arXiv subjects

D. Rannacher

Publications and source records attributed to D. Rannacher.

2 recordsLinked to original sources

arXiv2006

Suppressing the Rayleigh-Taylor instability with a rotating magnetic field

The Rayleigh-Taylor instability of a magnetic fluid superimposed on a non-magnetic liquid of lower density may be suppressed with the help of a spatially homogeneous magnetic field rotating in the plane of the undisturbed interface. Starting from the complete set of Navier-Stokes equations for both liquids a Floquet analysis is performed which consistently takes into account the viscosities of the fluids. Using experimentally relevant values of the parameters we suggest to use this stabilization mechanism to provide controlled initial conditions for an experimental investigation of the Rayleigh-Taylor instability.

physics.flu-dyn↗

arXiv2006

Cylindrical Korteweg-de Vries solitons on a ferrofluid surface

Linear and non-linear surface waves on a ferrofluid cylinder surrounding a current-carrying wire are investigated. Suppressing the Rayleigh-Plateau instability of the fluid column by the magnetic field of a sufficiently large current in the wire axis-symmetric surface deformations are shown to propagate without dispersion in the long wavelength limit. Using multiple scale perturbation theory the weakly non-linear regime may be described by a Korteweg-de Vries equation with coefficients depending on the magnetic field strength. For different values for the current in the wire hence different solutions such as hump or hole solitons may be generated. The possibility to observe these structures in experiments is also elucidated.

physics.flu-dyn↗