Experimental and numerical investigation of the instability of the electrovortex flow in hemispherical container

Experimental and numerical results on the effect of an external vertical magnetic field (MF) on the structure of the flow which occurs when an electric current passes through a conducting medium between two hemispheres are presented. The experiments on the velocity measurement were carried out on the eutectic alloy In-Ga-Sn with the unique fiber-optic transducers. The fiberoptic technique for measuring velocity is described. Results on influence of the axial external MF on the flow are presented. The boundary curve separating the one-vortex and two-vortices flow modes depending on the current values through the experimental setup and the external MF was obtained. These results can be used in electrometallurgy for a priori estimates of the flow structure in the direct-current-arc furnaces.