Unstructured Mesh Technologies for Massively Parallel Simulation and Data Analysis of Magnetically Confined Plasmas

The simulation of magnetically confined plasmas requires consideration of multiple overlapping scales. Continuum models address reactor scale behaviors, while particle methods capture fine scale behavior. The complex combination of physics and reactor geometry results in simulations involving massive calculations and data sets, which can only be executed on parallel computers. Thus, there is a critical need for effective methods that can execute coupled simulations with fully parallel representations, and computations, at both the continuum and particle level with specific consideration of the ability to perform validation with experimentally measured data. The goal of this project is to develop structures and tools for multiscale plasma simulations that provide a parallel mesh and particle infrastructure, geometry and meshing methods that can support fully detailed reactor geometries, methods for scalable coupled mesh and particle operations, and a user interface for specification of the fusion plasma simulation workflows. Phases II efforts have provided: A parallel mesh/particle infrastructure for effective particle-in-cell simulations. Methods to couple simulation data to uncertainty quantification and optimization. Geometry construction and meshing tools for tokamak and stellarator systems. A graphical user interface for fusion simulations. The tools developed in the project have been integrated into multiple tools being used by several fusion research groups. The Phase IIB project will address new challenges related to the definition, coupling, and meshing of detailed geometries being considered by fusion researchers. Developments will focus on the automatic creation of appropriate analysis models from input data consisting of complex design geometries and physics geometries from other simulations. New meshing and mesh adaptivity capabilities will be developed which are appropriate for simulations of both tokamak and stellarator systems. All of the developments will be actively coordinated with ongoing research into the simulation of fusion systems.Commercial Applications and Other Benefits The combined mesh plus particle methods to be developed will provide a set components that can support the new generations of multiscale/multiphysics simulations needed in the modeling of fusion and fission reactors, and for application in nuclear medicine. The analysis geometry construction/clean-up and meshing methods being developed in this project are needed for the effective application of the high fidelity simulations needed to advance a wide variety of applications. Recent examples include the modeling of small-scale active flow devices in large-scale aircraft applications, modeling of additive manufacturing processes and medical device simulations.