title: Controlling fingering instabilities in rotating ferrofluids.
abstract: We perform a detailed analytic and numerical study of the evolution of a ferrofluid drop confined to a rotating Hele-Shaw cell in the presence of an azimuthal magnetic field. Our results demonstrate that the centrifugally driven interfacial instabilities can be simply controlled with the use of a current-carrying wire. We compare an analytic linear analysis to our computational results and show that a number of observed features cannot be explained by linear theory alone, including a "diamond ring" instability that results when a droplet is nearly stabilized.
authors.affiliation: Department of Physics and Astronomy, Dickinson College, Carlisle, Pennsylvania 17013, USA.
authors.forename: David P
authors.initials: DP
authors.lastname: Jackson
authors.forename: José A
authors.initials: JA
authors.lastname: Miranda