Meshing

Importing Meshes

PyFR is capable of importing meshes in the Gmsh .msh format; specifically versions 2.2 and 4.1 of the ASCII format with the latter being recommended. Although these files can include partitioning information this is ignored by PyFR. In order to be imported by PyFR the following guidelines must be followed:

• Elements must be assigned a physical name of “fluid”.

• Boundaries can be assigned any physical name. However, the node numbers of faces on the boundary must match perfectly with the faces of the corresponding elements in the fluid region. Any discrepancies here will result in KeyError exceptions being raised on import. Such errors usually arise when Gmsh is asked to make a volume mesh whose characteristic size near a boundary is greater than the spacing of points used to define the boundary itself. The result is a boundary mesh which is inconsistent with the surface of the fluid mesh.

• Periodic boundary conditions can be defined by assigning one of the boundaries a physical name of “periodic-name-l” and the other a physical name of “periodic-name-r” where name is an arbitrary identifier. Note that only translational peridocity is currently supported.

• Curved elements are supported up to quartic order. Such elements must be complete Lagrange elements as opposed to incomplete serendipity elements.