141 citations · 572 across the 31 of their papers we have counts for
9 papers · 1 filter
Deciphering solar turbulence from sunspots records
Franck Plunian, Graeme Sarson, Rodion Stepanov
It is generally believed that sunspots are the emergent part of magnetic flux tubes in the solar interior. These tubes are created at the base of the convection zone and rise to th…
Generation of axisymmetric modes in cylindrical kinematic mean-field dynamos of VKS type
A. Giesecke, C. Nore, F. Plunian +6
In an attempt to understand why the dominating magnetic field observed in the von-Kármán-Sodium (VKS) dynamo experiment is axisymmetric, we investigate in the present paper the abi…
Cylindrical anisotropic dynamos
R. Avalos-Zuñiga, M. Xu, F. Stefani +2
We explore the influence of geometry variations on the structure and the time-dependence of the magnetic field that is induced by kinematic dynamos in a finite cylinder. Th…
Harmonic and subharmonic solutions of the Roberts dynamo problem. Application to the Karlsruhe experiment
F. Plunian, K. -H. Radler
Two different approaches to the Roberts dynamo problem are considered. Firstly, the equations governing the magnetic field are specified to both harmonic and subharmonic solutions…
Influence of electromagnetic boundary conditions onto the onset of dynamo action in laboratory experiments
R. Avalos-Zuniga, F. Plunian
We study the onset of dynamo action of the Riga and Karlsruhe experiments with the addition of an external wall, the electro-magnetic properties of which being different from those…
An optimal scale separation for a dynamo experiment
Franck Plunian
Scale separation between the flow and the magnetic field is a common feature of natural dynamos. It has also been used in the Karlsruhe sodium experiment in which the scale of the…
Rossby waves and -effect
R. Avalos-Zuniga, F. Plunian, K. H. R\" Adler
Rossby waves drifting in the azimuthal direction are a common feature at the onset of thermal convective instability in a rapidly rotating spherical shell. They can also result fro…
Oscillating Ponomarenko dynamo in the highly conducting limit
Marine Peyrot, Andrew Gilbert, Franck Plunian
This paper considers dynamo action in smooth helical flows in cylindrical geometry, otherwise known as Ponomarenko dynamos, with periodic time dependence. An asymptotic framework i…
Homopolar oscillating-disc dynamo driven by parametric resonance
Jānis Priede, Raúl Avalos-Zúñiga, Franck Plunian
We use a simple model of Bullard-type disc dynamo, in which the disc rotation rate is subject to harmonic oscillations, to analyze the generation of magnetic field by the parametri…