A nonlinear dynamo driven by rapidly rotating convection

Eun Jin Kim, David W. Hughes, Andrew M. Soward

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

In Kim et al. (Kim, E., Hughes, D.W. and Soward, A.M., "An investigation into high conductivity dynamo action driven by rotating convection", Geophys. Astrophys. Fluid Dynam. 91, 303-332 (1999).) we investigated kinematic dynamo action driven by rapidly rotating convection in a cylindrical annulus. Here we extend this work to consider self-consistent nonlinear dynamo action in which the back-reaction of the Lorentz force on the flow is taken into account. In particular, we investigate, as a function of magnetic Prandtl number, the evolution of an initially weak magnetic field in two different types of convective flow - one chaotic and the other integrable. On saturation, the latter shows a systematic dependence on the magnetic Prandtl number whereas the former appears not to. In addition, we show how, in keeping with the findings of Cattaneo et al. (Cattaneo, F., Hughes, D.W. and Kim, E., "Suppression of chaos in a simplified nonlinear dynamo model", Phys. Rev. Lett. 76, 2057-2060 (1996).), saturation of the growth of the magnetic field is brought about, for the originally chaotic flow, by a strong suppression of chaos.

Original languageEnglish
Pages (from-to)325-343
Number of pages19
JournalGeophysical and Astrophysical Fluid Dynamics
Volume98
Issue number4
DOIs
Publication statusPublished - 1 Aug 2004
Externally publishedYes

Keywords

  • Magnetic Prandtl number
  • Nonlinear dynamo
  • Rotating convection

ASJC Scopus subject areas

  • Computational Mechanics
  • Astronomy and Astrophysics
  • Geophysics
  • Mechanics of Materials
  • Geochemistry and Petrology

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