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P: Plasmaphysik

P XI: HV XI

P XI.1: Hauptvortrag

Donnerstag, 20. März 2003, 11:00–11:30, FO1

Numerical Plasma Dynamics: simulating magneto-fluids. — •Rony Keppens — FOM-Institute for Plasma Physics Rijnhuizen, P.O.Box 1207, 3430 BE Nieuwegein, The Netherlands

Highly ionized plasma dynamics is encountered in laboratory plasma devices as well as in virtually all astrophysical phenomena. In many cases, magnetic fields play a crucial role. A suitable model for the macroscopic behavior of such magneto-fluids is provided by the equations of MagnetoHydroDynamics (MHD). These equations are very well suited to perform scale-encompassing numerical simulations of multi-dimensional non-linear magnetized plasma flows. For that purpose, we continue the development and exploitation of the Versatile Advection Code [www.phys.uu.nl/∼toth], along with its recent extension which employs dynamically controlled grid adaptation.

I will present simulations of 3D non-linearly interacting fundamental plasma instabilities, relevant when dealing with cospatial shear flow and twisted magnetic fields. Such magnetized jet flows can be susceptible to a wide variety of hydro- (e.g. Kelvin-Helmholtz) or magnetohydrodynamic (e.g. current driven kink) instabilities. Recent MHD computations of 3D jet flows have revealed how such mutually interacting instabilities can in fact aid in maintaining jet coherency. Another breakthrough from computational magneto-fluid modeling in a more astrophysical context is the demonstration of continuous, collimated, transmagnetosonic jet launching from magnetized accretion disks. Summarizing, MHD simulations are rapidly gaining realism and significantly advance our understanding of non-linear laboratory and astrophysical magneto-fluid dynamics.