Strategies in edge plasma simulation using adaptive dynamic nodalisation techniques

Edge plasma steady-state and transient problems can be treated requiring accurate discretization techniques, like the propagation of sharp or abrupt changes of properties. The 2D-Finite Element mesh generator developed produces adaptive unstructured grids from flux surface characteristics. Finite Volume (FV) use such structured grids, and utilize recently adaptive unstructured grids for both Finite Element (FE) and FV methods as well. The initial mesh's quadrilateral elements are generated automatically and interactive generator extensions allow changes to edges following approximately equipotential lines and lines of slope. Element-connectivity-requirements of various solvers and propagation effects of refinement and coarsening are controlled. Methods of realignment are introduced to preserve refinement of front areas and alignment to the magnetic field. For common mesh handling features of FE/FV packages, variants have been added to the basic generation tool. Other enhancements include transition elements, triangular grid options which can be modified by the basic adaptation/realignment techniques, complex shapes can be treated this way. (author)