Conserving Local Magnetic Helicity in Numerical Simulations

Autor:	Zenati, Yossef, Vishniac, Ethan T.
Rok vydání:	2021
Předmět:	Physics - Plasma Physics Astrophysics - High Energy Astrophysical Phenomena Physics - Fluid Dynamics
Druh dokumentu:	Working Paper
Popis:	Magnetic helicity is robustly conserved in systems with very large magnetic Reynolds numbers, including most systems of astrophysical interest, and unlike kinetic and magnetic energy is not dissipated at small scales. This plays a major role in suppressing the kinematic large-scale dynamo and may also be responsible for driving the large-scale dynamo through the magnetic helicity flux. Numerical simulations of astrophysical systems typically lack sufficient resolution to enforce global magnetic helicity over several dynamical times. In these simulations, magnetic helicity is lost either through numerical errors or through the action of an unrealistically large resistivity. Errors in the internal distribution of magnetic helicity are equally important and typically larger. Here we propose an algorithm for enforcing strict local conservation of magnetic helicity in the Coulomb gauge in numerical simulations so that their evolution more closely approximates that of real systems. Comment: Accepted by ApJ
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/2106.06078 Zobrazit plný text záznamu View this record from Arxiv