Shell models of magnetohydrodynamic turbulence

Shell Models for Magnetohydrodynamic Turbulence

We review the main properties of shell models for magnetohydrodynamic (MHD) turbulence. After a brief account on shell models with nearest neighbour interactions, the paper focuses on the most recent results concerning dynamical properties and intermittency of a model which is a generalization to MHD of the Gledzer-Yamada-Okhitani (GOY) model for hydrodynamic. Applications to astrophysical prob...

A non-local shell model of hydrodynamic and magnetohydrodynamic turbulence

Multiscaling in Models of Magnetohydrodynamic Turbulence

From a numerical study of the magnetohydrodynamic (MHD) equations we show, for the first time in three dimensions sd ­ 3d, that velocity and magnetic-field structure functions exhibit multiscaling, extended self-similarity (ESS), and generalized extended self-similarity (GESS). We propose a new shell model for homogeneous and isotropic MHD turbulence, which preserves all the invariants of ideal...

Shell Models of Superfluid Turbulence

Superfluid helium consists of two inter-penetrating fluids, a viscous normal fluid and an inviscid superfluid, coupled by a mutual friction. We develop a two-fluid shell model to study superfluid turbulence and investigate the energy spectra and the balance of fluxes between the two fluids in a steady state. At sufficiently low temperatures a ’bottle-neck’ develops at high wavenumbers suggestin...

Regularity of inviscid shell models of turbulence.

In this paper we continue the analytical study of the sabra shell model of energy turbulent cascade. We prove the global existence of weak solutions of the inviscid sabra shell model, and show that these solutions are unique for some short interval of time. In addition, we prove that the solutions conserve energy, provided that the components of the solution satisfy /u(n)/ <or= Ck(n)(-1/3)[squa...