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Updated: Jul 7, 2026
06:42
Magnetically Induced Rotating Rayleigh-Taylor Instability
Published on: March 3, 2017
Subcritical dynamo bifurcation in the Taylor-Green flow
Y Ponty1, J-P Laval, B Dubrulle
1Laboratoire Cassiopée, CNRS & Observatoire de la Côte d'Azur, Nice 06304, France.
Physical Review Letters
|February 1, 2008
Summary
Direct numerical simulations reveal subcritical dynamo generation in Taylor-Green flow. Hysteresis is linked to Lorentz force effects on hydrodynamics, with external fields potentially inducing dynamo transitions.
Area of Science:
- Magnetohydrodynamics
- Plasma Physics
- Fluid Dynamics
Background:
- Dynamo theory explains how celestial bodies generate magnetic fields.
- Understanding dynamo generation is crucial for astrophysics and geophysics.
- Taylor-Green flow provides a standard model for turbulent fluid dynamics.
Purpose of the Study:
- To investigate dynamo generation in a specific fluid flow.
- To characterize the bifurcation behavior of the dynamo.
- To explore the influence of hydrodynamic and external field effects on dynamo transitions.
Main Methods:
- Direct numerical simulations (DNS) were employed.
- Taylor-Green forcing was used to generate the fluid flow.
- Analysis of magnetic field geometry and hydrodynamic changes was performed.
Main Results:
- The dynamo bifurcation was found to be subcritical.
- Hysteretic behavior was observed and linked to Lorentz force effects.
- The geometry of the dynamo magnetic field was visualized.
- The possibility of inducing dynamo transitions with an external field was demonstrated.
Conclusions:
- The study provides detailed insights into subcritical dynamo generation.
- Lorentz forces play a significant role in the hysteretic behavior of dynamos.
- External fields offer a potential mechanism for controlling dynamo transitions.
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