5B.1 Parallel Mesh Adaptation for Highly Evolving Geometries with Application to Solid Propellant Rockets

We describe our parallel 3-D surface and volume mesh modification strategy for large-scale simulation of physical systems with dynamically changing domain boundaries. Key components include an accurate, robust, and efficient surface propagation scheme, frequent mesh smoothing without topology changes, infrequent remeshing at regular intervals or when triggered by declining mesh quality, a novel hybrid geometric partitioner, accurate and conservative solution transfer to the new mesh, and a high degree of automation. We apply these techniques to simulations of internal gas flows in firing solid propellant rocket motors, as various geometrical features in the initially complex propellant configuration change dramatically due to burn-back. Smoothing and remeshing ensure that mesh quality remains high throughout these simulations without dominating the run time.