Effect of alternating magnetic field on melt hydrodynamics in a cylindrical vessel with a free surface

Yu. M. Gelfgat - L. A. Gorbunov

Institute of Physics, Latvian University, Salaspils-1, LV-2169, Latvia

Abstract
The paper presents the results of theoretical and experimental study of hydrodynamics of melt with a free surface in a cylindrical vessel under the effect of rotating and alternating axisymmetric magnetic fields. It has been stated that with the increase of induction of a uniform rotating magnetic field there sequently occur four flow regimes in the fluid: a Stokes regime, a stable nonlinear regime, an oscillating nonlinear regime and again a stable nonlinear one. In a nonuniform rotating magnetic field, unstable regimes occur earlier, and their occurrence is caused by formation of free shear layers which divide areas with essentially different velocity values. In alternating magnetic fields, velocity structure is determined by the geometry of the location of the inductor with respect to the vessel, and it is characterized by one- or multi-contour flows in the melt. A free shear layer in the case of multi-contour flows causes the occurrence of unstable turbulent flows with a comparatively high level of velocity pulsations at rather small Reynolds numbers. The above features of the studied flows can be used to intensify heat and mass transfer processes in the practical application. Fig. 13, ref. 9.