Ambiguity of the shape of a magnetic fluid drop in a magnetic field of a line conductor

Abstract

The behaviour of a magnetic fluid drop between solid cylinders determined by the current and the volume of the fluid is investigated. Hysteresis of the shape of such drop with the change of the magnetic field is found. Introduction. Phenomena of spontaneous change of the shape of the mag- netic fluid (MF) at a slow quasi-static change of system parameters are investigated in (1-3). Deformation of the MF drop along the wire with a passing current was investigated in (1). In (2) a jump of the MF to a permanent magnet, as it slow approaches the fluid, is studied. In (3) the behaviour of the free surface of a bound- less MF near the wire with the current is examined. There the phenomenon of rapid jump of the ascension height of the fluid has been predicted and observed in experiments. In the present paper, the behaviour of the drop between solid cylinders in dependence on the current and the volume of the fluid is investigated for all values. Hysteresis of the shape of such drop with the change of the magnetic field is found: the drop breaks up in two drops arising on the inner wire and the external cylinder, as the magnetic field increases to a critical value, and these two drops merge (or do not merge), as the magnetic field decreases from the critical value to zero.