10 research outputs found
Decay laws for three-dimensional magnetohydrodynamic turbulence
Decay laws for three-dimensional magnetohydrodynamic turbulence are obtained
from high-resolution numerical simulations using up to 512^3 modes...
Scaling properties of three-dimensional magnetohydrodynamic turbulence
The scaling properties of three-dimensional magnetohydrodynamic turbulence
are obtained from direct numerical simulations of decaying turbulence using
modes. The results indicate that the turbulence does not follow the
Iroshnikov-Kraichnan phenomenology.In the case of hyperresistivity, the
structure functions exhibit a clear scaling range yielding absolute values of
the scaling exponents . The scaling exponents agree with a modified
She-Leveque model , corresponding to Kolmogorov
scaling but sheet-like geometry of the dissipative structures
Statistical anisotropy of magnetohydrodynamic turbulence
Direct numerical simulations of decaying and forced magnetohydrodynamic (MHD)
turbulence without and with mean magnetic field are analyzed by higher-order
two-point statistics. The turbulence exhibits statistical anisotropy with
respect to the direction of the local magnetic field even in the case of global
isotropy. A mean magnetic field reduces the parallel-field dynamics while in
the perpendicular direction a gradual transition towards two-dimensional MHD
turbulence is observed with inertial-range scaling of the
perpendicular energy spectrum. An intermittency model based on the Log-Poisson
approach, , is able to describe the observed
structure function scalings.Comment: 4 pages, 3 figures. To appear in Phys.Rev.
Magnetohydrodynamic turbulence
This book presents an introduction to, and modern account of, magnetohydrodynamic (MHD) turbulence, an active field both in general turbulence theory and in various areas of astrophysics. The book starts by introducing the MHD equations, certain useful approximations and the transition to turbulence. The second part of the book covers incompressible MHD turbulence, the macroscopic aspects connected with the different self-organization processes, the phenomenology of the turbulence spectra, two-point closure theory, and intermittency. The third considers two-dimensional turbulence and compress