The Parallelization of an Advancing-front, All- quadrilateral Meshing Algorithm for Adaptive analysis1

The ability to perform effective adaptive analysis has become a critical issue in the area of physical simulation. Of the multiple technologies required to realize a parallel adaptive analysis capability, automatic mesh generation is an enabling technology, filling a critical need in the appropriate discretization of a problem domain. The paving [1] algorithm’s unique ability to generate a function-following quadrilateral grid is a substantial advantage in Sandia’s pursuit of a modified h-method adaptive capability. This characteristic combined with a strong transitioning ability allow the paving algorithm to place elements where an error function indicates more mesh resolution is needed. Other desirable characteristics of this algorithm include its boundary sensitivity and orientation insensitivity (elements near the boundary are of the highest quality and the spatial orientation of the geometry has no effect on the resulting mesh). Although the original paving algorithm is highly serial, a two stage approach has been designed to parallelize the algorithm but also retain the nice qualities of the serial algorithm. Our approach also allows the subdomain decomposition used by the meshing code to be shared with the finite element physics code, eliminating the need for data transfer across the processors between the analysis and remeshing steps. In addition, the meshed subdomains are adjusted with a dynamic load balancer to improve the original decomposition and maintain load efficiency each time the mesh has been regenerated. 1. This work was performed at Sandia National Laboratories, which is operated for the U.S. Department of Energy under Contract No. DE-AC04-94AL85000.