Turbulent magnetic Prandtl numbers obtained with MHD Taylor-Couette flow experiments

Simple item page
dc.creatorGellert, M.
dc.creatorRuediger, G.
dc.date2008-09-19
dc.date.accessioned2026-07-07T10:04:01Z
dc.date.available2026-07-07T10:04:01Z
dc.descriptionThe stability problem of MHD Taylor-Couette flows with toroidal magnetic fields is considered in dependence on the magnetic Prandtl number. Only the most uniform (but not current-free) field with B\_in = B\_out has been considered. For high enough Hartmann numbers the toroidal field is always unstable. Rigid rotation, however, stabilizes the magnetic (kink-)instability. The axial current which drives the instability is reduced by the electromotive force induced by the instability itself. Numerical simulations are presented to probe this effect as a possibility to measure the turbulent conductivity in a laboratory. It is shown numerically that in a sodium experiment (without rotation) an eddy diffusivity 4 times the molecular diffusivity appears resulting in a potential difference of ~34 mV/m. If the cylinders are rotating then also the eddy viscosity can be measured. Nonlinear simulations of the instability lead to a turbulent magnetic Prandtl number of 2.1 for a molecular magnetic Prandtl number of 0.01. The trend goes to higher values for smaller Pm.
dc.description5 pages, 5 figures, preprint
dc.identifierhttps://arxiv.org/abs/0809.3345
dc.identifierhttp://arxiv.org/abs/0809.3345
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/169510
dc.subjectAstrophysics
dc.titleTurbulent magnetic Prandtl numbers obtained with MHD Taylor-Couette flow experiments
dc.typetext

Files

Collections

arXiv