Hostname: page-component-cd9895bd7-gvvz8 Total loading time: 0 Render date: 2024-12-18T19:01:04.008Z Has data issue: false hasContentIssue false
  • English
  • Français

The formation mechanism and shedding frequency of vortices from a sphere in uniform shear flow

Published online by Cambridge University Press:  26 April 2006

Hiroshi Sakamoto  and
Hiroyuki Haniu
Hiroshi Sakamoto
Affiliation:
Department of Mechanical Engineering, Kitami Institute of Technology, Kitami, 090 Japan
Hiroyuki Haniu
Affiliation:
Department of Mechanical Engineering, Kitami Institute of Technology, Kitami, 090 Japan
Get access Rights & Permissions [Opens in a new window]

Abstract

Experiments to investigate the formation mechanism and frequency of vortex shedding from a sphere in uniform shear flow were conducted in a water channel using flow visualization and velocity measurement. The Reynolds number, defined in terms of the sphere diameter and approach velocity at its centre, ranged from 200 to 3000. The shear parameter K, defined as the transverse velocity gradient of the shear flow non-dimensionalized by the above two parameters, was varied from 0 to 0.25. The critical Reynolds number beyond which vortex shedding from the sphere occurred was found to be lower than that for uniform flow and decreased approximately linearly with increasing shear parameter. Also, the Strouhal number of the hairpin-shaped vortex loops became larger than that for uniform flow and increased as the shear parameter increased.

The formation mechanism and the structure of vortex shedding were examined on the basis of series of photographs and subsequent image processing using computer graphics. The range of Reynolds number in the present investigation, extending up to 3000, could be classified into three regions on the basis of this study, and it was observed that the wake configuration did not differ substantially from that for uniform flow. Also, unlike the detachment point of vortex loops in uniform flow, which was irregularly located along the circumference of the sphere, the detachment point in shear flow was always on the high-velocity side.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 287 , 25 March 1995 , pp. 151 - 171
Copyright
© 1995 Cambridge University Press

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

Achenbach, E. 1974 Vortex shedding from spheres. J. Fluid Mech. 62, 209–221.Google Scholar
Auton, T. R. 1987 The lift force on a spherical body in a rotational flow. J. Fluid Mech. 183, 199–218.Google Scholar
Bretherton, F. P. 1962 The motion of rigid particles in a shear flow at low Reynolds number. J. Fluid Mech. 14, 284–304.Google Scholar
Cometta, C. 1957 An investigation of the unsteady flow pattern in the wake of cylinders and spheres using a hot wire probe. Div. Engng, Brown University, Tech. Rep. WT-21.
Dandy, D. S. & Dwyer, A. H. 1990 A sphere in shear flow at finite Reynolds number: effect of shear on particle lift, drag, and heat transfer. J. Fluid Mech. 216, 381–410.Google Scholar
Hall, G. R. 1967 Interaction of the wake from bluff bodies with an initially laminar boundary layer. AIAAJ. 5, 1386–1392.Google Scholar
Kim, K. J. & Durbin, P. A. 1988 Observation of the frequencies in a sphere wake and drag increase by acoustic excitation. Phys. Fluids 31, 3260–3265.Google Scholar
Kiya, M., Tamura, H. & Arie, M. 1980 Vortex shedding from a circular cylinder in moderate-Reynolds number shear flow. J. Fluid Mech. 101, 721–735.Google Scholar
Kotansky, D. R. 1966 The use of honeycomb for shear flow generator. AIAAJ. 4, 1490–1491.Google Scholar
Levi, E. 1980 Three-dimensional wakes: origin and evolution. Proc. ASCM: J. Engng Mech. Div. 106, 659–676.Google Scholar
Magarvey, R. H. & Bishop, R. L. 1961 Transition ranges for three-dimensional wakes. Can. J. Phys. 39, 1418–1422.Google Scholar
Magarvey, R. H. & MacLatchy, C. S. 1965 Vortices in sphere wakes. Can J. Phys. 43, 1649–1656.Google Scholar
Modi, V. J. & Akutsu, T. 1984 Wall confinement effects for spheres in the Reynolds number range of 30–2000. Trans. ASME I: J. Fluids Engn. 106, 66–73.Google Scholar
Möller, W. 1938 Experimentelle untersuchung zur hydromechanik der kugel. Phys. Zeitschrift 39, 57–80.Google Scholar
Morkovin, M. V. 1964 Flow around circular cylinder–A kaleidoscope of challenging fluid phenomena. Symp. on Fully Separated Flows (ed. A. G. Hansen), pp. 102–118. New York: ASME.
O'Neill, M. E. 1968 A sphere in contact with a plane wall in a slow linear shear flow. Chem. Engng Sci. 23, 1293–1298.Google Scholar
Owen, P. R. & Zienkiewicz, H. K. 1957 The production of uniform shear flow in a wind tunnel. J. Fluid Mech. 2, 521–531.Google Scholar
Pao, H. P. & Kao, T. W. 1977 Vortex structure in the wake of a sphere. Phys. Fluids 20, 187–191.Google Scholar
Perry, A. E. & Lim, T. T. 1978 Coherent structures in coflowing jets and wakes. J. Fluid Mech. 88, 451–463.Google Scholar
Perry, A. E. & Watmuff, J. F. 1981 The phase-averaged large-scale structures in three-dimensional turbulent wakes. J. Fluid Mech. 103, 33–51.Google Scholar
Pruppacher, H. R., Le Clair, B. P. & Hamielec, A. E. 1970 Some relations between drag and flow pattern of viscous flow past a sphere and a cylinder at low and intermediate Reynolds numbers. J. Fluid Mech. 44, 781–790.Google Scholar
Saffman, P. G. 1965 The lift on a small sphere in a slow shear flow. J. Fluid Mech. 22, 385–400.Google Scholar
Sakamoto, H. & Haniu, H. 1990 A study on vortex shedding from spheres in a uniform flow. Trans. ASME I: J. Fluids Engng 112, 386–392.Google Scholar
Roshko, A. 1956 On the development of turbulent wakes from vortex streets. NACA Rep. 1191.
Roshko, A. 1976 Structure of turbulent shear flow: a new look. AIAAJ. 14, 1349–1357.Google Scholar
Taneda, S. 1956 Experimental investigation of the wake behind cylinders and plates at low Reynolds numbers. J. Phys. Soc. Japan 11, 302–307.Google Scholar
Taneda, S. 1978 Visual observations of the flow past a sphere at Reynolds numbers between 104 and 106. J. Fluid Mech. 85, 187–192.Google Scholar
Williamson, C. H. K. 1989 Oblique and parallel modes of vortex shedding in the wake of a circular cylinder at low Reynolds numbers. J. Fluid Mech. 206, 579–627.Google Scholar
Woo, H. G. C. & Cermak, J. E. 1992 The production of constant-shear flow. J. Fluid Mech. 234, 279–296.Google Scholar