The azimuthal magnetorotational instability (AMRI) |
| |
Authors: | G Rüdiger R Hollerbach M Gellert M Schultz |
| |
Institution: | 1. Department of Applied Mathematics, University of Leeds, Leeds, LS2 9JT, United Kingdom;2. Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam, Germany |
| |
Abstract: | We consider the flow of an electrically conducting fluid between differentially rotating cylinders, in the presence of an externally imposed current-free toroidal field B0(Rin/R) ê ? . It is known that the classical, axisymmetric magnetorotational instability does not exist for such a purely toroidal imposed field.We show here that a nonaxisymmetric magnetorotational instability does exist, having properties very similar to the axisymmetric magnetorotational instability in the presence of an axial field. In the nonlinear regime the magnetic energy of the perturbances is shifted (in the sense of an inverse cascade) to the axisymmetric mode rather than to the modes with m > 1. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) |
| |
Keywords: | instabilities magnetohydrodynamics (MHD) differential rotation |
|
|