Mesh file contents#

The mesh generators produce one or more mesh files containing the following entities:

  • One or more principal meshes, specified by namelist (mesh names).

  • (Optional) Derived meshes from a specified principal mesh, e.g. Rim mesh, Eave mesh.

  • (Optional) InterMesh maps between two specified principal meshes.

  • (Local mesh) Information on partition (halos etc.) and non-partitioned global mesh.

Principal meshes#

These meshes are explicitly defined from the mesh configuration namelists

Derived meshes#

These mesh types may require additional input, though crucially, are derived from one of the specified principal meshes. They cannot be separately generated from the parent principal mesh. Derived meshes are implicitly linked to their parent mesh via a one-way InterMesh map (Derived -> Principal InterMesh map).

InterMesh maps#

InterMesh maps provide a means of identifying co-located (or partially co-located) cells between two mesh topologies. InterMesh maps are attached to the source mesh, and record which cells on the target mesh are co-located to a given cell on the source mesh. Explicit InterMesh maps are requested via mesh configuration namelists with the following restrictions:

  • Requested InterMesh maps are only available between two specified principal meshes during a mesh generation event.

  • The resolutions of the principal mesh pairing are such that one mesh is a sub-division of the other.

For explicitly requested InterMesh maps, the generator will output an InterMesh map for each direction between the meshes, i.e. source -> target, target -> source. The InterMesh map will always be attached to the source `relative` to the mapping.

Local meshes#

When partitioning global meshes for a specific domain decomposition, additional information is provided in order to populate the applications local_mesh_type objects. Partitioning results in multiple output files, one for each partition. Each file contains topologies for the principal meshes, although a local mesh only contains a subset of the cells from the global mesh. The subset of cells encompass the partition itself plus a halo region.

Additional information relating to the partition halos and the non-partitioned global mesh is output to file when the generators are requested to partition the principal meshes.