The geometry dictionary describes all input geometry required by snappyHexMesh:

  • the surface to conform to, e.g. triangulated surfaces and analytical shapes
  • regions for volumetric or surface refinement
  • setting constraints on internal faces to generate face sets or face zones for regions

The geometry section can describe triangulated surfaces or searchable objects. A simple definition may take the form:

    sphere.stl  // name of the geometrical entity
        type            triSurfaceMesh;

    myBox       // name of the geometrical entity
        type            searchableBox;
        min             (1.5 1 -0.5);
        max             (3.5 2 0.5);

Triangulated surfaces

Triangulated surfaces must be located in the $FOAM_CASE/constant/triSurface directory. The following formats are supported:

  • stl - Stereolithography ASCII
  • stlb - Stereolithography binary
  • obj - Wavefront object
  • vtk - Legacy Visualisation Toolkit (VTK)
  • ftr - OpenFOAM triangulated format
  • ac, smesh, tri and dx

Some formats support multiple regions, e.g. β€˜SOLID’ in the stl format. Each surface and region in a surface becomes a separate patch in the final mesh.

Searchable objects

These objects define analytical shapes, and are treated similarly to triangulated surfaces, e.g. to define the geometry to mesh or refinement regions.