Stability of the electrically induced flow between two hemispherical electrodes

V. Shatrov - G. Gerbeth

Helmholtz-Zentrum Dresden-Rossendorf, P.O. Box 510119, D-01314 Dresden, Germany

Abstract
The stability of the steady laminar flow driven by the meridional electromagnetic force due to an electric current from a hemispherical electrode to a hemispherical cavity surface is studied using a multi-domain pseudospectral method. The analysis is performed for a broad ratio of electrode and cavity radii. The most unstable azimuthal wave number is found as m=4, which differs from literature results for the flow in a cone with a point electrode, where the most unstable wave number was found as m=0. In the presence of an external uniform magnetic field the fluid rotates in the azimuthal direction. Already for a rather low strength of the external magnetic field the meridional flow in the main toroidal eddy changes its direction from counter-clockwise to clockwise. Tables 1, Figs 13, Refs 14.