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Viscous selection of an elliptical dipole

Published online by Cambridge University Press:  20 July 2010

ZIV KIZNER*
Affiliation:
Department of Mathematics, Bar-Ilan University, Ramat-Gan 52900, Israel Department of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel
RUVIM KHVOLES
Affiliation:
Department of Mathematics, Bar-Ilan University, Ramat-Gan 52900, Israel
DAVID A. KESSLER
Affiliation:
Department of Physics, Bar-Ilan University, Ramat-Gan 52900, Israel
*
Email address for correspondence: zinovyk@mail.biu.ac.il

Abstract

A theory of viscous evolution and selection of symmetric two-dimensional dipoles is suggested, based on a combination of numerical simulations and an asymptotic analysis, where the slow time scale associated with the vorticity diffusion due to viscosity is incorporated. It is shown that viscosity first brings a dipole to an intermediate asymptotic state, which is independent of the initial conditions, and then slowly takes the dipole away from this state. We demonstrate that, among the variety of possible ideal-fluid dipole solutions, viscosity going to zero selects a unique solution, which is described to high accuracy by the elliptical dipole solution with a separatrix aspect ratio of 1.037.

Type
Papers
Copyright
Copyright © Cambridge University Press 2010

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References

REFERENCES

Bouchet, F. & Sommeria, J. 2002 Emergence of intense jets and Jupiter's Great Red Spot as maximum-entropy structures. J. Fluid Mech. 464, 165207.CrossRefGoogle Scholar
Boyd, J. P. & Ma, H. 1990 Numerical study of elliptical modons using spectral methods. J. Fluid Mech. 221, 597611.CrossRefGoogle Scholar
Chaplygin, S. A. 1903 One case of vortex motion in fluid. Trans. Phys. Sect. Imperial Mosc. Soc. Friends Nat. Sci. 11, 1114 (translation in Reg. Chaot. Dyn. 12 (2007), 102–114).Google Scholar
Chavanis, P. H. & Sommeria, J. 2002 Statistical mechanics of the shallow water systems. Phys. Rev. E 65, 026302.Google Scholar
Chavanis, P. H., Sommeria, J. & Robert, R. 1996 Statistical mechanics of two-dimensional vortices and collisionless stellar systems. Astrophys. J. 471, 385399.CrossRefGoogle Scholar
Delbende, I. & Rossi, M. 2009 The dynamics of a viscous dipole. Phys. Fluids 21, 073605.CrossRefGoogle Scholar
Dritschel, D. G. 1995 A general theory for two-dimensional vortex interactions. J. Fluid Mech. 293, 269303.CrossRefGoogle Scholar
van Geffen, J. H. J. M. & van Heijst, G. J. F. 1998 Viscous evolution of 2D dipolar vortices. Fluid Dyn. Res. 22, 191213.CrossRefGoogle Scholar
Holloway, G. 2004 From classical to statistical ocean dynamics. Surv. Geophys. 25, 203219.Google Scholar
Juul Rasmussen, J., Hesthaven, J. S., Lynev, J. P., Nielsen, A. H. & Schmidt, M. R. 1996 Dipolar vortices in two-dimensional flows. Math. Comput. Simul. 40, 207221.CrossRefGoogle Scholar
Kessler, D. A., Koplik, J. & Levine, H. 1988 Pattern selection in fingered growth phenomena. Adv. Phys. 37, 255339.CrossRefGoogle Scholar
Khvoles, R., Berson, D. & Kizner, Z. 2005 The structure and evolution of barotropic elliptical modons. J. Fluid Mech. 530, 130.Google Scholar
Kizner, Z., Berson, D. & Khvoles, R. 2002 Baroclinic modon equilibria on the beta-plane: stability and transitions. J. Fluid Mech. 468, 239270.CrossRefGoogle Scholar
Kizner, Z., Berson, D. & Khvoles, R. 2003 Noncircular baroclinic beta-plane modons: constructing stationary solutions. J. Fluid Mech. 489, 199228.CrossRefGoogle Scholar
Kizner, Z. & Khvoles, R. 2004 Two variations on the theme of Lamb–Chaplygin: supersmooth dipole and rotating multipoles. Reg. Chaot. Dyn. 9, 509518.CrossRefGoogle Scholar
Kizner, Z. & Reznik, G. 2010 Localized dipoles: from 2D to rotating shallow water. Theor. Comput. Fluid Dyn. 24, 101110.CrossRefGoogle Scholar
Kraichnan, R. H. 1967 Inertial ranges in two-dimensional turbulence. Phys. Fluids 10, 14171423.CrossRefGoogle Scholar
Lamb, H. 1895 Hydrodynamics, 2nd edn.Cambridge University Press.CrossRefGoogle Scholar
Leith, C. E. 1984 Minimum enstrophy vortices. Phys. Fluids 27, 13881395.CrossRefGoogle Scholar
Meleshko, V. V. & van Heijst, G. J. F. 1994 On Chaplygin's investigations of two-dimensional vortex structures in an inviscid fluid. J. Fluid Mech. 272, 157182.CrossRefGoogle Scholar
Nielsen, A. H. & Juul Rasmussen, J. 1996 Formation and temporal evolution of the Lamb dipole. Phys. Fluids 9, 982991.CrossRefGoogle Scholar
Pierrehumbert, R. T. 1980 A family of steady, translating vortex pairs with distributed vorticity. J. Fluid Mech. 99, 129144.Google Scholar
Sipp, D., Jacquin, L. & Cossi, C. 2000 Self-adaptation and viscous selection in concentrated two-dimensional vortex dipoles. Phys. Fluids 12, 245248.CrossRefGoogle Scholar
Swaters, G. 1988 Viscous modulation of the Lamb dipole vortex. Phys. Fluids 31, 27452747.CrossRefGoogle Scholar
Swaters, G. 1991 Dynamical characteristics of decaying Lamb couples. ZAMP 42, 110121.Google Scholar
Trieling, R., Santbergen, R., van Heijst, G. J. & Kizner, Z. 2010 Barotropic elliptical dipoles on a rotating fluid. Theor. Comput. Fluid Dyn. 24, 111115.CrossRefGoogle Scholar