Chaotic dynamos generated by a turbulent flow of liquid sodium

Florent Ravelet (1) , Michaël Berhanu (2) , Romain Monchaux (1) , Sébastien Aumaître (2) , Arnaud Chiffaudel (1) , François Daviaud (1) , Bérengère Dubrulle (1) , Mickaël Bourgoin (3) , Philippe Odier (4) , Jean-François Pinton (4) , Nicolas Plihon (4) , Romain Volk (4) , Stéphan Fauve (2) , Nicolas Mordant (2) , François Pétrélis (2)

1 SPEC - UMR3680 - Service de physique de l'état condensé
2 LPS - Laboratoire de Physique Statistique de l'ENS
3 LEGI - Laboratoire des Écoulements Géophysiques et Industriels [Grenoble]
4 Phys-ENS - Laboratoire de Physique de l'ENS Lyon

We report the observation of several dynamical regimes of the magnetic field generated by a turbulent flow of liquid sodium (VKS experiment). Stationary dynamos, transitions to relaxation cycles or to intermittent bursts, and random field reversals occur in a fairly small range of parameters. Large scale dynamics of the magnetic field result from the interactions of a few modes. The low dimensional nature of these dynamics is not smeared out by the very strong turbulent fluctuations of the flow.

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Florent Ravelet, Michaël Berhanu, Romain Monchaux, Sébastien Aumaître, Arnaud Chiffaudel, et al.. Chaotic dynamos generated by a turbulent flow of liquid sodium. Physical Review Letters, 2008, 101 (7), pp.074502. ⟨10.1103/PhysRevLett.101.074502⟩. ⟨hal-00492315⟩