Portable implementation of implicit methods for the UEDGE and BOUT codes on parallel computers
A description is given of the parallelization algorithms and results for two codes used ex- tensively to model edge-plasmas in magnetic fusion energy devices. The codes are UEDGE, which calculates two-dimensional plasma and neutral gas profiles, and BOUT, which cal- culates three-dimensional plasma turbulence using experimental or UEDGE profiles. Both codes describe the plasma behavior using fluid equations. A domain decomposition model is used for parallelization by dividing the global spatial simulation region into a set of domains. This approach allows the used of two recently developed LLNL Newton-Krylov numerical solvers, PVODE and KINSOL. Results show an order of magnitude speed up in execution time for the plasma equations with UEDGE. A problem which is identified for UEDGE is the solution of the fluid gas equations on a highly anisotropic mesh. The speed up of BOUT is closer to two orders of magnitude, especially if one includes the initial improvement from switching to the fully implicit Newton-Krylov solver. The turbulent transport coefficients obtained from BOUT guide the use of anomalous transport models within UEDGE, with the eventual goal of a self-consistent coupling.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE Office of Defense Programs (DP)
- DOE Contract Number:
- W-7405-Eng-48
- OSTI ID:
- 8018
- Report Number(s):
- UCRL-ID-133226; AT5020100; ON: DE00008018
- Country of Publication:
- United States
- Language:
- English
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