Astronomy and Astrophysics – Astronomy
Scientific paper
Jan 2012
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012apj...745...35z&link_type=abstract
The Astrophysical Journal, Volume 745, Issue 1, article id. 35 (2012).
Astronomy and Astrophysics
Astronomy
Magnetohydrodynamics: Mhd, Sun: Heliosphere, Turbulence
Scientific paper
Numerous problems in space physics and astrophysics require a detailed understanding of the transport and dissipation of low-frequency turbulence in an expanding magnetized flow. We employ a scale-separated decomposition of the incompressible MHD equations (based on an Elssässer description) and develop a moment hierarchy to describe the transport of the total energy density in fluctuations, the cross-helicity, the energy difference, and correlation lengths corresponding to forward- and backward-propagating modes and to the energy difference. The dissipation terms for the various transport equations are derived. One-point closure schemes are utilized. The technical elements of this work that distinguish it from previous studies are (1) the inclusion of the large-scale background inhomogeneous Alfvénic velocity V A at a level of detail greater than before, (2) the introduction of a tractable slow timescale closure to eliminate high-frequency interference terms that is likely to prove a useful approximation for practical problems related to the transport of turbulence in an inhomogeneous flow such as the solar wind or solar corona, and finally, (3) we develop a simplified phenomenology for the energy difference or equivalently residual energy that may be useful for practical applications. This yields a coupled system of six equations that describes the transport of turbulence in inhomogeneous sub-Alfvénic and super-Alfvénic flows. The turbulence transport equations are quasi-linear in their spatial evolution operators and nonlinear in the dissipation terms, making the model equations relatively tractable to analysis.
Dosch Alexander
Florinski Vladimir
Hunana P.
Matthaeus William H.
Webb Gary M.
No associations
LandOfFree
The Transport of Low-frequency Turbulence in Astrophysical Flows. I. Governing Equations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Transport of Low-frequency Turbulence in Astrophysical Flows. I. Governing Equations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Transport of Low-frequency Turbulence in Astrophysical Flows. I. Governing Equations will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-751422