Bistability between a stationary and an oscillatory dynamo in a turbulent flow of liquid sodium

被引：25

作者：

Berhanu, M. ^{[1
]}

Gallet, B. ^{[1
]}

Monchaux, R. ^{[2
]}

Bourgoin, M. ^{[3
]}

Odier, Ph. ^{[3
]}

Pinton, J. -F. ^{[3
]}

Plihon, N. ^{[3
]}

Volk, R. ^{[3
]}

Fauve, S. ^{[1
]}

Mordant, N. ^{[1
]}

Petrelis, F. ^{[1
]}

Aumaitre, S. ^{[2
]}

Chiffaudel, A. ^{[2
]}

Daviaud, F. ^{[2
]}

Dubrulle, B. ^{[2
]}

Ravelet, F. ^{[2
]}

机构：

[1] Ecole Normale Super, Lab Phys Stat, CNRS, UMR8550, F-75005 Paris, France

[2] CEA Saclay, Serv Phys Etat Condense, CNRS, Direct Sci Mat,URA 2464, F-91191 Gif Sur Yvette, France

[3] Ecole Normale Super Lyon, Phys Lab, CNRS, UMR5672, F-69364 Lyon, France

来源：

JOURNAL OF FLUID MECHANICS | 2009年 / 641卷

关键词：

All Open Access; Green;

D O I：

10.1017/S0022112009991996

中图分类号：

O3 [力学];

学科分类号：

08 ; 0801 ;

摘要：

We report the first experimental observation of a bistable dynamo regime. A turbulent flow of liquid sodium is generated between two disks ill the von karman geometry (VKS experiment). When one disk is kept at rest, bistability is observed between a stationary and an oscillatory magnetic field. The stationary and oscillatory branches occur in the vicinity of a codimension-two bifurcation that results from the coupling between two modes of magnetic field. We present an experimental study or the two regimes and study in detail the region of bistability that we understand ill terms of dynamical system theory. Despite the very turbulent nature of the flow, the bifurcations of the magnetic field are correctly described by a low-dimensional model. In addition, the different regimes are robust; i.e. turbulent fluctuations do not drive any transition between the oscillatory and stationary states in the region of bistability.

引用

页码：217 / 226

页数：10

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