The Impact of a Vertically Travelling Magnetic Field on the Flow in a Cylindrical Liquid Metal Bubble Plume

This article describes laboratory experiments for the investigations of flow structures and related transport processes in liquid metal bubbly flows under the influence of a traveling magnetic field (TMF). The melt flow is driven by central gas injection into a cylindrical container filled with the low-melting-point alloy GaInSn. The velocity fields of both the liquid and the gaseous phase were measured nonintrusively using the ultrasound Doppler method. Depending on the traveling direction of the magnetic field, the TMF mainly imposes either a concurrent flow or counterflow with respect to the original bubble-driven circulation. In general, the application of a downward TMF significantly increases the liquid velocity all over the fluid volume. An upward TMF gives rise to the more complex structures of the velocity field resulting in alternately arranged upstream and downstream regions. Both the upward and downward TMF promote the occurrence of nonsteady motions with distinct velocity fluctuations leading to an intensification of related transport processes in the melt and providing the perspective of enhanced mixing efficiencies.