Flow structures arising from melt stirring by means of modulated rotating magnetic fields

D. Räbiger¹ - S. Eckert¹ - G. Gerbeth¹ - S. Franke² - J. Czarske²

¹ Helmholtz Zentrum Dresden-Rossendorf (HZDR), PO. Box 510119 -- 01314 Dresden, Germany
² Technische Universitat Dresden, Helmholtzstrasse 18, 01069 Dresden, Germany

Abstract
We present an experimental study concerning measurements of the flow inside a liquid metal column exposed to a pulsed rotating magnetic field. A novel ultrasound Doppler system was used to measure two-dimensional velocity fields of the secondary flow in the radial-meridional plane. It employs an array of 25 transducer elements allowing a fast electronic traversing with concurrently high spatial and temporal resolution. The measurements revealed transient flow regimes showing distinct inertial oscillations and coherent vortex structures. The results demonstrate that the arising flow structure depends sensitively on the duration of the RMF pulses. Figs 8, Refs 13.