The magneto-rotational instability near threshold: spatio-temporal amplitude equation and saturation
Abstract
We show, by means of a perturbative weakly nonlinear analysis, that the axisymmetric magneto-rotational instability (MRI) in a magnetic Taylor-Couette (mTC) flow in a thin-gap gives rise, for very small magnetic Prandtl numbers (P_m), to a real Ginzburg-Landau equation for the disturbance amplitude. The saturation amplitude A_s is found to scale in this regime as P^\delta, with 1/2<\delta<2/3 (depending on the boundary conditions adopted). The asymptotic results are shown to comply with numerical calculations performed by using a spectral code. They suggest that the transport due to the nonlinearly developed MRI may be vanishingly small for P_m << 1.
Keywords
Cite
@article{arxiv.0801.1637,
title = {The magneto-rotational instability near threshold: spatio-temporal amplitude equation and saturation},
author = {O. Regev},
journal= {arXiv preprint arXiv:0801.1637},
year = {2015}
}
Comments
To appear in conference proceedings 'European Astronomical Society Publications series', EDP Sciences