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Astron. Astrophys. 343, 251-260 (1999)
Numerical simulations of stellar winds: polytropic models
R. Keppens and
J.P. Goedbloed
FOM-Institute for Plasma-Physics Rijnhuizen, P.O.
Box 1207, 3430 BE Nieuwegein, The Netherlands (e-mail:
keppens@rijnh.nl; jpg@rijnh.nl)
Received 8 August 1998 / Accepted 2 December 1998
Abstract
We discuss steady-state transonic outflows obtained by direct numerical solution of the hydrodynamic and magnetohydrodynamic equations. We make use of the Versatile Advection Code, a software package for solving systems of (hyperbolic) partial differential equations. We proceed stepwise from a spherically symmetric, isothermal, unmagnetized, non-rotating Parker wind to arrive at axisymmetric, polytropic, magnetized, rotating models. These represent 2D generalisations of the analytical 1D Weber-Davis wind solution, which we obtain in the process. Axisymmetric wind solutions containing both a `wind' and a `dead' zone are presented.
Since we are solving for steady-state solutions, we efficiently exploit fully implicit time stepping. The method allows us to model thermally and/or magneto-centrifugally driven stellar outflows. We particularly emphasize the boundary conditions imposed at the stellar surface. For these axisymmetric, steady-state solutions, we can use the knowledge of the flux functions to verify the physical correctness of the numerical solutions.
Key words: Sun: solar
wind 
methods:
numerical
Magnetohydrodynamics (MHD)
Send offprint requests to: R. Keppens
This article contains no SIMBAD objects.
Contents
- 1. Introduction
- 2. Equations
- 3. Versatile advection code
- 4. 1D polytropic winds
- 4.1. Parker winds
- 4.2. Weber-Davis winds
- 5. Axisymmetric 2D polytropic HD winds
- 6. Axisymmetric 2D polytropic MHD winds
- 7. Conclusions and outlook
- Acknowledgements
- References
© European Southern Observatory (ESO) 1999
Online publication: March 1, 1999
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