arXiv subjects

Dirk Rannacher

Publications and source records attributed to Dirk Rannacher.

2 recordsLinked to original sources

arXiv2006

Influence of surface tension on the conical miniscus of a magnetic fluid in the field of a current-carrying wire

We study the influence of surface tension on the shape of the conical miniscus built up by a magnetic fluid surrounding a current-carrying wire. Minimization of the total energy of the system leads to a singular second order boundary value problem for the function $ζ(r)$ describing the axially symmetric shape of the free surface. An appropriate transformation regularizes the problem and allows a straightforward numerical solution. We also study the effects a superimposed second liquid, a nonlinear magnetization law of the magnetic fluid, and the influence of the diameter of the wire on the free surface profile.

cond-mat.mtrl-sci↗

arXiv2004

Double Rosensweig instability in a ferrofluid sandwich structure

We consider a horizontal ferrofluid layer sandwiched between two layers of immiscible non-magnetic fluids. In a sufficiently strong vertical magnetic field the flat interfaces between magnetic and non-magnetic fluids become unstable to the formation of peaks. We theoretically investigate the interplay between these two instabilities for different combinations of the parameters of the fluids and analyze the evolving interfacial patterns. We also estimate the critical magnetic field strength at which thin layers disintegrate into an ordered array of individual drops.

cond-mat.mtrl-sci↗