Capillary instability of the cylindrical interface between ferrofluids in a magnetic field with circular field lines

Capillary breakup of a viscous magnetic fluid layer subjected to a gradient magnetic field under hydroweightlessness is studied within the linear theory. The cylinder surface of a current-carrying conductor serves as the inner boundary of the layer. The outer boundary of the layer is the coaxial interface with an immiscible nonviscous fluid of lower permeability. The particular subject of investigation is the effect of the relative thickness of the layer and that of the magnetic Bond number on the characteristic time of growth of the fastest-increasing harmonic and on the size of droplets forming under the ultimate conditions of capillary breakup (i.e., at large and small Ohnesorge numbers).