Reduction of velocity fluctuations in a turbulent flow of gallium by an external magnetic field

TL;DR

This study investigates how an external magnetic field suppresses velocity fluctuations in turbulent liquid Gallium flow, providing insights relevant to planetary and stellar magnetic dynamo processes.

Contribution

It demonstrates experimentally that increasing magnetic field strength reduces velocity fluctuations across all frequencies in turbulent Gallium flow.

Findings

Velocity fluctuations decrease with stronger magnetic fields

Magnetic field suppresses turbulence across all frequencies

Results relevant to planetary and stellar magnetic dynamos

Abstract

The magnetic field of planets or stars is generated by the motion of a conducting fluid through a dynamo instability. The saturation of the magnetic field occurs through the reaction of the Lorentz force on the flow. In relation to this phenomenon, we study the effect of a magnetic field on a turbulent flow of liquid Gallium. The measurement of electric potential differences provides a signal related to the local velocity fluctuations. We observe a reduction of velocity fluctuations at all frequencies in the spectrum when the magnetic field is increased.