such that the sum of the nodes and the saddles of the saddle must satisfy
Journal ArticleDOI
The flow around a surface-mounted cube in uniform and turbulent streams
Ian P. Castro,A. G. Robins +1 more
TL;DR: In this article, an experimental investigation of the flow around surface mounted cubes in both uniform, irrotational and sheared, turbulent flows is described, and comparisons with the somewhat sparse measurements of previous workers are made and the relevance of recent theoretical attempts to describe the flow, as opposed to numerical calculation techniques to predict it, is briefly discussed.
Journal ArticleDOI
Flow around a circular cylinder near a plane boundary
P.W. Bearman,M. M. Zdravkovich +1 more
TL;DR: In this article, the authors measured the mean pressure around a circular cylinder placed at various heights above a plane boundary and found that the turbulent boundary layer on the plate at the cylinder position, but with it removed from the tunnel, was equal to 0·8 of the cylinder diameter.
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The laminar horseshoe vortex
TL;DR: In this article, smoke flow visualization shows that both steady and unsteady vortex systems exist and pressure distributions beneath both types of vortex systems have been measured and the variation of the horseshoe vortex position on the plane of symmetry upstream of the cylinder has been determined.