Eur. Phys. J. E (2018) 41: 4
https://doi.org/10.1140/epje/i2018-11612-1

Regular Article

Nonuniversal behaviour of helical two-dimensional three-component turbulence

¹ Department of Physics and INFN, University of Rome “Tor Vergata”, Via della Ricerca Scientifica 1, 00133, Rome, Italy
² Fachbereich Physik, Philipps-Universität Marburg, Renthof 6, 35032, Marburg, Germany

^* e-mail: moritz.linkmann@physik.uni-marburg.de

Received: 29 September 2017
Accepted: 21 December 2017
Published online: 15 January 2018

Abstract

The dynamics of two-dimensional three-component (2D3C) flows is relevant to describe the long-time evolution of strongly rotating flows and/or of conducting fluids with a strong mean magnetic field. We show that in the presence of a strong helical forcing, the out-of-plane component ceases to behave as a passive advected quantity and develops a nontrivial dynamics which deeply changes its large-scale properties. We show that a small-scale helicity injection correlates the input on the 2D component with the one on the out-of-plane component. As a result, the third component develops a nontrivial energy transfer. The latter is mediated by homochiral triads, confirming the strong 3D nature of the leading dynamical interactions. In conclusion, we show that the out-of-plane component in a 2D3C flow enjoys strong nonuniversal properties as a function of the degree of mirror symmetry of the small-scale forcing.