ISSN:
1089-7666
Source:
AIP Digital Archive
Topics:
Physics
Notes:
The statistical properties of two-dimensional (2-D) magnetohydrodynamic (MHD) turbulence are studied by means of high-resolution numerical simulations. As a theoretical point of reference, the β model of intermittent turbulence is adapted to the MHD case. Comparison of simulation results for energy spectra with the β-model predictions shows intermittency corrections to be small, δ〈0.2, while fourth-order correlation functions exhibit a stronger effect δ(approximately-equal-to)0.35, consistent with the numerically observed Reynolds-number dependence of the flatness factor F∝R1/2λ. An argument is given that this scaling valid for Rλ∼102 is, however, not characteristic of the asymptotic regime Rλ→∞, where a constant value of F is to be expected. The probability distributions of the field difference δv(x,t), δB(x,t) are Gaussian for large separation x or t, approaching an approximately exponential distribution for x, t→0. This behavior can be understood by a simple probabilistic argument. The probability distribution of the local energy dissipation rate ε is roughly consistent with a log-normal distribution at larger ε but shows a different behavior at small ε.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.859369
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