author = "Pouquet, Annick"

Found 27 documents, displaying page 1 of 3

## A review of the possible role of constraints in MHD turbulence

Author(s) : Pouquet, Annick
Description : A review of some of the issues that have arisen over the years concerning the energy distribution among scales for magnetohydrodynamics (MHD) turbulence is given here. A variety of tools are employed to that effect, and a central role is played by taking into consideration the ideal (non-dissipati...
Repository : arXiv
Language(s) : Undetermined

## An alternative interpretation for the Holm "alpha model"

Description : By re-interpreting a recent successful closure procedure in terms of local spatial averaging and the neglect of fluctuations about that average, it is shown how the results of that closure scheme (the ''alpha model'') may be more simply derived. , Comment: To appear in Physics of Fluids (2002)
Repository : arXiv
Language(s) : Undetermined

## On spectral scaling laws for incompressible anisotropic MHD turbulence

Description : A heuristic model is given for anisotropic magnetohydrodynamics (MHD) turbulence in the presence of a uniform external magnetic field $B_0 {\bf {\hat e}_{\pa}}$. The model is valid for both moderate and strong $B_0$ and is able to describe both the strong and weak wave turbulence regimes as well a...
Repository : arXiv
Language(s) : Undetermined

## On the inverse cascade of magnetic helicity

Description : We study the inverse cascade of magnetic helicity in conducting fluids by investigating the detailed transfer of helicity between different spherical shells in Fourier space in direct numerical simulations of three-dimensional magnetohydrodynamics (MHD). Two different numerical simulations are use...
Repository : arXiv
Language(s) : Undetermined

## Spectral Modeling of Turbulent Flows and the Role of Helicity

Description : We present a new version of a dynamical spectral model for Large Eddy Simulation based on the Eddy Damped Quasi Normal Markovian approximation \cite{sao,chollet_lesieur}. Three distinct modifications are implemented and tested. On the one hand, whereas in current approaches, a Kolmogorov-like energy...
Repository : HAL - Hyper Article on Line
Language(s) : English

## On the emergence of helicity in rotating stratified turbulence

Description : We perform numerical simulations of decaying rotating stratified turbulence and show, in the Boussinesq framework, that helicity (velocity-vorticity correlation), as observed in super-cell storms and hurricanes, is spontaneously created due to an interplay between buoyancy and rotation common to l...
Repository : arXiv
Language(s) : Undetermined

## Geophysical-astrophysical spectral-element adaptive refinement (GASpAR): Object-oriented h-adaptive code for geophysical fluid dynamics simulation

Description : We present an object-oriented geophysical and astrophysical spectral-element adaptive refinement (GASpAR) code for application to turbulent flows. Like most spectral-element codes, GASpAR combines finite-element efficiency with spectral-method accuracy. It is also designed to be flexible enough fo...
Repository : arXiv
Language(s) : Undetermined

## Shell to shell energy transfer in MHD, Part I: steady state turbulence

Description : We investigate the transfer of energy from large scales to small scales in fully developed forced three-dimensional 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 ...
Repository : arXiv
Language(s) : Undetermined

## Shell to shell energy transfer in MHD, Part II: Kinematic dynamo

Description : 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 P_M=0.4, and a helical ABC flow with P_M=1. This analysis allows...
Repository : arXiv
Language(s) : Undetermined

## Cancellation exponent and multifractal structure in two-dimensional magnetohydrodynamics: direct numerical simulations and Lagrangian averaged modeling

Description : We present direct numerical simulations and Lagrangian averaged (also known as alpha-model) simulations of forced and free decaying magnetohydrodynamic turbulence in two dimensions. The statistics of sign cancellations of the current at small scales is studied using both the cancellation exponent ...
Repository : arXiv
Language(s) : Undetermined

Found 27 documents, displaying page 1 of 3