Statistical properties of two-dimensional magnetohydrodynamic turbulence

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Physics of Fluids B; (USA)

DOI:https://doi.org/10.1063/1.859369· OSTI ID:6144455

Biskamp, D; Welter, H; Walter, M ^[1]

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1. Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, 8046 Garching bei Muenchen, West Germany (DE)

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 {beta} model of intermittent turbulence is adapted to the MHD case. Comparison of simulation results for energy spectra with the {beta}-model predictions shows intermittency corrections to be small, {delta}{lt}0.2, while fourth-order correlation functions exhibit a stronger effect {delta}{approx equal}0.35, consistent with the numerically observed Reynolds-number dependence of the flatness factor {ital F}{proportional to}{ital R}{sup 1/2}{sub {lambda}}. An argument is given that this scaling valid for {ital R}{sub {lambda}}{approximately}10{sup 2} is, however, not characteristic of the asymptotic regime {ital R}{sub {lambda}}{r arrow}{infinity}, where a constant value of {ital F} is to be expected. The probability distributions of the field difference {delta}{bold v}({ital x},{ital t}), {delta}{bold B}({ital x},{ital t}) are Gaussian for large separation {ital x} or {ital t}, approaching an approximately exponential distribution for {ital x}, {ital t}{r arrow}0. This behavior can be understood by a simple probabilistic argument. The probability distribution of the local energy dissipation rate {epsilon} is roughly consistent with a log-normal distribution at larger {epsilon} but shows a different behavior at small {epsilon}.

• OSTI ID: 6144455
• Journal Information: Physics of Fluids B; (USA), Journal Name: Physics of Fluids B; (USA) Vol. 2:12; ISSN 0899-8221; ISSN PFBPE
• Country of Publication: United States
• Language: English

Related Subjects

640430* -- Fluid Physics-- Magnetohydrodynamics
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
FLUID MECHANICS
FUNCTIONS
GAUSS FUNCTION
HYDRODYNAMICS
MAGNETOHYDRODYNAMICS
MECHANICS
NUMERICAL SOLUTION
PROBABILITY
SIMULATION
TURBULENCE
TWO-DIMENSIONAL CALCULATIONS