Spherical Couette flow in a dipolar magnetic field

R. Hollerbach (1) , Elisabeth Canet (2) , Alexandre Fournier (2)

1 Department of Applied Mathematics
2 LGIT - Laboratoire de Géophysique Interne et Tectonophysique

We consider numerically the flow of an electrically conducting fluid in a differentially rotating spherical shell, in a dipolar magnetic field. For infinitesimal differential rotation the flow consists of a super-rotating region, concentrated on the particular field line View the MathML source just touching the outer sphere, in agreement with previous results. Finite differential rotation suppresses this super-rotation, and pushes it inward, toward the equator of the inner sphere. For sufficiently strong differential rotation the outer boundary layer becomes unstable, yielding time-dependent solutions. Adding an overall rotation suppresses these instabilities again. The results are in qualitative agreement with the DTS liquid sodium experiment.

Mots clés: Magnetohydrodynamics; Spherical Couette flow

R. Hollerbach, Elisabeth Canet, Alexandre Fournier. Spherical Couette flow in a dipolar magnetic field. European Journal of Mechanics - B/Fluids, 2007, 26 (6), pp.729 à 737. ⟨10.1016/j.euromechflu.2007.02.002⟩. ⟨insu-00346226⟩