Hostname: page-component-586b7cd67f-tf8b9 Total loading time: 0 Render date: 2024-12-01T02:47:10.990Z Has data issue: false hasContentIssue false

The finite-length square cylinder near wake

Published online by Cambridge University Press:  05 October 2009

H. F. WANG
Affiliation:
Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan, People's Republic of China School of Engineering and Architecture, Central South University, Changsha, People's Republic of China
Y. ZHOU*
Affiliation:
Department of Mechanical Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
*
Email address for correspondence: [email protected]

Abstract

This paper reports 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. The cylinder aspect ratio or height-to-width ratio H/d ranges from 3 to 7. Measurements were 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). The planar PIV measurements were performed in the three orthogonal planes of the three-dimensional cylinder wake, along with flow visualization conducted simultaneously in two orthogonal planes (Red = 221). Three types of vortices, i.e. the tip, base and spanwise vortices were observed and the near wake is characterized by the interactions of these vortices. Both flow visualization and two-point correlation point to an inherent connection between the three types of vortices. A model is proposed for the three-dimensional flow structure based on the present measurements, which is distinct from previously proposed models. The instantaneous flow structure around the cylinder is arch-type, regardless of H/d, consisting of two spanwise vortical ‘legs’, one on each side of the cylinder, and their connection or ‘bridge’ near the free end. Both tip and base vortices are the streamwise projections of the arch-type structure in the (y, z) plane, associated with the free-end downwash flow and upwash flow from the wall, respectively. Other issues such as the topological characteristics, spatial arrangement and interactions among the vortical structures are also addressed.

Type
Papers
Copyright
Copyright © Cambridge University Press 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Adaramola, M. S., Akinlade, O. G., Sumner, D., Bergstrom, D. J. & Schenstead, A. J. 2006 Turbulent wake of a finite circular cylinder of small aspect ratio. J. Fluids Struct. 22, 919928.CrossRefGoogle Scholar
Adrian, R. J., Christensen, K. T. & Liu, Z. C. 2000 Analysis and interpretation of instantaneous turbulent velocity fields. Exp. Fluids 29, 275290.CrossRefGoogle Scholar
Afgan, I., Moulinec, C., Prosser, R. & Laurence, D. 2007 Large eddy simulation of turbulent flow for wall mounted cantilever cylinder of aspect ratio 6 and 10. Intl J. Heat Fluid Flow 28, 561574.CrossRefGoogle Scholar
Ayoub, A. & Karamcheti, K. 1982 An experiment on the flow past a finite circular cylinder at high subcritical and supercritical Reynolds numbers. J. Fluid Mech. 118, 126.CrossRefGoogle Scholar
Baban, F., So, R. M. C. & Ötügen, M. V. 1989 Unsteady forces on circular cylinders in a crossflow. Exp. Fluids 7, 293302.CrossRefGoogle Scholar
Balachandar, S., Mittal, R. & Najjar, F. M. 1997 Properties of the mean recirculation region in wakes of two-dimensional bluff bodies. J. Fluid Mech. 351, 167199.CrossRefGoogle Scholar
Bisset, D. K., Antonia, R. A. & Browne, L. W. B. 1990 Spatial organization of large structures in the turbulent far wake of a cylinder. J. Fluid Mech. 218, 439461.CrossRefGoogle Scholar
Bloor, S. M. 1964 The transition to turbulence in the wake of a circular cylinder. J. Fluid Mech. 19, 290309.CrossRefGoogle Scholar
Chyu, C. & Rockwell, D. 1996 Evolution of patterns of streamwise vorticity in the turbulent near wake of a circular cylinder. J. Fluid Mech. 320, 117137.CrossRefGoogle Scholar
Doligalski, T. L., Smith, C. R. & Walker, J. D. A. 1994 Vortex interactions with walls. Annu. Rev. Fluid Mech. 26, 573616.CrossRefGoogle Scholar
Etzold, F. & Fiedler, H. 1976 The near-wake structure of a cantilevered cylinder in a crossflow. Z. Flugwiss. 24, 7782.Google Scholar
Farell, C., Carrasquel, S., Güven, O. & Patel, V. C. 1977 Effect of wind tunnel walls on the flow past circular cylinder and cooling tower models. J. Fluids Engng 99, 470490.CrossRefGoogle Scholar
Farivar, D. 1981 Turbulent uniform flow around cylinders of finite length. AIAA J. 19, 275281.CrossRefGoogle Scholar
Fouras, A., Dusting, J. & Hourigan, K. 2007 A simple calibration technique for stereoscopic particle image velocimetry. Exp. Fluids 42, 799810.CrossRefGoogle Scholar
Fouras, A., Jacono, D. L. & Hourigan, K. 2008 Target-free stereo PIV: a novel technique with inherent error estimation and improved accuracy. Exp. Fluids 44, 317329.CrossRefGoogle Scholar
Fox, T. A. & West, G. S. 1993 a Fluid-induced loading of cantilevered circular cylinder in a low turbulence uniform flow. Part 1. Mean loading with aspect ratios in the range 4 to 30. J. Fluid Struct. 7, 114.CrossRefGoogle Scholar
Fox, T. A. & West, G. S. 1993 b Fluid-induced loading of cantilevered circular cylinders in a low turbulence uniform flow. Part 2. Fluctuating loads on a cantilever of aspect ratio 30. J Fluid Struct. 7, 1528.CrossRefGoogle Scholar
Fröhlich, J. & Rodi, W. 2004 LES of flow around a circular cylinder of finite length. Intl J. Heat Fluid Flow 25, 537548.CrossRefGoogle Scholar
Huang, J. F., Zhou, Y. & Zhou, T. 2006 Three-dimensional wake structure measurement using a modified PIV technique. Exp. Fluids. 40, 884896.CrossRefGoogle Scholar
Hunt, J. C. R., Wray, A. A. & Moin, P. 1998 Eddies, stream and convergence zones in turbulent flow. Tech. Rep. Report CTR-S88. Centre for Turbulence Research, NASA Ames Research Centre and Stanford University, California.Google Scholar
Hussein, H. J. & Martinuzzi, R. J. 1996 Energy balance of turbulent flow around a surface mounted cube placed in a channel. Phys. Fluids 8, 764780.CrossRefGoogle Scholar
Jeong, J. & Hussain, F. 1995 On the identification of a vortex. J. Fluid Mech. 285, 6994.CrossRefGoogle Scholar
Johnston, C. R., Clavelle, E. J., Wilson, D. J. & Peck, B. J. 1998 Investigation of the vorticity generated by flow around a finite cylinder. In Sixth Conference of the CFD Society of Canada, Quebec City, Canada.Google Scholar
Johnston, C. R. & Wilson, D. J. 1997. A vortex pair model for plume downwash into stack wakes. Atmos. Environ. 31, 1320.CrossRefGoogle Scholar
Kawamura, T., Hiwada, M., Hibino, T., Mabuchi, I. & Kumada, M. 1984 Flow around a finite circular cylinder on a flate plate. Bull. JSME 27, 21422150.CrossRefGoogle Scholar
Krajnović, S. & Davidson, L. 2002 Large-eddy simulation of the flow around a bluff body. AIAA J. 40, 927936.CrossRefGoogle Scholar
Kunz, R. F., D'Amico, S. W., Vassallo, P. F. & Zaccaria, M. A. 2001 LDV measurement of confined parallel jet mixing. J. Fluids Engng 123, 567573.CrossRefGoogle Scholar
Lighthill, M. J. 1963 In Laminar Boundary Layers (ed. Rosenhead, L.), pp 4888. Oxford University Press.Google Scholar
Lin, C., Ho, T. C. & Dey, S. 2008 Characteristics of steady horseshoe vortex system near junction of square cylinder and base plate. J. Engng Mech. 134, 184197.Google Scholar
Lourenço, L. M., Krothapalli, A., Buchlin, J. M. & Riethmuller, M. L. 1986 A non-invasive experimental technique for the measurement of unsteady velocity and vorticity fields. AIAA J. 24, 17151717.CrossRefGoogle Scholar
Lyn, D. A., Einav, S. E., Rodi, W. & Park, J. H. 1995 A laser-Doppler velocimetry study of ensemble-averaged characteristics of the turbulent near wake of a square cylinder. J. Fluid Mech. 304, 285319.CrossRefGoogle Scholar
Martinuzzi, R. & Tropea, C. 1993 The flow around surface-mounted, prismatic obstacles placed in a fully developed channel flow. J. Fluids Engng 115, 8592.CrossRefGoogle Scholar
Oertel, H. 1990 Wakes behind bluff bodies. Annu. Rev. Fluid Mech. 22, 539–64.CrossRefGoogle Scholar
Okajima, A. 1982 Strouhal numbers of rectangular cylinders. J. Fluid Mech. 123, 379398.CrossRefGoogle Scholar
Okamoto, T. & Sunabashiri, Y. 1992 Vortex shedding from a circular cylinder of finite length placed on a ground plane. J. Fluids Engng 114, 512521.CrossRefGoogle Scholar
Okamoto, T. & Yagita, M. 1973 The experimental investigation on the flow past a circular cylinder of finite length placed normal to the plane surface. Bull. JSME 16, 805814.CrossRefGoogle Scholar
Park, C. W. & Lee, S. J. 2000 Free end effects on the near wake flow structure behind a finite circular cylinder. J. Wind Engng Ind. Aerodyn. 88, 231246.CrossRefGoogle Scholar
Pattenden, R. J., Turnock, S. R. & Zhang, X. 2005 Measurements of the flow over a low-aspect-ratio cylinder mounted on a ground plane. Exp. Fluids 39, 1021.CrossRefGoogle Scholar
Patterson, R. W. 1982 Turbofan forced mixer-nozzle internal flowfield, I-benchmark experimental study. Tech Rep. CR-3492. NASA.Google Scholar
Perry, A. E. & Chong, M. S. 1987 A description of eddying motions and flow patterns using critical-point concepts. Annu. Rev. Fluid Mech. 19, 125155.CrossRefGoogle Scholar
Raffel, M., Willert, C. E. & Kompenhans, J. 1998 Particle Image Velocimetry: A Practical Guide. Springer Science & Business.CrossRefGoogle Scholar
Saha, A. K., Muralidhar, K. & Biswas, K. 2000 Experimental study of flow past a square cylinder at high Reynolds numbers. Exp. Fluids 29, 553563.CrossRefGoogle Scholar
Sahin, B., Ozturk, N. A. & Akilli, H. 2007 Horseshoe vortex system in the vicinity of the vertical cylinder mounted on a flat plate. Flow Meas. Instrum. 18, 5768.CrossRefGoogle Scholar
Sakamoto, H. & Arie, M. 1983 Vortex shedding from a rectangular prism and a circular cylinder placed vertically in a turbulent boundary layer. J. Fluid Mech. 126, 147165.CrossRefGoogle Scholar
Sakamoto, H. & Oiwake, S. 1984 Fluctuating forces on a rectangular prism and a circular cylinder placed vertically in a turbulent boundary layer. J. Fluids Engng 106, 160166.CrossRefGoogle Scholar
Sarode, R. S., Gai, S. L. & Ramesh, C. K. 1981 Flow around circular- and square-section models of finite height in a turbulent shear flow. J. Wind Engng Ind. Aerodyn. 8, 223230.CrossRefGoogle Scholar
Simpson, R. L. 2001 Junction flow. Annu. Rev. Fluid Mech. 33, 415443.CrossRefGoogle Scholar
Snyder, W. H. & Lawson, R. E. 1994 Wind-tunnel measurements of flow fields in the vicinity of buildings. In Eighth Joint Conference on Applications of Air Pollution Meteorology with A&WMA, Nashville, Tennessee.Google Scholar
Summer, D., Heseltine, J. L. & Dansereau, O. J. P. 2004 Wake structure of a finite circular cylinder of small aspect ratio. Exp. Fluids 37, 720730.CrossRefGoogle Scholar
Tanaka, S. & Murata, S. 1999 An investigation of the wake structure and aerodynamic characteristics of a finite circular cylinder. JSME Intl J. Ser. B: Fluids Therm. Engng 42, 178187.CrossRefGoogle Scholar
Wang, H. F., Zhou, Y. & Chan, C. K. 2005 Flow around a finite length square prism.’ In Proceedings of the Fourth European and African Conference on Wind Engineering Institute of Theoretical and Applied Mechanics, Academy of Sciences of the Czech Republic, Prague.Google Scholar
Wang, H. F., Zhou, Y., Chan, C. K. & Lam, K. S. 2006 Effect of initial conditions on interaction between a boundary layer and a wall-mounted finite-length-cylinder wake. Phys. Fluids 18, 065106.CrossRefGoogle Scholar
Wei, T. & Smith, C. R. 1986 Secondary vortices in the wake of circular cylinder. J. Fluid Mech. 169, 513533.CrossRefGoogle Scholar
Williamson, C. H. K. 1988 Defining a universal and continuous Strouhal–Reynolds number relationship for the laminar vortex shedding of a circular cylinder. Phys. Fluids 31, 27422744.CrossRefGoogle Scholar
Williamson, C. H. K. 1996 Vortex dynamics in the cylinder wake. Annu. Rev. Fluid Mech. 28, 477539.CrossRefGoogle Scholar
Wu, J., Sheridan, J., Welsh, M. C. & Hourigan, K. 1996 Three-dimensional vortex structures in a cylinder wake. J. Fluid Mech. 312, 201222.CrossRefGoogle Scholar
Wu, J., Sheridan, J., Welsh, M. C., Hourigan, K. & Thompson, M. 1994 Longitudinal vortex structures in a cylinder wake. Phys. Fluids 6, 28832885.CrossRefGoogle Scholar
Zdravkovich, M. M. 1997 Flow around circular cylinders, vol 1: Fundamentals. Oxford University Press.CrossRefGoogle Scholar
Zdravkovich, M. M. 2003 Flow around circular cylinders, vol 2: Applications. Oxford University Press.CrossRefGoogle Scholar
Zhong, J. L., Huang, T. S. & Adrian, R. J. 1998 Extracting three-dimensional vortices in turbulent fluid flow. Pattern Anal. Mach. Intell. 20, 193199.CrossRefGoogle Scholar
Zhou, Y. & Antonia, R. A. 1993 A study of turbulent vortices in the wake of a cylinder. J. Fluid Mech. 253, 643661.CrossRefGoogle Scholar
Zhou, Y. & Antonia, R. A. 1994 Critical points in a turbulent near wake. J. Fluid Mech. 275, 5981.CrossRefGoogle Scholar
Zhou, Y., Zhang, H. J. & Yiu, M. W. 2002 The turbulent wake of two side-by-side circular cylinders. J. Fluid Mech. 458, 303332.CrossRefGoogle Scholar