Local shell-to-shell energy transfer via nonlocal interactions in fluid turbulence

Inverse energy cascade in nonlocal helical shell models of turbulence.

Following the exact decomposition in eigenstates of helicity for the Navier-Stokes equations in Fourier space [F. Waleffe, Phys. Fluids A 4, 350 (1992)], we introduce a modified version of helical shell models for turbulence with nonlocal triadic interactions. By using both an analytical argument and numerical simulation, we show that there exists a class of models, with a specific helical stru...

Shell-to-shell energy transfer in magnetohydrodynamics. I. Steady state turbulence.

We investigate the transfer of energy from large scales to small scales in fully developed forced three-dimensional magnetohydrodynamics (MHD) turbulence by analyzing the results of direct numerical simulations in the absence of an externally imposed uniform magnetic field. Our results show that the transfer of kinetic energy from large scales to kinetic energy at smaller scales and the transfe...

Shell-to-shell energy transfer in magnetohydrodynamics. II. Kinematic dynamo.

We study the transfer of energy between different scales for forced three-dimensional magnetohydrodynamics turbulent flows in the kinematic dynamo regime. Two different forces are examined: a nonhelical Taylor-Green flow with magnetic Prandtl number P(M) = 0.4 and a helical ABC flow with P(M) = 1. This analysis allows us to examine which scales of the velocity flow are responsible for dynamo ac...

Shell to shell energy transfer in magnetohydrodynamic dynamo simulations

We study the transfer of energy between different scales for forced three-dimensional MHD turbulent flows in the kinematic dynamo regime. Two different forces are examined: a non-helical Taylor Green flow with magnetic Prandtl number PM = 0.4, and a helical ABC flow with PM = 1. This analysis allows us to examine which scales of the velocity flow are responsible for dynamo action, and which sca...

A non-local shell model of hydrodynamic and magnetohydrodynamic turbulence