- Letter
Nonlinear turbulent dynamo induced by fluctuations of the Lorentz force
Phys. Rev. E 104, L053102 – Published 15 November, 2021
DOI: https://doi.org/10.1103/PhysRevE.104.L053102
Abstract
The turbulent hydromagnetic dynamo is a process of magnetic field amplification by a chaotic flow of an electrically conducting fluid, responsible for generation of the magnetic fields of planets and stars. Here we demonstrate a curious effect of the Lorentz force, which can act to intensify the magnetic fields, counterintuitively in light of the Lenz law according to which the Lorentz force acts to retard motions and saturate the dynamo-induced magnetic field. However, the net effect of its small-scale fluctuations in a turbulent flow is far from obvious and it is shown that it can lead to amplification rather than saturation of the magnetic energy through creation of negative turbulent diffusivity.
Physics Subject Headings (PhySH)
Corrections
3 February, 2022
Correction: Minor errors in Eqs. (12c) and (12d) as well as in an equation in the second sentence below Eq. (16) have been fixed.
