Hostname: page-component-cd9895bd7-jn8rn Total loading time: 0 Render date: 2024-12-25T23:07:51.792Z Has data issue: false hasContentIssue false
  • English
  • Français

An experimental study of the parallel and oblique vortex shedding from circular cylinders

Published online by Cambridge University Press:  26 April 2006

M. Hammache  and
M. Gharib
M. Hammache
Affiliation:
Department of Applied Mechanics and Engineering Sciences, University of California, San Diego, La Jolla, CA 92093, USA
M. Gharib
Affiliation:
Department of Applied Mechanics and Engineering Sciences, University of California, San Diego, La Jolla, CA 92093, USA
Get access Rights & Permissions [Opens in a new window]

Abstract

An experimental study of the origin of oblique vortex shedding in the laminar wake of circular cylinders was conducted in the range of Reynolds numbers from 40 to 160. Two transverse circular cylinders were positioned upstream of the main shedding cylinder to control the angle of shedding from the main cylinder. The respective distances between each transverse cylinder and the main cylinder were used to induce oblique shedding of different angles, curved shedding, as well as parallel shedding. Measurements of the mean static pressure distribution in the base region of the cylinder and of the mean spanwise component of the velocity in the wake were taken. These measurements revealed that a non-symmetric pressure distribution, which induced a spanwise flow in the base region of the cylinder, was responsible for the oblique shedding. By using a simple model based on the ratio of the streamwise to the spanwise vorticity components, the angle of shedding was predicted within 2° of the value measured from flow visualization. The vorticity was simply evaluated from the spanwise and streamwise velocity profiles of oblique vortex streets obtained with the LDV measurement technique. Parallel vortex shedding showed a symmetric pressure distribution with zero spanwise component of the velocity and zero cross-shear in the cylinder base. It was shown that parallel vortex shedding results in a continuous Strouhal–Reynolds number curve.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 232 , November 1991 , pp. 567 - 590
Copyright
© 1991 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

Eisenlohr, H. & Eckelmann, H. 1989 Vortex splitting and its consequences in the vortex street wake of cylinders at low Reynolds number. Phys. Fluids A 1, 189.Google Scholar
Gaster, M. 1969 Vortex shedding from slender cones at low Reynolds numbers. J. Fluid Mech. 38, 565.Google Scholar
Gerich, D. & Eckelmann, H. 1982 Influence of end plates and free ends on the shedding frequency of circular cylinders. J. Fluid Mech. 122, 109.Google Scholar
hammache, M. & Gharib, M. 1989 A novel method to promote parallel vortex shedding in the wake of circular cylinders. Phys. Fluids A 1, 1611.Google Scholar
Konig, M., Eisenlohr, H. & Eckelmann, H. 1990 The fine structure in the Strouhal-Reynolds number relationship of the laminar wake of a circular cylinder. Phys. Fluids. A 2, 1607.Google Scholar
Maull, D. J. & Young, R. A. 1973 Vortex shedding from bluff bodies in a shear flow. J. Fluid Mech. 60, 401.Google Scholar
Ramberg, S. E. 1983 The effects of yaw and finite length upon the vortex wakes of stationary and vibrating circular cylinders. J. Fluid Mech. 128, 81.Google Scholar
Roshko, A. 1954 On the development of turbulent wakes from vortex streets. NACA Rep. 1191.
Slaouti, A. & Gerrard, J. H. 1981 An experimental investigation on the end effects on the wake of a circular cylinder towed through water at low Reynolds numbers. J. Fluid Mech. 112, 297.Google Scholar
Stansby, P. K. 1974 The effect of end plates on the base pressure coefficient of a circular cylinder. Aero. J. 78, 36.Google Scholar
Tritton, D. J. 1959 Experiments on the flow past a circular cylinder at low Reynolds numbers. J. Fluid Mech. 6, 547.Google Scholar
Van Atta, C. W. & Gharib, M. 1987 Ordered and chaotic vortex streets behind circular cylinders at low Reynolds numbers. J. Fluid Mech. 174, 113.Google 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, 2742.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.Google Scholar
Williamson, C. H. K. & Roshko, A. 1989 Measurements of base pressure in the wake of a cylinder at low Reynolds numbers. Z. Flugwiss. Weltraumforsch. (submitted).Google Scholar