Passive and active electromagnetic stabilization of free-surface liquid metal flows

S. M. H. Mirhoseini - R. R. Diaz-Pacheco - F. A. Volpe

Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA

Abstract
Free-surface liquid metal flows tend to be uneven due to instabilities and other effects. Some applications, however, require constant, uniform liquid metal thickness. This is, for example, the case of liquid walls in nuclear fusion reactors. With this motivation, here we present experimental results on the stabilization of a free-surface flow of Galinstan. The flow was sustained by an electromagnetic induction pump featuring rotating permanent magnets. Evidence is reported of the flowing Galinstan layer becoming flatter in the presence of a sufficiently strong magnetic field, either alone (passive stabilization) or in combination with an electrical current passing through the liquid metal (active stabilization). The results are interpreted in terms of an effective viscosity and effective gravity, respectively. Figs 8, Refs 19.