THREE-DIMENSIONAL MODELING OF COMPRESSIBLE MAGNETOHYDRODYNAMIC TURBULENCE IN THE LOCAL INTERSTELLAR MEDIUM

We apply the large eddy simulation technique to carry out a three-dimensional numerical simulation of compressible magnetohydrodynamic turbulence in conditions relevant to the local interstellar medium. In accord with the large eddy simulation method, the large-scale part of the flow is computed directly and only small-scale structures of turbulence are modeled. The small-scale motion is eliminated from the initial system of equations of motion by filtering procedures, and its effect is taken into account by special closures referred to as the subgrid-scale models. Establishment of the weakly compressible limit with a Kolmogorov-like density fluctuation spectrum is shown in the present work. We use our computation results to study the dynamics of the turbulent plasma beta and anisotropic properties of the magnetoplasma fluctuations in the local interstellar medium.