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On the genesis of quasi-steady vortices in a rotating turbulent flow

Published online by Cambridge University Press:  21 April 2006

Mathieu Mory
Affiliation:
Institut de Mécanique de Grenoble, Domaine Universitaire, BP 68, 38402 Saint Martin d'Hères Cédex, France
Philippe Caperan
Affiliation:
Institut de Mécanique de Grenoble, Domaine Universitaire, BP 68, 38402 Saint Martin d'Hères Cédex, France

Abstract

Turbulent flows subjected to rotation display vortices parallel to the rotation axis and exhibiting a long timescale compared to the turbulent turnover time and the rotation period. A similar flow pattern is observed arising from the thermal instability in a rotating fluid. We demonstrate the analogy between turbulence and thermal convection in a rotating fluid. A basic quasi-geostrophic turbulent flow is considered which is forced at the bottom of the layer by a stochastic component of velocity parallel to the rotation axis. The turbulent basic state has no mean flow and the gradient along the rotation axis of the turbulent kinetic energy −∂z〈ω2〉 is analogous to the mean temperature profile in thermal convection. The linear perturbation equations of this basic turbulent state are given, where the thermal diffusion equation is replaced by the turbulent kinetic energy equation. Using a simple closure of this equation the model demonstrates the occurrence of an instability when the Reynolds number exceeds a critical value. Marginal stability curves are deduced by numerical integration of the perturbation equations. The results show order-of-magnitude agreement with laboratory experiments.

Type
Research Article
Copyright
© 1987 Cambridge University Press

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References

Barcilon, A., Brindley, J., Lessen, M. & Mobbs, F. R. 1979 J. Fluid Mech. 94, 453463.
Bretherton, F. P. & Turner, J. S. 1968 J. Fluid Mech. 32, 449464.
Browand, F. K. & Hopfinger, E. J. 1985 In IMA Conf. Proc. Cambridge, 1983. Clarendon.
Chandrasekhar, S. 1961 Hydrodynamics and Hydromagnetics Stability. Dover.
De Verdière, A. Colin 1980 Geophys. Astrophys. Fluid Dyn. 15, 213251.
Dickinson, S. C. & Long, R. R. 1982 J. Fluid Mech. 126, 315333.
Hopfinger, E. J., Browand, F. K. & Gagne, Y. 1982 J. Fluid Mech. 125, 505534.
Ivey, G. N. & Corcos, G. M. 1982 J. Fluid Mech. 121, 126.
Lessen, M. 1978 J. Fluid Mech. 88, 535540.
Lundgren, T. S. 1985 J. Fluid Mech. 155, 381412.
Mcewan, A. D. 1976 Nature 260, 126128.
Malkus, W. V. R. 1956 J. Fluid Mech. 1, 521539.
Malkus, W. V. R. 1978 J. Fluid Mech. 90, 401414.
Maxworthy, T., Hopfinger, E. J. & Redekopp, L. 1985 J. Fluid Mech. 151, 141165.
Monin, A. S. & Yaglom, A. M. 1965 Statistical Fluid Mechanics. MIT Press.
Morse, P. M. & Feshbach, H. 1953 Methods of Theoretical Physics. McGraw Hill.
Mory, M. & Hopfinger, E. J. 1985 In Macroscopic Modelling of Turbulent Flows, Lecture Notes in Physics, vol. 230, 230.
Mory, M. & Hopfinger, E. J. 1986 Phys. Fluids 29, 21402146.
Nakagawa, Y. & Frenzen, P. 1955 Tellus 1, 121.
Pedlosky, J. 1979 Geophysical Fluid Dynamics. Springer.
Rhines, P. B. 1979 Ann. Rev. Fluid Mech. 11, 401441.
Scorer, R. S. 1966 Science 2, 4652.
Spiegel, E. A. 1961 In Mecanique de la Turbulence, p. 181. Marseille: CNRS.
Thompson, R. O. R. Y. 1979 Geophys. Astrophys. Fluid Dyn. 12, 221223.
Veronis, G. 1959 J. Fluid Mech. 5, 401435.
Veronis, G. 1967 Tellus 19, 326335.