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Quenching of vortex breakdown oscillations via harmonic modulation

Published online by Cambridge University Press:  06 March 2008

J. M. LOPEZ
Affiliation:
Department of Mathematics and Statistics, Arizona State University, Tempe AZ 85287, USA
Y. D. CUI
Affiliation:
Temasek Laboratories, National University of Singapore, 119260Singapore
F. MARQUES
Affiliation:
Departament de Física Aplicada, Univ. Politècnica de Catalunya, Barcelona 08034, Spain
T. T. LIM
Affiliation:
Department of Mechanical Engineering, National University of Singapore, 119260Singapore

Abstract

Vortex breakdown is a phenomenon inherent to many practical problems, such as leading-edge vortices on aircraft, atmospheric tornadoes, and flame-holders in combustion devices. The breakdown of these vortices is associated with the stagnation of the axial velocity on the vortex axis and the development of a near-axis recirculation zone. For large enough Reynolds number, the breakdown can be time-dependent. The unsteadiness can have serious consequences in some applications, such as tail-buffeting in aircraft flying at high angles of attack. There has been much interest in controlling the vortex breakdown phenomenon, but most efforts have focused on either shifting the threshold for the onset of steady breakdown or altering the spatial location of the recirculation zone. There has been much less attention paid to the problem of controlling unsteady vortex breakdown. Here we present results from a combined experimental and numerical investigation of vortex breakdown in an enclosed cylinder in which low-amplitude modulations of the rotating endwall that sets up the vortex are used as an open-loop control. As expected, for very low amplitudes of the modulation, variation of the modulation frequency reveals typical resonance tongues and frequency locking, so that the open-loop control allows us to drive the unsteady vortex breakdown to a prescribed periodicity within the resonance regions. For modulation amplitudes above a critical level that depends on the modulation frequency (but still very low), the result is a periodic state synchronous with the forcing frequency over an extensive range of forcing frequencies. Of particular interest is the spatial form of this forced periodic state: for modulation frequencies less than about twice the natural frequency of the unsteady breakdown, the oscillations of the near-axis recirculation zone are amplified, whereas for modulation frequencies larger than about twice the natural frequency the oscillations of the recirculation zone are quenched, and the near-axis flow is driven to the steady axisymmetric state. Movies are available with the online version of the paper.

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Papers
Copyright
Copyright © Cambridge University Press 2008

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References

REFERENCES

Arnold, V. I. 1983 Geometrical Methods in the Theory of Ordinary Differential Equations. Springer.CrossRefGoogle Scholar
Arrowsmith, D. K. & Place, C. M. 1990 An Introduction to Dynamical Systems. Cambridge University Press.Google Scholar
Blackburn, H. M. 2002 Three-dimensional instability and state selection in an oscillatory axisymmetric swirling flow. Phys. Fluids 14, 39833996.CrossRefGoogle Scholar
Blackburn, H. M. & Lopez, J. M. 2000 Symmetry breaking of the flow in a cylinder driven by a rotating end wall. Phys. Fluids 12, 26982701.CrossRefGoogle Scholar
Blackburn, H. M. & Lopez, J. M. 2002 Modulated rotating waves in an enclosed swirling flow. J. Fluid Mech. 465, 3358.CrossRefGoogle Scholar
Brons, M., Shen, W. Z., Sorensen, J. N. & Zhu, W. 2007 The influence of imperfections on the flow structure of steady vortex breakdown bubbles. J. Fluid Mech. 578, 453466.CrossRefGoogle Scholar
Chiffaudel, A. & Fauve, S. 1987 Stong resonance in forced oscillatory convection. Phys. Rev. A 35, 40044007.CrossRefGoogle Scholar
Crawford, J. D. & Knobloch, E. 1991 Symmetry and symmetry-breaking bifurcations in fluid dynamics. Annu. Rev. Fluid Mech. 23, 341387.CrossRefGoogle Scholar
Delery, J. M. 1994 Aspects of vortex breakdown. Prog. Aerospace Sci. 30, 159.CrossRefGoogle Scholar
Escudier, M. P. 1984 Observations of the flow produced in a cylindrical container by a rotating endwall. Exps. Fluids 2, 189196.CrossRefGoogle Scholar
Escudier, M. P. 1988 Vortex breakdown: Observations and explanations. Prog. Aerospace Sci. 25, 189229.CrossRefGoogle Scholar
Fornberg, B. 1998 A Practical Guide to Pseudospectral Methods. Cambridge University Press.Google Scholar
Gallaire, F., Chomaz, J.-M. & Huerre, P. 2004 Closed-loop control of vortex breakdown: a model study. J. Fluid Mech. 511, 6793.CrossRefGoogle Scholar
Gambaudo, J. M. 1985 Perturbation of a Hopf bifurcation by an external time-periodic forcing. J. Diffl Equat. 57, 172199.CrossRefGoogle Scholar
Gelfgat, A. Y., Bar-Yoseph, P. Z. & Solan, A. 2001 Three-dimensional instability of axisymmetric flow in a rotating lid-cylinder enclosure. J. Fluid Mech. 438, 363377.CrossRefGoogle Scholar
Hall, P. 1972 Vortex breakdown. Annu. Rev. Fluid Mech. 4, 195218.CrossRefGoogle Scholar
Herrada, M. A. & Shtern, V. 2003 Control of vortex breakdown by temperature gradients. Phys. Fluids 15, 34683477.CrossRefGoogle Scholar
Hourigan, K., Graham, L. W. & Thompson, M. C. 1995 Spiral streaklines in pre-vortex breakdown regions of axisymmetric swirling flows. Phys. Fluids 7, 31263128.CrossRefGoogle Scholar
Hughes, S. & Randriamampianina, A. 1998 An improved projection scheme applied to pseudospectral methods for the incompressible Navier-Stokes equations. Intl J. Num. Meth. Fluids 28, 501521.3.0.CO;2-S>CrossRefGoogle Scholar
Husain, H. S., Shtern, V. & Hussain, F. 2003 Control of vortex breakdown by addition of near-axis swirl. Phys. Fluids 15, 271279.CrossRefGoogle Scholar
Iooss, G. & Adelmeyer, M. 1998 Topics in Bifurcation Theory and Applications, 2nd edn. World Scientific.Google Scholar
Khalil, S., Hourigan, K. & Thompson, M. C. 2006 Response of unconfined vortex breakdown to axial pulsing. Phys. Fluids 18, 038102.CrossRefGoogle Scholar
Knobloch, E. 1996 Symmetry and instability in rotating hydrodynamic and magnetohydrodynamic flows. Phys. Fluids 8, 14461454.CrossRefGoogle Scholar
Kuznetsov, Y. A. 2004 Elements of Applied Bifurcation Theory, 3rd edn. Springer.CrossRefGoogle Scholar
Leibovich, S. 1978 The structure of vortex breakdown. Annu Rev. Fluid Mech. 10, 221246.CrossRefGoogle Scholar
Lopez, J. M. 1990 Axisymmetric vortex breakdown. Part 1. Confined swirling flow. J. Fluid Mech. 221, 533552.CrossRefGoogle Scholar
Lopez, J. M. 2006 Rotating and modulated rotating waves in transitions of an enclosed swirling flow. J. Fluid Mech. 553, 323346.CrossRefGoogle Scholar
Lopez, J. M., Cui, Y. D. & Lim, T. T. 2006 An experimental and numerical investigation of the competition between axisymmetric time-periodic modes in an enclosed swirling flow. Phys. Fluids 18, 104106.CrossRefGoogle Scholar
Lopez, J. M., Marques, F. & Sanchez, J. 2001 Oscillatory modes in an enclosed swirling flow. J. Fluid Mech. 439, 109129.CrossRefGoogle Scholar
Lopez, J. M. & Perry, A. D. 1992a Axisymmetric vortex breakdown. Part 3. Onset of periodic flow and chaotic advection. J. Fluid Mech. 234, 449471.CrossRefGoogle Scholar
Lopez, J. M. & Perry, A. D. 1992b Periodic axisymmetric vortex breakdown in a cylinder with a rotating end wall. Phys. Fluids A 4, 1871.CrossRefGoogle Scholar
Lucca-Negro, O. & O'Doherty, T. 2001 Vortex brekdown: a review. Prog. Energy Combust. Sci. 27, 431481.CrossRefGoogle Scholar
Lugt, H. J. & Abboud, M. 1987 Axisymmetric vortex breakdown with and without temperature effects in a container with a rotating lid. J. Fluid Mech. 179, 179200.CrossRefGoogle Scholar
Mercader, I., Net, M. & Falqués, A. 1991 Spectral methods for high order equations. Comput. Meth. Appl. Mech. Engng 91, 12451251.CrossRefGoogle Scholar
Mitchell, A. M. & Délery, J. 2001 Research into vortex breakdown control. Prog. Aerospace Sci. 37, 385418.CrossRefGoogle Scholar
Mununga, L., Hourigan, K., Thompson, M. C. & Leweke, T. 2004 Confined flow vortex breakdown control using a small rotating disk. Phys. Fluids 16, 47504753.CrossRefGoogle Scholar
Orszag, S. A. & Patera, A. T. 1983 Secondary instability of wall-bounded shear flows. J. Fluid Mech. 128, 347385.CrossRefGoogle Scholar
Schilder, F. & Peckham, B. B. 2007 Computing Arnol''d tongue scenarios. J. Comput. Phys. 220, 932951.CrossRefGoogle Scholar
Sotiropoulos, F. & Ventikos, Y. 2001 The three-dimensional structure of confined swirling flows with vortex breakdown. J. Fluid Mech. 426, 155175.CrossRefGoogle Scholar
Sotiropoulos, F., Webster, D. R. & Lackey, T. C. 2002 Experiments on Lagrangian transport in steady vortex-breakdown bubbles in a confined swirling flow. J. Fluid Mech. 466, 215248.CrossRefGoogle Scholar
Stevens, J. L., Lopez, J. M. & Cantwell, B. J. 1999 Oscillatory flow states in an enclosed cylinder with a rotating endwall. J. Fluid Mech 389, 101118.CrossRefGoogle Scholar
Thompson, M. C. & Hourigan, K. 2003 The sensitivity of steady vortex breakdown bubbles in confined cylinder flows to rotating lid misalignment. J. Fluid Mech. 496, 129138.CrossRefGoogle Scholar
Ventikos, Y. 2002 The effect of imperfections on the emergence of three-dimensionality in stationary vortex breakdown bubbles. Phys. Fluids 14, 1316.CrossRefGoogle Scholar

Lopez et al. supplementary material

Movie 1. Dye flow visualization of vortex breakdown in a confined cylindrical container with the top lid stationary and the bottom lid rotating at a constant angular speed Ω. For the condition shown here, H/R = 2.5 and Re = Ω R2/ν = 2800, where R is the radius of the cylinder and H is the height of the fluid domain (only the central core flow near the axis is shown). The movie shows strong pulsing of the central recirculation zone on the axis and the formation and folding of lobes every period, which follows the detailed description of the chaotic advection given in Lopez & Perry (1992a) for this natural limit cycle flow, LCN.

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Lopez et al. supplementary material

Movies 2 and 3. The flow behaviour when the rotating lid is modulated at Ω(1+A sin(Ωft)), where A is the relative forcing amplitude and Ωf is the forcing frequency. At A = 0.04 and a relatively low forcing frequency of ωf = Ωf/Ω = 0.2, movie 2 shows qualitatively similar behaviour to that in movie 1 without the forcing. On the other hand, at the same forcing amplitude A, but higher forcing frequency of ωf = 0.5, the flow displays a quenching of the oscillations associated with the vortex breakdown bubble, as can be seen in movie 3.

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Video 455 KB

Lopez et al. supplementary material

Movies 2 and 3. The flow behaviour when the rotating lid is modulated at Ω(1+A sin(Ωft)), where A is the relative forcing amplitude and Ωf is the forcing frequency. At A = 0.04 and a relatively low forcing frequency of ωf = Ωf/Ω = 0.2, movie 2 shows qualitatively similar behaviour to that in movie 1 without the forcing. On the other hand, at the same forcing amplitude A, but higher forcing frequency of ωf = 0.5, the flow displays a quenching of the oscillations associated with the vortex breakdown bubble, as can be seen in movie 3.

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Video 371.2 KB

Lopez et al. supplementary material

Movie 4. The laser cross-section of the flow under the same conditions as in movie 3, obtained using fluorescent dye illuminated with a thin laser sheet along the meridional plane. While the vortex breakdown bubble is quenched to a quasi-steady state, there clear evidence of unsteadiness in the bottom left corner region and the sidewall region. An upward propagating wave near the upper sidewall boundary layer region can be also observed.

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Video 2.1 MB

Lopez et al. supplementary material

Movie 5. The computed streamlines ψ (left panel) and azimuthal component of vorticity η (right panel) of the forced limit cycle state LCF under the same conditions as the experimental case in movie 2, i.e. at Re = 2800, H/R = 2.5, A = 0.04 and ωf = 0.2.

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Video 3.3 MB

Lopez et al. supplementary material

Movie 6. The computed streamlines ψ (left panel) and azimuthal component of vorticity η (right panel) of the forced limit cycle state LCF under the same conditions as the experimental cases in movies 3 and 4, i.e. at Re = 2800, H/R = 2.5, A = 0.04 and ωf = 0.5.

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Video 1.9 MB