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Viscous stability properties of a Lamb–Oseen vortex in a stratified fluid

Published online by Cambridge University Press:  22 February 2010

XAVIER RIEDINGER*
Affiliation:
Institut de Recherche sur les Phénomènes Hors Équilibre, CNRS/Universités Aix-Marseille I&II, 49, rue F. Joliot-Curie, BP 146, F-13384 Marseille cedex 13, France
STÉPHANE LE DIZÈS
Affiliation:
Institut de Recherche sur les Phénomènes Hors Équilibre, CNRS/Universités Aix-Marseille I&II, 49, rue F. Joliot-Curie, BP 146, F-13384 Marseille cedex 13, France
PATRICE MEUNIER
Affiliation:
Institut de Recherche sur les Phénomènes Hors Équilibre, CNRS/Universités Aix-Marseille I&II, 49, rue F. Joliot-Curie, BP 146, F-13384 Marseille cedex 13, France
*
Email address for correspondence: xavier.riedinger@gmail.com

Abstract

In this work, we analyse the linear stability of a frozen Lamb–Oseen vortex in a fluid linearly stratified along the vortex axis. The temporal stability properties of three-dimensional normal modes are obtained under the Boussinesq approximation with a Chebychev collocation spectral code for large ranges of Froude numbers and Reynolds numbers (the Schmidt number being fixed to 700). A specific integration technique in the complex plane is used in order to apply the condition of radiation at infinity. For large Reynolds numbers and small Froude numbers, we show that the vortex is unstable with respect to all non-axisymmetrical waves. The most unstable mode is however always a helical radiative mode (m = 1) which resembles either a displacement mode or a ring mode. The displacement mode is found to be unstable for all Reynolds numbers and for moderate Froude numbers (F ~ 1). The radiative ring mode is by contrast unstable only for large Reynolds numbers above 104 and is the most unstable mode for large Froude numbers (F > 2). The destabilization of this mode for large Froude numbers is shown to be associated with a resonance mechanism which is analysed in detail. Analyses of the scaling and of the spatial structure of the different unstable modes are also provided.

Type
Papers
Copyright
Copyright © Cambridge University Press 2010

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References

REFERENCES

Balmforth, N. J. 1999 Shear instability in shallow water. J. Fluid Mech. 387, 97127.CrossRefGoogle Scholar
Billant, P. & Chomaz, J.-M. 2000 Experimental evidence for a new instability of a vertical columnar vortex pair in a strongly stratified fluid. J. Fluid Mech. 418, 167188.CrossRefGoogle Scholar
Billant, P. & Gallaire, F. 2005 Generalized Rayleigh criterion for non-axisymmetric centrifugal instabilities. J. Fluid Mech. 542, 365379.CrossRefGoogle Scholar
Billant, P. & Le Dizès, S. 2009 Waves on a columnar vortex in a strongly stratified fluid. Phys. Fluids. 21, 106602.CrossRefGoogle Scholar
Boubnov, B. M., Gledzer, E. B. & Hopfinger, E. J. 1995 Stratified circular Couette flow: instability and flow regimes. J. Fluid Mech. 292, 333358.CrossRefGoogle Scholar
Boulanger, N., Meunier, P. & Le Dizès, S. 2007 Structure of a tilted stratified vortex. J. Fluid Mech. 583, 443458.CrossRefGoogle Scholar
Boulanger, N., Meunier, P. & Le Dizès, S. 2008 Instability of a tilted vortex in stratified fluid. J. Fluid Mech. 596, 120.CrossRefGoogle Scholar
Briggs, R. J., Daugherty, J. D. & Levy, R. H. 1970 Role of landau damping in cross-field electron beams and inviscid shear flow. Phys. Fluids 13 (6), 421432.CrossRefGoogle Scholar
Broadbent, E. G. & Moore, D. W. 1979 Acoustic destabilization of vortices. Phil. Trans. R. Soc. A 290, 353371.Google Scholar
Cairns, R. A. 1979 The role of negative energy waves in some instabilities of parallel flows. J. Fluid Mech. 92, 114.CrossRefGoogle Scholar
Eloy, C. & Le Dizès, S. 1999 Three-dimensional instability of Burgers and Lamb–Oseen vortices in a strain field. J. Fluid Mech. 378, 145166.CrossRefGoogle Scholar
Esch, R. E. 1957 The instability of a shear layer between two parallel streams. J. Fluid Mech. 3, 289303.CrossRefGoogle Scholar
Fabre, D. & Jacquin, L. 2004 Viscous instabilities in trailing vortices at large swirl numbers. J. Fluid Mech. 500, 239262.CrossRefGoogle Scholar
Fabre, D., Sipp, D. & Jacquin, L. 2006 The Kelvin waves and the singular modes of the Lamb–Oseen vortex. J. Fluid Mech. 551, 235274.CrossRefGoogle Scholar
Ford, R. 1994 The instability of an axisymmetric vortex with monotonic potential vorticity in rotating shallow water. J. Fluid Mech. 280, 303334.CrossRefGoogle Scholar
Fukumoto, Y. 2003 The three-dimensional instability of a strained vortex tube revisited. J. Fluid Mech. 493, 287318.CrossRefGoogle Scholar
Gula, J., Plougonven, R. & Zeitlin, V. 2009 Ageostrophic instabilities of fronts in a channel in a stratified rotating fluid. J. Fluid Mech. 627, 485507.Google Scholar
Hall, I. M., Bassom, A. P. & Gilbert, A. D. 2003 The effect of viscosity on the stability of planar vortices with fine structure. Quart. J. Mech. Appl. Math. 56, 649657.CrossRefGoogle Scholar
Hayashi, Y.-Y. & Young, W. R. 1987 Stable and unstable shear modes of rotating parallel flows in shallow waters. J. Fluid Mech. 184, 477504.CrossRefGoogle Scholar
Healey, J. J. 2006 A new convective instability of the rotating-disk boundary layer with growth normal to the disk. J. Fluid Mech. 560, 279310.CrossRefGoogle Scholar
Hodyss, D. & Nolan, D. S. 2008 The Rossby-inertia-buyancy instability in baroclinic vortices. Phys. Fluids 20, 096602.CrossRefGoogle Scholar
Kelvin, Lord 1880 Vibrations of a columnar vortex. Phil. Mag. 10, 155168.Google Scholar
Knessl, C. & Keller, J. B. 1992 Stability of rotating shear flows in shallow water. J. Fluid Mech. 244, 605614.CrossRefGoogle Scholar
Le Bars, M. & Le Gal, P. 2007 Experimental analysis of the stratorotational instability in a cylindrical Couette flow. Phys. Rev. Lett. 99, 064502.CrossRefGoogle Scholar
LeDizès, S. Dizès, S. 2000 Non-axisymmetric vortices in two-dimensional flows. J. Fluid Mech. 406, 175198.Google Scholar
Le Dizès, S. 2004 Viscous critical-layer analysis of vortex normal modes. Stud. Appl. Math. 112 (4), 315332.Google Scholar
Le Dizès, S. 2008 Inviscid waves on a Lamb–Oseen vortex in a rotating stratified fluid: consequences on the elliptic instability. J. Fluid Mech. 597, 283303.CrossRefGoogle Scholar
Le Dizès, S. & Billant, P. 2006 Instability of an axisymmetric vortex in a stably stratified fluid. In Sixth European Fluid Mechanics Conference, Stockholm, Sweden.Google Scholar
Le Dizès, S. & Billant, P. 2009 Radiative instability in stratified vortices. Phys. Fluids 21, 096602.CrossRefGoogle Scholar
Le Dizès, S. & Lacaze, L. 2005 An asymptotic description of vortex Kelvin modes. J. Fluid Mech. 542, 6996.Google Scholar
Le Dizès, S. & Laporte, F. 2002 Theoretical predictions for the elliptic instability in a two-vortex flow. J. Fluid Mech. 471, 169201.Google Scholar
Lessen, M. & Paillet, F. 1974 The stability of a trailing line vortex. Part 2. Viscous theory. J. Fluid Mech. 65, 769779.CrossRefGoogle Scholar
Luo, K. H. & Sandham, N. D. 1997 Instability of vortical and acoustic modes in supersonic round jets. Phys. Fluids 9, 1003–13.CrossRefGoogle Scholar
Meunier, P. & Leweke, T. 2005 Elliptic instability of a co-rotating vortex pair. J. Fluid Mech. 533, 125159.CrossRefGoogle Scholar
Miyazaki, T. & Fukumoto, Y. 1991 Axisymmetric waves on a vertical vortex in a stratified fluid. Phys. Fluids A 3, 606616.CrossRefGoogle Scholar
Molemaker, M. J., McWilliams, J. C. & Yavneh, I. 2001 Instability and equilibration of centrifugally stable stratified Taylor–Couette flow. Phys. Rev. Lett. 86, 52705273.CrossRefGoogle ScholarPubMed
Molemaker, M. J., McWilliams, J. C. & Yavneh, I. 2005 Baroclinic instability and loss of balance. J. Phys. Oceanogr. 35, 15051517.CrossRefGoogle Scholar
Narayan, R., Goldreich, P. & Goodman, J. 1987 Physics of modes in a differentially rotating system – analysis of the shearing sheet. Mon. Not. R. Astron. Soc. 228, 141.CrossRefGoogle Scholar
Otheguy, P., Chomaz, J.-M. & Billant, P. 2006 Elliptic and zigzag instabilities on co-rotating vertical vortices in a stratified fluid. J. Fluid Mech. 553, 253272.CrossRefGoogle Scholar
Papaloizou, J. C. B. & Pringle, J. E. 1984 The dynamical stability of differentially rotating disks with constant specific angular momentum. Mon. Not. R. Astron. Soc. 208, 721750.Google Scholar
Sakai, S. 1989 Rossby–Kelvin instability: a new type of ageostrophic instability caused by a resonance between Rossby waves and gravity waves. J. Fluid Mech. 202, 149176.CrossRefGoogle Scholar
Satomura, T. 1981 An investigation of shear instability in a shallow water. J. Meteorol. Soc. Jpn 59, 148167.CrossRefGoogle Scholar
Schecter, D. A. 2008 The spontaneous imbalance of an atmospheric vortex at high Rossby number. J. Atmos. Sci. 65, 24982521.Google Scholar
Schecter, D. A., Dubin, D. H. E., Cass, A. C., Driscoll, C. F., Lansky, I. M. & O'Neil, T. M. 2000 Inviscid damping of asymmetries on a two-dimensional vortex. Phys. Fluids 12 (10), 23972412.CrossRefGoogle Scholar
Schecter, D. A. & Montgomery, M. T. 2004 Damping and pumping of a vortex Rossby wave in a monotonic cyclone: critical layer stirring versus inertia–buoyancy wave emission. Phys. Fluids 16, 1334–48.Google Scholar
Schecter, D. A. & Montgomery, M. T. 2006 Conditions that inhibit the spontaneous radiation of spiral intertia–gravity waves from an intense mesoscale cyclone. J. Atmos. Sci. 63, 435456.CrossRefGoogle Scholar
Schecter, D. A., Montgomery, M. T. & Reasor, P. D. 2002 A theory for the vertical alignment of a quasigeostrophic vortex. J. Atmos. Sci. 59 (2), 150168.2.0.CO;2>CrossRefGoogle Scholar
Vanneste, J. & Yavneh, I. 2007 Unbalanced instabilities of rapidly rotating stratified shear flows. J. Fluid Mech. 584, 373396.CrossRefGoogle Scholar
Williams, P. D., Haine, T. W. N. & Read, P. L. 2005 On the generation mechanisms of short-scale unbalanced modes in rotating two-layer flows with vertical shear. J. Fluid Mech. 528, 122.CrossRefGoogle Scholar
Withjack, E. M. & Chen, C. F. 1974 An experimental study of Couette instability of stratified fluids. J. Fluid Mech. 66, 725737.CrossRefGoogle Scholar
Withjack, E. M. & Chen, C. F. 1975 Stability analysis of rotational Couette flow of stratified fluids. J. Fluid Mech. 68, 157175.CrossRefGoogle Scholar
Yavneh, I., McWilliams, J. C. & Molemaker, M. J. 2001 Non-axisymmetric instability of centrifugally stable stratified Taylor–Couette flow. J. Fluid Mech. 448, 121.CrossRefGoogle Scholar