Hostname: page-component-5c6d5d7d68-tdptf Total loading time: 0 Render date: 2024-08-17T17:02:01.289Z Has data issue: false hasContentIssue false

The wake from a cylinder subjected to amplitude-modulated excitation

Published online by Cambridge University Press:  26 April 2006

M. Nakano
Affiliation:
Department of Mechanical Engineering and Mechanics, 354 Packard Laboratory #19, Lehigh University, Bethlehem, PA 18015, USA
D. Rockwell
Affiliation:
Department of Mechanical Engineering and Mechanics, 354 Packard Laboratory #19, Lehigh University, Bethlehem, PA 18015, USA

Abstract

Controlled, amplitude-modulated excitation of a cylinder at low Reynolds number (Re equals; 136) in the cross-stream direction generates several states of response of the near wake including: a locked-in wake structure, which is periodic at the modulation frequency; a period-doubled wake structure, which is periodic at a frequency half the modulation frequency; and a destabilized structure of the wake, which is periodic at the modulation frequency, but involves substantial phase modulations of the vortex formation relative to the cylinder displacement. The occurrence of each of these states depends upon the dimensionless modulation frequency, as well as the nominal frequency and amplitude of excitation. Transition through states of increasing disorder can be attained by either decreasing the modulation frequency or increasing the amplitude of excitation at a constant value of nominal frequency. These states of response in the near wake are crucial in determining whether the far wake is highly organized or incoherent. Both of these extremes are attainable by proper selection of the parameters of excitation.

Type
Research Article
Copyright
© 1993 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

Chomaz, J. M., Huerre, P. & Redekopp, L. T. 1988 Bifurcations to local and global modes in spatially developing flows. Phys. Rev. Lett. 60, 2528.Google Scholar
Cimbala, J. M., Nagib, H.M. & Roshko, A. 1988 Large structure in the far wakes of two-dimensional bluff-bodies. J. Fluid Mech. 190, 265298.Google Scholar
Couder, Y. & Basdevant, C. 1986 Experimental and numerical studies of vortex-couples in two-dimensional flow. J. Fluid Mech. 173, 225251.Google Scholar
Detemple-Laake, E. & Eckelmann, H. 1989 A phenomenology of Karman vortex streets in oscillating flow. Expts Fluids 7, 217227.Google Scholar
Gollub, J. P. & Benson, S. V. 1980 Many routes to turbulent convention. J. Fluid Mech. 100, 449470.Google Scholar
Goodyear, C. C. 1971 Signals and Information. Wiley Interscience.
Griffin, O. M. & Ramberg, S. E. 1974 The vortex-street wakes of vibrating cylinders. J. Fluid Mech. 66, 553576.Google Scholar
Griffin, O. M. & Ramberg, S. E. 1976 Vortex shedding vibrating in-line with an incident uniform flow. J. Fluid Mech. 75, 257271.Google Scholar
Griffin, O. M. & Votaw, C. W. 1972 The vortex street in the wake of a vibrating cylinder J. Fluid Mech. 55, 3148.Google Scholar
Gursul, I., Lusseyran, D. & Rockwell, D. 1990 On interpretation of flow visualization of unsteady shear flows. Expts Fluids 9, 257266.Google Scholar
Huerre, P. & Monkewitz, P. A. 1985 Absolute and convective instabilities in free shear layers. J. Fluid Mech. 159, 151168.Google Scholar
Huerre, P. & Monkewitz, P. A. 1990 Local and global instabilities in spatially developing flows. Ann. Rev. Fluid Mech. 22, 473538.Google Scholar
Karniadakis, G. E. & Triantafyllou, G. S. 1989a Frequency selection and asymptotic states in laminar wakes. J. Fluid Mech. 199, 441469.Google Scholar
Karniadakis, G. E. & Triantafyllou, G. S. 1989b The crisis of transport measures in chaotic flow past a cylinder. Phys. Fluids A 1, 628630.Google Scholar
Koch, W. 1985 Local instability characteristics and frequency determination of self-excited wake flows. J. Sound Vib. 99, 5383.Google Scholar
Monkewitz, P. A. 1988 The absolute and convective nature of instability in two-dimensional wakes at low Reynolds number. Phys. Fluids 31, 9991006.Google Scholar
Monkewitz, P. A. & Nguyen, L. N. 1987 Absolute instability in the near-wake of two-dimensional bluff bodies. J. Fluids Struct. 1, 165184.Google Scholar
Nakano, M. & Rockwell, D. 1991a Destabilization of the Karman vortex street by frequency-modulated excitation. Phys. Fluids 3, 723725.Google Scholar
Nakano, M. & Rockwell, D. 1991b Decoupling of locked-in vortex formation by amplitude-modulated excitation. Phys. Fluids A 3, 723725.Google Scholar
Nuzzi, F., Magness, C. & Rockwell, D. 1992 Three-dimensional vortex formation from an oscillating, non-uniform cylinder. J. Fluid Mech. 238, 3154.Google Scholar
Olinger, D. J. & Sreenivasan, K. R. 1988 Nonlinear dynamics of the wake of an oscillating cylinder. Phys. Rev. Lett. 60, 797800.Google Scholar
Ongoren, A. & Rockwell, D. 1988a Flow structure from an oscillating cylinder. Part 1. Mechanisms of phase shift and recovery of the near wake, J. Fluid Mech. 191, 197223.Google Scholar
Ongoren, A. & Rockwell, D. 1988b Flow structure from an oscillating cylinder. Part 2. Mode competition in the near wake. J. Fluid Mech. 191, 225245.Google Scholar
Paidoussis, M. E. & Moon, F. C. 1988 Nonlinear and chaotic fluidelastic vibrations of a flexible pipe conveying fluid. J. Fluids Struct. 2, 567591.Google Scholar
Rockwell, D. 1990 Active control of globally unstable separated flows. In Intl Symp. on Nonsteady Fluid Dynamics (ed. J. A. Miller & D. P. Telionis). FED, vol. 92, pp. 379394. ASME.
Rockwell, D., Nuzzi, F. & Magness, C. 1991 Period-doubling in the wake of a three-dimensional cylinder. Phys. Fluids A 3, 14771478.Google Scholar
Sreenivasan, K. R. 1985 Transition and turbulence in fluid flows and low-dimensional chaos. In Frontiers in Fluid Mechanics (ed. S. H. Davis & J. L. Lumley). pp. 4167, Springer.
Triantafyllou, G. S. & Karniadakis, G. E. 1989 Forces on a cylinder oscillating in a steady crowflow. In Proc. Eighth OMAE Conf., The Hague, Vol. II, pp. 247252.
Triantafyllou, G. S., Triantafyllou, M. S. & Chryssostomodis, C. 1986 On the formation of vortex streets behind circular cylinders. J. Fluid Mech. 170, 461477.Google Scholar
Van Atta, C. W. & Gharib, M. 1987 Ordered and chaotic vortex streets behind circular cylinders at low Reynolds numbers. J. Fluid Mech. 171, 113133.Google Scholar
Williamson, C. & Roshko, A. 1988 Vortex formation in the wake of an oscillating cylinder. J. Fluid Struct. 2, 355381.Google Scholar