Code verification and code validation are essential activities in establishing the usefulness of numerical models. Verification means ensuring that the code correctly solves the intended model equations by comparing it with analytic solutions and benchmarking it against other codes. Validation means ensuring that the model itself captures the essential physics of the experiments.
The following links provide self-contained descriptions of a number of verification-benchmark tests relevant to the stability of edge and scrape-off-layer plasmas in tokamaks. Comparisons of 2DX results are made with both semi-analytical results (for simplified geometry cases) and with the BOUT and BOUT++ edge turbulence codes (in full divertor and X-point geometry). In one case, for a model ELM problem, four codes (2DX, ELITE, GATO and BOUT++) were all successfully benchmarked against each other.
These tests serve to (i) verify the coding of the physics models within 2DX, (ii) verify both 2DX and BOUT in cases where they have been compared, and (iii) provide solid results which other codes can employ as benchmark targets. Many of these linked documents have also been made available to the Edge Coordination Committee (ECC) for display on the V&V section of their website. A table showing the scope of tests (B – J) is given as Appendix A, below.
This page was last updated on 7/5/2011.