Pumping velocity in homogeneous helical turbulence with shear

Igor Rogachevskii, Nathan Kleeorin, Petri J. Käpylä, Axel Brandenburg

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

Using different analytical methods (the quasilinear approach, the path-integral technique, and the tau-relaxation approximation) we develop a comprehensive mean-field theory for a pumping effect of the mean magnetic field in homogeneous nonrotating helical turbulence with imposed large-scale shear. The effective pumping velocity is proportional to the product of α effect and large-scale vorticity associated with the shear, and causes a separation of the toroidal and poloidal components of the mean magnetic field along the direction of the mean vorticity. We also perform direct numerical simulations of sheared turbulence in different ranges of hydrodynamic and magnetic Reynolds numbers and use a kinematic test-field method to determine the effective pumping velocity. The results of the numerical simulations are in agreement with the theoretical predictions.

Original languageEnglish
Article number056314
JournalPhysical Review E
Volume84
Issue number5
DOIs
StatePublished - 18 Nov 2011

ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Condensed Matter Physics

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