Large-scale dynamics of magnetic helicity

Abstract

In this paper we investigate the dynamics of magnetic helicity in magnetohydrodynamic (MHD) turbulent flows focusing at scales larger than the forcing scale. Our results show a nonlocal inverse cascade of magnetic helicity, which occurs directly from the forcing scale into the largest scales of the magnetic field. We also observe that no magnetic helicity and no energy is transferred to an intermediate range of scales sufficiently smaller than the container size and larger than the forcing scale. Thus, the statistical properties of this range of scales, which increases with scale separation, is shown to be described to a large extent by the zero flux solutions of the absolute statistical equilibrium theory exhibited by the truncated ideal MHD equations.

6 pages, 5 figures, postprint version

References in corpus (5)

• Statistical equilibria of large scales in dissipative hydrodynamic turbulence
• Magnetic helicity and the evolution of decaying magnetohydrodynamic turbulence
• Helical mode interactions and spectral transfer processes in magnetohydrodynamic turbulence
• Self-organisation and non-linear dynamics in driven magnetohydrodynamic turbulent flows
• Optimal lengthscale for a turbulent dynamo

Cited by in corpus (10)

• Cascades and transitions in turbulent flows
• Reynolds-number dependence of the dimensionless dissipation rate in homogeneous magnetohydrodynamic turbulence
• Triad interactions and the bidirectional turbulent cascade of magnetic helicity
• Inverse cascade and magnetic vortices in kinetic Alfvén-wave turbulence
• Calculations for the Practical Applications of Quadratic Helicity in MHD
• Inverse cascade of hybrid helicity in $B\Omega$-MHD turbulence
• High-order finite-volume integration schemes for subsonic magnetohydrodynamics
• Inverse transfer of magnetic helicity in direct numerical simulations of compressible isothermal turbulence: scaling laws
• Partial invariants, large-scale dynamo action, and the inverse transfer of magnetic helicity
• Inverse transfer of magnetic helicity in direct numerical simulations of compressible isothermal turbulence: helical transfers