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Kinetic helicity and MHD turbulence

Abstract
The issue of dynamical anisotropy in helical three-dimensional magnetohydrodynamic turbulence with a mean magnetic field Bâ‚€ is investigated. Using high-resolution direct numerical simulations, we follow the evolution of various isotropic initial states characterized by their different values of the kinetic helicity. The cross helicity and magnetic helicity of the initial conditions are also varied. In agreement with earlier work, we find that such initial states become anisotropic in of order an eddy-turnover time, with correlation lengths parallel to Bâ‚€ remaining largely unchanged while finer scales are excited in the perpendicular directions. Moreover, it is found that the development of both the anisotropy and the energy are essentially independent of the initial level of kinetic helicity. The physics associated with this latter feature is discussed.
Type
Journal Article
Type of thesis
Series
Citation
Oughton, S., & Prandi, R. (2000). Kinetic helicity and MHD turbulence. Journal of Plasma Phycis, 64(2), 179-193.
Date
2000
Publisher
Cambridge University Press
Degree
Supervisors
Rights
© 2000 Cambridge University Press