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arXiv · 1706.00260

Dynamo enhancement and mode selection triggered by high magnetic permeability

Sophia Kreuzahler·Yannick Ponty·Nicolas Plihon·Holger Homann·Rainer Grauer
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Abstract

We present results from consistent dynamo simulations, where the electrically conducting and incompressible flow inside a cylinder vessel is forced by moving impellers numerically implemented by a penalization method. The numerical scheme models jumps of magnetic permeability for the solid impellers, resembling various configurations tested experimentally in the von-Karman Sodium experiment. The most striking experimental observations are reproduced in our set of simulations. In particular, we report on the existence of an axisymmetric dynamo mode, self-consistently generated when the magnetic permeability of the impellers exceeds a threshold. We describe a possible scenario involving both the turbulent flow in the vicinity of the impellers and the high magnetic permeability of the impellers.

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Sophia Kreuzahler, Yannick Ponty, Nicolas Plihon, Holger Homann, Rainer Grauer. 2017-06-01. Dynamo enhancement and mode selection triggered by high magnetic permeability. https://doi.org/10.1103/physrevlett.119.234501

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