タイトル | Modeling the decay of energy containing eddies: A source of solar wind heating |
著者(英) | Oughton, S.; Pontius, D. H.; Gray, P. C.; Matthaeus, W. H.; Hossain, M. |
著者所属(英) | Delaware Univ. |
発行日 | 1995-06-30 |
言語 | eng |
内容記述 | To understand the solar wind heating and acceleration mechanisms one needs to understand the decay of energy containing eddies. With this goal in mind, attempts have been made to extend the fluid dynamic phenomenology of large scale quasi-equilibrium to the case of magnetohydrodynamics. Matthaeus et al. have proposed a model for the inhomogeneous transport and decay of five mean variables, namely, two mean square Elsasser variables z(exp 2) (sub +/-) their correlation lengths, and the difference between the kinetic and magnetic energies. We test the validity of this model in the simplified case of homogeneous turbulence simulated in a periodic box. We propose a class of models and show that they may fit the simulation satisfactorily. Analytic solutions of this class of model reveal their inherent properties and demonstrate the difficulties associated with finite cross helicity. It is noted that adjustments are required to make the simplest models, which are based upon isotropic turbulence, scale properly with respect to the strength of the mean magnetic field. This can be interpreted as due to anisotropic turbulence, which can be modelled by simple parameterization in the phenomenology. |
NASA分類 | Solar Physics |
レポートNO | 96N24820 |
権利 | No Copyright |
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