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Phenomenology of non-Alfvenic turbulence in a uniformly expanding mediumTransport and decay of magnetohydrodynamic (MHD) turbulence in a weakly inhomogeneous uniformly expanding medium involves a fairly complex formalism, even for the case where no spectral information is required. Here we argue that the phenomenology for decay simplifies greatly if: (1) the cross helicity (Alfvenicity) is small, (2) the dynamical influence of the large scale magnetic field is negligible either because of spectral anisotropy or because the expansion speed is much greater than the corresponding Alfven speed, and (3) the ratio of kinetic energy to magnetic energy for the fluctuations is either unity or some other constant. These conditions are acceptable as an approximation to solar wind turbulence in the outer heliosphere. In these circumstances a reasonable MHD energy-containing phenomenology is essentially that of locally homogeneous Kolmogoroff turbulence in a uniformly expanding medium. Analytical solutions for this model are presented for both undriven and driven cases.
Document ID
19960021419
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
Authors
Matthaeus, W. H.
(Delaware Univ. Newark, DE United States)
Zank, G. P.
(Delaware Univ. Newark, DE United States)
Date Acquired
August 17, 2013
Publication Date
June 30, 1995
Subject Category
Solar Physics
Accession Number
96N24815
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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