Fractality feature in incompressible three-dimensional magnetohydrodynamic turbulence
| Autor: | Mahdi Momeni, M Moslehi-Fard |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Length scale
Physics Field (physics) Turbulence QC1-999 Direct numerical simulation General Physics and Astronomy self-similar Probability density function magnetohydrodynamic turbulence Magnetohydrodynamic turbulence law.invention Physics::Fluid Dynamics 47.65.-d 47.27.e 47.27.ek fractal law Intermittency 47.53.+n Magnetohydrodynamic drive Statistical physics Magnetohydrodynamics |
| Zdroj: | Open Physics, Vol 6, Iss 3, Pp 759-764 (2008) |
| ISSN: | 1208-6045 0008-4204 |
| DOI: | 10.1139/p08-030 |
| Popis: | High-resolution direct numerical simulation data for three-dimensional magnetohydrodynamic (MHD) turbulence based on the 10243-modes in a periodic box are used to study the statistical properties of turbulence. In this paper, the presence of intermittency in MHD turbulence is investigated through the analysis of the Probability Distribution Function (PDF) for Elsässer fields and total energy fluctuations. The energy PDFs exhibit similarity over all scales of the turbulent system since they show no substantial qualitative change in shape as the scale of the fluctuations varies. This is in sharp and surprising contrast to the well-known behavior of PDFs of turbulent field fluctuations of, for example, velocity, and magnetic and Elsässer fields. The PDFs have exponential tails and satisfy the function P(| δX |) ~ exp(–A | δX | μ). Numerically, we extract the exponent μ and find that it is constant for monofractal behavior as the scale of length varies. The compensated structure functions exhibit self-similarity for the respective fluctuations, and it is a reliable way in turbulence. PACS Nos.: 52.30.–q , 52.30.Cv , 52.35.Ra , 52.65.–y |
| Databáze: | OpenAIRE |
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