Bochum 2015 – wissenschaftliches Programm
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P: Fachverband Plasmaphysik
P 22: Helmholtz Graduate School for Plasma Physics II
P 22.4: Fachvortrag
Mittwoch, 4. März 2015, 17:45–18:10, HZO 50
Modelling the Vlasov equation on complex geometries using the Semi-Lagrangian scheme — •Laura Mendoza1, Virginie Grandgirard2, Ahmed Ratnani1, and Eric Sonnendrücker1 — 1Max-Planck-Institut für Plasmaphysik, 85748, Garching, Germany — 2CEA-Cadarache, IRFM, 13108, Saint-Paul-lez-Durance, France
The GYSELA code is a non-linear 5D global gyrokinetic code which performs flux-driven simulations to solve the gyrokinetic Vlasov equation coupled with the Poisson equation. Its 3D spatial representation is limited to circular toroidal geometry (r, θ, ϕ). Currently the poloidal plane, a circular cross-section, is discretized with a polar mesh. Due to the singularity of this mapping on its origin, the geometry is discontinuous (with a hole in the center).
Thus our aim is to generalise GYSELA’s geometry definition using IGA so that any geometry, however complex, can be simulated by mapping one or multiple patches. We decided to study two different approaches to solve this problem: on the one hand, Non-Uniform Rational B-Splines (NURBS), which provide an exact representation of complex shapes; on the other hand, using a regular equilateral triangle mesh of hexagonal form on which we will work with Box-Splines.
The GYSELA code is one of many examples of why we need Semi-Lagrangian codes adapted to complex geometries. Other examples from plasma physics (and further goals) are the X-point, the scrape-off layer or edge plasma, 3D representation of a Tokamak and Stellarator, etc.