Generating Massive Unstructured Meshes for OpenFOAM

OpenFOAM is an open source computational uid dynamics (CFD) package with a large user base from many areas of
engineering and science. This whitepaper documents an enablement tool called PMSH that was developed to generate
multi-billion element unstructured tetrahedral meshes for OpenFOAM. PMSH is developed as a wrapper code around
the popular open source sequential Netgen mesh generator. Parallelization of the mesh generation process is carried out
in ve main stages: (i) generation of a coarse volume mesh (ii) partitioning of the coarse mesh to get sub-meshes, each
of which is processed by a processor (iii) extraction and re nement of coarse surface sub-meshes to produce ne surface
sub-meshes (iv) re-meshing of each ne surface sub-mesh to get the nal ne volume mesh (v) matching of partition
boundary vertices followed by global vertex numbering. An integer based barycentric coordinate method is developed
for matching distributed partition boundary vertices. This method does not have precision related problems of
oating
point coordinate based vertex matching. Test results obtained on an SGI Altix ICE X system with 8192 cores and 14 TB
of total memory con rm that our approach does indeed enable us to generate multi-billion element meshes in a scalable
way. PMSH tool is available at https://code.google.com/p/pmsh/.