Strong magnetohydrodynamic turbulence with cross helicity
- Department of Physics, University of Wisconsin at Madison, 1150 University Ave., Madison, Wisconsin 53706 (United States)
Magnetohydrodynamics (MHD) provides the simplest description of magnetic plasma turbulence in a variety of astrophysical and laboratory systems. MHD turbulence with nonzero cross helicity is often called imbalanced, as it implies that the energies of Alfven fluctuations propagating parallel and antiparallel the background field are not equal. Recent analytical and numerical studies have revealed that at every scale, MHD turbulence consists of regions of positive and negative cross helicity, indicating that such turbulence is inherently locally imbalanced. In this paper, results from high resolution numerical simulations of steady-state incompressible MHD turbulence, with and without cross helicity are presented. It is argued that the inertial range scaling of the energy spectra (E{sup +}-) of fluctuations moving in opposite directions is independent of the amount of cross helicity. When cross helicity is nonzero, E{sup +} and E{sup -} maintain the same scaling, but have differing amplitudes depending on the amount of cross helicity.
- OSTI ID:
- 21371185
- Journal Information:
- Physics of Plasmas, Vol. 17, Issue 5; Other Information: DOI: 10.1063/1.3396370; (c) 2010 American Institute of Physics; ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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