Electrocapillary instability of magnetic fluid peak

TL;DR

This study investigates how electric and magnetic fields influence the electrocapillary instability of magnetic fluid peaks, revealing the conditions for instability, hysteresis effects, and pulsation frequencies through experimental measurements.

Contribution

It provides new experimental data on the effects of magnetic and electric fields on magnetic fluid peak instability, including critical thresholds and hysteresis behavior.

Findings

Magnetic field influences the regularity and development of electrocapillary instability.

Critical electric and magnetic field strengths depend on peak size.

Hysteresis observed in charged drops emission thresholds.

Abstract

The paper presents an experimental study of the capillary electrostatic instability occurring under effect of a constant electric field on a magnetic fluid individual peak. The peaks under study occur at disintegration of a magnetic fluid layer applied on a flat electrode surface under effect of a perpendicular magnetic field. The electrocapillary instability shows itself as an emission of charged drops jets from the peak point in direction of the opposing electrode. The charged drops emission repeats periodically and results in the peak shape pulsations. It is shown that a magnetic field affects the electrocapillary instability occurrence regularities and can stimulate its development. The critical electric and magnetic field strengths at which the instability occurs have been measured; their dependence on the peak size is shown. The hysteresis in the system has been studied; it consists in that the charged drops emission stops at a lesser electric (or magnetic) field strength than that of the initial occurrence. The peak pulsations frequency depending on the magnetic and electric field strengths and on the peak size has been measured.