Lagrangian model for the evolution of turbulent magnetic and passive scalar fields
Abstract
In this Brief Report we present an extension of the recent fluid deformation (RFD) closure introduced by Chevillard and Meneveau [L. Chevillard and C. Meneveau, Phys. Rev. Lett.PRLTAO0031900710.1103/PhysRevLett.97.174501 97, 174501 (2006)] which was developed for modeling the time evolution of Lagrangian fluctuations in incompressible NavierStokes turbulence. We apply the RFD closure to study the evolution of magnetic and passive scalar fluctuations. This comparison is especially interesting since the stretching term for the magnetic field and for the gradient of the passive scalar are similar but differ by a sign such that the effect of stretching and compression by the turbulent velocity field is reversed. Probability density functions (PDFs) of magnetic fluctuations and fluctuations of the gradient of the passive scalar obtained from the RFD closure are compared against PDFs obtained from direct numerical simulations.
 Publication:

Physical Review E
 Pub Date:
 January 2011
 DOI:
 10.1103/PhysRevE.83.017302
 arXiv:
 arXiv:1010.1598
 Bibcode:
 2011PhRvE..83a7302H
 Keywords:

 47.27.eb;
 47.10.g;
 02.50.Ey;
 52.30.Cv;
 Statistical theories and models;
 General theory in fluid dynamics;
 Stochastic processes;
 Magnetohydrodynamics;
 Physics  Plasma Physics;
 Physics  Fluid Dynamics
 EPrint:
 doi:10.1103/PhysRevE.83.017302