dorsal/arxiv
View SchemaOn the inverse cascade of magnetic helicity
| Authors | Alexandros Alexakis, Pablo Mininni, Annick Pouquet |
|---|---|
| Categories | |
| ArXiv ID | physics/0509069 |
| URL | https://arxiv.org/abs/physics/0509069 |
| DOI | 10.1086/500082 |
Abstract
We study the inverse cascade of magnetic helicity in conducting fluids by investigating the detailed transfer of helicity between different spherical shells in Fourier space in direct numerical simulations of three-dimensional magnetohydrodynamics (MHD). Two different numerical simulations are used, one where the system is forced with an electromotive force in the induction equation, and one in which the system is forced mechanically with an ABC flow and the magnetic field is solely sustained by a dynamo action. The magnetic helicity cascade at the initial stages of both simulations is observed to be inverse and local (in scale space) in the large scales, and direct and local in the small scales. When saturation is approached most of the helicity is concentrated in the large scales and the cascade is non-local. Helicity is transfered directly from the forced scales to the largest scales. At the same time, a smaller in amplitude direct cascade is observed from the largest scale to small scales.
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"abstract": "We study the inverse cascade of magnetic helicity in conducting fluids by\ninvestigating the detailed transfer of helicity between different spherical\nshells in Fourier space in direct numerical simulations of three-dimensional\nmagnetohydrodynamics (MHD). Two different numerical simulations are used, one\nwhere the system is forced with an electromotive force in the induction\nequation, and one in which the system is forced mechanically with an ABC flow\nand the magnetic field is solely sustained by a dynamo action. The magnetic\nhelicity cascade at the initial stages of both simulations is observed to be\ninverse and local (in scale space) in the large scales, and direct and local in\nthe small scales. When saturation is approached most of the helicity is\nconcentrated in the large scales and the cascade is non-local. Helicity is\ntransfered directly from the forced scales to the largest scales. At the same\ntime, a smaller in amplitude direct cascade is observed from the largest scale\nto small scales.",
"arxiv_id": "physics/0509069",
"authors": [
"Alexandros Alexakis",
"Pablo Mininni",
"Annick Pouquet"
],
"categories": [
"physics.plasm-ph",
"physics.flu-dyn"
],
"doi": "10.1086/500082",
"title": "On the inverse cascade of magnetic helicity",
"url": "https://arxiv.org/abs/physics/0509069"
},
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