Generation of a Magnetic Field by Dynamo Action in a Turbulent Flow of Liquid Sodium

2007/01/06 by Romain Monchaux, R. Monchaux, M. Berhanu +25 · 7 citations
Biochemistry, Genetics and Molecular Biology · Mathematics · Physics and Astronomy · #Condensed matter physics #Dynamo #Dynamo theory #Geomagnetism and Paleomagnetism Studies #Geometry #Magnetic Reynolds number #Magnetic and Electromagnetic Effects #Magnetic field #Mathematics #Mechanics #Physics #Reynolds number #Scaling #Solar and Space Plasma Dynamics #Turbulence #physics.flu-dyn

paper · pdf · doi:10.1103/physrevlett.98.044502

4 pages, 5 figures

arxiv created 2007/01/06 · openalex publication_date 2007/01/25 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We report the observation of dynamo action in the von Kármán sodium experiment, i.e., the generation of a magnetic field by a strongly turbulent swirling flow of liquid sodium. Both mean and fluctuating parts of the field are studied. The dynamo threshold corresponds to a magnetic Reynolds number R(m) approximately 30. A mean magnetic field of the order of 40 G is observed 30% above threshold at the flow lateral boundary. The rms fluctuations are larger than the corresponding mean value for two of the components. The scaling of the mean square magnetic field is compared to a prediction previously made for high Reynolds number flows.

Citations

• Critical Magnetic Prandtl Number for Small-Scale Dynamo
• Magnetic-Field Generation in Kolmogorov Turbulence
• Experimental Test for the Dynamo Theory of Earth and Stellar Magnetism
• Influence of electromagnetic boundary conditions onto the onset of dynamo action in laboratory experiments
• Effect of multiplicative noise on parametric instabilities
• Ambivalent effects of added layers on steady kinematic dynamos in cylindrical geometry: application to the VKS experiment

Cited by

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• Self-organization and symmetry-breaking in two-dimensional plasma turbulence
• Mechanisms for magnetic field generation in precessing cubes
• Slow Dynamics in a Turbulent von Kármán Swirling Flow
• Numerical simulations of dynamos generated in spherical Couette flows
• Finite dissipation and intermittency in magnetohydrodynamics