Conservative remapping and region overlays by intersecting arbitrary polyhedra

An efficient algorithm for first-order grid intersections, by computing geometrically the intersection volume between donor and target zones, is developed for polyhedral meshes. We examine two applications of grid intersections. One application is first-order remapping, in which zone and node centered fields defined on a given mesh are transferred to a different mesh. The second application is region overlays, in which a region with homogeneous material properties is approximated by a grid of polyhedra and mapped onto an arbitrary hexahedral mesh, creating mixed zones on the boundary of the region. We demonstrate the use of this grid intersection algorithm within the framework of hydrodynamics simulations, and using a domain decomposed mesh, we study the feasibility of a parallel implementation, (C) 1999 Academic Press.