Suppression of a laminar kinematic dynamo by a prescribed large-scale shear

Aditi Sood, Rainer Hollerbach, Eun Jin Kim

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

We numerically solve the magnetic induction equation in a spherical shell geometry, with a kinematically prescribed axisymmetric flow that consists of a superposition of a small-scale helical flow and a large-scale shear flow. The small-scale flow is chosen to be a local analog of the classical Roberts cells, consisting of strongly helical vortex rolls. The large-scale flow is a shearing motion in either the radial or the latitudinal directions. In the absence of large-scale shear, the small-scale flow operates very effectively as a dynamo, in agreement with previous results. Adding increasingly large shear flows strongly suppresses the dynamo efficiency, indicating that shear is not always a favorable ingredient in dynamo action.

Original languageEnglish
Article number425501
JournalJournal of Physics A: Mathematical and Theoretical
Volume49
Issue number42
DOIs
Publication statusPublished - 26 Sep 2016
Externally publishedYes

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Keywords

  • dynamo
  • dynamo quenching
  • large-scale shear
  • magnetic field
  • rotation rate
  • small-scale flow
  • suppression

ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Modelling and Simulation
  • Mathematical Physics
  • Physics and Astronomy(all)

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