Streamline integration as a method for structured grid generation in X-point geometry
| Autor: | Matthias Wiesenberger, Alexander Kendl, Markus Held, Lukas Einkemmer |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
Physics and Astronomy (miscellaneous)
Computer science FOS: Physical sciences Topology 01 natural sciences 010305 fluids & plasmas Saddle point 0103 physical sciences Convergence (routing) Volume element 010306 general physics Streamline integration Computer Science::Distributed Parallel and Cluster Computing Monitor metric Numerical Analysis Structured grid Applied Mathematics Computational Physics (physics.comp-ph) Grid X-point Computer Science Applications Computational Mathematics Rate of convergence Mesh generation Modeling and Simulation Metric (mathematics) Laplace operator Physics - Computational Physics |
| Zdroj: | Wiesenberger, M, Held, M, Einkemmer, L & Kendl, A 2018, ' Streamline integration as a method for structured grid generation in X-point geometry ', Journal of Computational Physics, vol. 373, pp. 370-384 . https://doi.org/10.1016/j.jcp.2018.07.007 Journal of Computational Physics |
| Popis: | We investigate structured grids aligned to the contours of a two-dimensional flux-function with an X-point (saddle point). Our theoretical analysis finds that orthogonal grids exist if and only if the Laplacian of the flux-function vanishes at the X-point. In general, this condition is sufficient for the existence of a structured aligned grid with an X-point. With the help of streamline integration we then propose a numerical grid construction algorithm. In a suitably chosen monitor metric the Laplacian of the flux-function vanishes at the X-point such that a grid construction is possible. We study the convergence of the solution to elliptic equations on the proposed grid. The diverging volume element and cell sizes at the X-point reduce the convergence rate. As a consequence, the proposed grid should be used with grid refinement around the X-point in practical applications. We show that grid refinement in the cells neighbouring the X-point restores the expected convergence rate. |
| Databáze: | OpenAIRE |
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