Multiple-Scale Analysis of the Strong Compressibility Effects on Transport in Magnetohydrodynamic Turbulence

Abstract

Fully compressible magnetohydrodynamic (MHD) turbulence is investigated with the aid of the multiple-scale direct-interaction approximation, a combination of the direct-interaction approximation (DIA) with the multiple-scale analysis. The turbulent correlations in the mean-field equations are expressed in terms of the propagators of the MHD turbulence, which include the electromotive force, the Reynolds and turbulent Maxwell stresses, the turbulent mass and internal energy fluxes, etc. The strong compressibility effects are incorporated through the density variance for some transport coefficients. A system of turbulence model is also constructed on the basis of the analytical expressions of the turbulent correlations.