Dynamo action due to spatially dependent magnetic permeability
Laboratoire de Physique Statistique, École Normale Supérieure, CNRS, Université P. et M. Curie, Université Paris Diderot - 24 rue Lhomond, F-75005 Paris, France, EU
Accepted: 22 February 2012
We show that a simple flow of an electrically conducting fluid along a boundary with variable magnetic permeability can generate a magnetic field. An analytic study in the limit of weak permeability modulation allows to understand the mechanism of this dynamo and predicts scaling laws for the threshold. We discuss the possible contribution of this mechanism to the dynamo observed in the von Karman sodium experiment and we propose two flow configurations that could lead to the experimental observation of this new type of dynamo.
PACS: 91.25.Cw – Origins and models of the magnetic field; dynamo theories / 47.65.-d – Magnetohydrodynamics and electrohydrodynamics
© EPLA, 2012