Interfacial deformation and jetting of a magnetic fluid
Abstract
An attractive technique for forming and collecting aggregates of magnetic material at a liquid--air interface by an applied magnetic field gradient was recently addressed theoretically and experimentally [Soft Matter, (9) 2013, 8600-8608]: when the magnetic field is weak, the deflection of the liquid--air interface has a steady shape, while for sufficiently strong fields, the interface destabilizes and forms a jet that extracts magnetic material. Motivated by this work, we develop a numerical model for the closely related problem of solving two-phase Navier--Stokes equations coupled with the static Maxwell equations. We computationally model the forces generated by a magnetic field gradient produced by a permanent magnet and so determine the interfacial deflection of a magnetic fluid (a pure ferrofluid system) and the transition into a jet. We analyze the shape of the liquid--air interface during the deformation stage and the critical magnet distance for which the static interface transitions into a jet. We draw conclusions on the ability of our numerical model to predict the large interfacial deformation and the consequent jetting, free of any fitting parameter.
Keywords
Cite
@article{arxiv.1501.01000,
title = {Interfacial deformation and jetting of a magnetic fluid},
author = {Shahriar Afkhami and Linda J. Cummings and Ian M. Griffiths},
journal= {arXiv preprint arXiv:1501.01000},
year = {2015}
}