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06:42
Magnetically Induced Rotating Rayleigh-Taylor Instability
Published on: March 3, 2017
Turbulent diamagnetism in flowing liquid sodium.
E J Spence1, M D Nornberg, C M Jacobson
1Department of Physics, University of Wisconsin-Madison, 1150 University Avenue, Madison, Wisconsin 53706, USA.
Physical Review Letters
|May 16, 2007
Summary
Turbulent flow in liquid sodium generates electric currents via a turbulent electromotive force, as described by Ohm's law. This effect creates a magnetic field opposing the applied field, comparable in magnitude to the field from the mean flow.
Area of Science:
- Magnetohydrodynamics
- Fluid dynamics
- Plasma physics
Background:
- Ohm's law describes the relationship between voltage, current, and resistance in conductive materials.
- Turbulent flows can induce complex electromagnetic phenomena.
- Understanding these interactions is crucial for astrophysical and industrial applications.
Purpose of the Study:
- To investigate the validity and manifestation of Ohm's law in a turbulent liquid sodium flow.
- To quantify the magnetic field generated by turbulent electromotive forces.
- To compare this fluctuation-driven field with the field induced by the mean flow.
Main Methods:
- Experimental setup involving a turbulent flow of liquid sodium.
- Application and measurement of an external magnetic field.
- Measurement of the resulting magnetic field and mean velocity field in a water model.
- Analysis of Ohm's law terms using the measured fields.
Main Results:
- Evidence of electric currents driven by a turbulent electromotive force was observed.
- These currents induced a diamagnetic effect, generating a magnetic field opposing the applied field.
- The magnitude of the fluctuation-driven magnetic field was found to be comparable to the field induced by the mean flow.
Conclusions:
- Turbulent electromotive forces play a significant role in generating magnetic fields in liquid sodium.
- Ohm's law in this context is influenced by turbulent fluctuations, not just mean flow properties.
- The findings have implications for understanding magnetic field generation in conductive fluids.
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