Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2025-01-05T01:40:03.590Z Has data issue: false hasContentIssue false
  • English
  • Français

A study of forces, circulation and vortex patterns around a circular cylinder in oscillating flow

Published online by Cambridge University Press:  21 April 2006

E. D. Obasaju ,
P. W. Bearman  and
J. M. R. Graham
E. D. Obasaju
Affiliation:
British Maritime Technology Ltd, Teddington, Middlesex. UK
P. W. Bearman
Affiliation:
Department of Aeronautics, Imperial College, London SW7, UK
J. M. R. Graham
Affiliation:
Department of Aeronautics, Imperial College, London SW7, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

Measurements of sectional and total forces and the spanwise correlation of vortex shedding are presented for a circular cylinder in planar oscillatory flow at Keulegan-Carpenter numbers, KC, in the range from about 4 to 55. The viscous parameter β is in the range from around 100 to 1665. Circulation measurements around a circuit close to and enclosing the cylinder, are also presented. A mode-averaging technique was used for both sectional forces and circulation measurements and this gave, for typical modes of vortex shedding, time histories over an average cycle. The transverse force and the circulation tend to fluctuate in sympathy with each other, except around the instant of flow reversal when the force changes sign but the circulation remains high. Values of the strength of shed vortices, estimated from the measured circulation, are found to be comparable with steady-flow results. For KC [lsim ] 30, modes of vortex shedding occur over distinct ranges of KC with spanwise correlation high at the centre of a KC-range for a particular mode of shedding but low at the boundaries. Above KC ≈ 30 the correlation is no longer very sensitive to KC and the correlation length is estimated to be equal to 4.65 cylinder diameters. In the transverse vortex-street regime (8 [lsim ] KC [lsim ] 15) the cylinder was found to experience a steady transverse force, the coefficient of which is estimated to be about 0.5 at KC = 14.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 196 , November 1988 , pp. 467 - 494
Copyright
© 1988 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

Bearman, P. W. 1985 Vortex trajectories in oscillatory flow. In Proc. Intl Symp. on Separated Flow around Marine Structures. Trondheim, Norway, June, pp. 133–153. Norwegian Hydro-dynamic Laboratories, Trondheim. Norway.
Bearman, P. W., Downie, M. J., Graham, J. M. R. & Obasaju, E. D. 1985 Forces on cylinders in viscous oscillatory flow at low Keulegan-Carpenter numbers. J. Fluid Mech. 154, 337–356.Google Scholar
Bearman, P. W., Graham, J. M. R., Naylor, P. & Obasaju, E. D. 1981 The role of vortices in oscillatory flow about bluff cylinders. In Proc. Intl Symp. on Hydrodynamics in Ocean Engng, Trondheim, Norway, August, pp. 621–635. Norwegian Hydrodynamic Laboratories, Trondheim, Norway.
Bearman, P. W., Graham, J. M. R. & Obasaju, E. D. 1984 A model equation for the transverse forces on cylinders in oscillatory flows. Appl. Ocean Res. 6, 166–172.Google Scholar
Gerrard, J. H. 1978 The wake of cylindrical bluff bodies at low Reynolds number. Phil. Trans. R. Soc. Land. 288, 351–382.Google Scholar
Honji, H. 1981 Streaked flow around an oscillating circular cylinder, J. Fluid Mech. 107, 509–520.Google Scholar
Ikeda, S. & Yamamoto, Y. 1981 Lift forces on cylinders in oscillatory flows. Rep. of Dept. Found. Eng. and Const. Eng., Saitama Univ., Japan, 10, pp. 1–16.Google Scholar
Iwagaki, Y., Asano, T. & Nagai, F. 1983 Hydrodynamic forces on a circular cylinders placed in wave-current co-existing fields. Memo Fac. Eng., Kyoto Univ. Japan, vol. 45, pp. 11–23.
Keulegan, G. H. & Carpenter, L. H. 1958 Forces, on cylinders and plates in an oscillating fluid. Natl. Bur. Stand. J. Res. 60, 423–440.Google Scholar
Matten, R. B., Hogben, N. & Ashley, R. M. 1979 A circular cylinder oscillating in still water, in waves and in currents. In Mechanics of Wave-Induced Forces on Cylinders (ed. T. L. Shaw), pp. 475–489. Pitman.
Maull, D. J. & Milliner, M. C. 1978 Sinusoidal flow past a circular cylinder. Coastal Engng 2, 149–168.Google Scholar
Morison, J. R., O'Brien, M. P., Johnson, J. W. & Schaf, S. A. 1950 The force experted by surface waves on piles. Petrol. Trans. 189, 149–157.Google Scholar
Novak, M. & Tanaka, T. 1976 Pressure correlations on a vibrating cylinder. In Wind Effects on Buildings and Structures (ed. K. T. Eaton), pp. 227–232. Cambridge University Press.
Sarpkaya, T. 1975 Forces on cylinders and spheres in a sinusoidally oscillating fluid. Trans. ASME E: J. Appl. Mech. 42, 32–37.Google Scholar
Sarpkaya, T. 1976 Vortex shedding and resistance in harmonic flow about smooth and rough circular cylinders at high Reynolds numbers. Tech. Rep. NPS-59SL76021. Naval Postgraduate School, Monterey, CA.Google Scholar
Sarpkaya, T. 1986 Force on a circular cylinder in viscous oscillatory flow at low Keulegan-Carpenter numbers. J. Fluid Mech. 165, 61–71.Google Scholar
Sarpkaya, T. & Isaacson, M. 1981 Mechanics of Wave Forces on Offshore Structures. Van Nostrand Rheinhold.
Singh, S. 1979 Forces on bodies in oscillatory flow. Ph.D. thesis, University of London.
Stokes, G. G. 1851 On the effect of the internal friction of fluids on the motions of pendulums. Trans. Camb. Phil. Soc. 9, 8–106.Google Scholar
Verley, R. L. P. 1982 A simple model of vortex-induced forces in waves and oscillating currents. Appl. Ocean Res. 4, 117.Google Scholar
Wang, C.-Y. 1968 On high-frequency oscillating viscous flows. J. Fluid Mech. 32, 55–68.Google Scholar
Williamson, C. H. K. 1985 Sinusoidal flow relative to circular cylinders. J. fluid Mech. 155, 141–174.Google Scholar