Minimalist large scale dynamo from shear-driven inhomogeneity

Autor:	Ebrahimi, F., Blackman, E. G.
Rok vydání:	2019
Předmět:	Physics - Fluid Dynamics Astrophysics - High Energy Astrophysical Phenomena Astrophysics - Solar and Stellar Astrophysics Physics - Plasma Physics
Druh dokumentu:	Working Paper
Popis:	We show that non-axisymmetric, non-helical perturbations in an unstratified shear flow produce a shear-plane averaged electromotive force (EMF) proportional to a spatially dependent kinetic helicity. This new "shear-driven $\alpha$-effect" can amplify shear-plane averaged magnetic fields, but is undiscoverable when invoking the homogeneity assumption for dynamo coefficients. It is a candidate mechanism underlying large scale field generation in astrophysical, laboratory, and simulated shear flows, and highlights the essentiality of correctly averaging dynamo coefficients and fields. Comment: 4 pages
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1902.04737 Zobrazit plný text záznamu View this record from Arxiv