SnappyHexMesh

In order to define the patches with snappyHexMesh you need to use different files (in STL format, for compatability reasons, wrting in STL-ASCII format might be beneficial) that can assemble in a watertight shell geometry. Use the utility surfaceCheck to proof that your STL is watertight.

The files are suppoed to be stored in “constant/triSurface” rigorously in this format <file>.stl and plus a description on “sytem/surfaceFeatureDict” substituting and adding the entries and modifying the featured angles (170°(advised) - 180°: to include all the angles between two neighboured cells, lowering this value it wouldn’t be consider these cells and it will be applied a merged cell).

How to start a case in single and parallel

After the execution of:

surfaceFeatureExtract

in “constant/triSurface” the same folder should appear <file>.eMesh and a new directory will be generated as “constant/extendedFeatureEdgeMesh”

If you want to extract very thin layer, use the utility

extrudeMesh

dependent on the dictionary system/extrudeMeshDict to extrude some layers externally to the geometry, however, make sure that those created are very thin.

The following commands will start the meshing process:

Meshing multiples bodies

If you want to mesh different entities with separate mesh, you might run twice snappyHexMesh with different value of Location in mesh and then use the tool mergeMesh. Otherwise you can use the dictionary before running the mesh. To permit the recognition of different closed STL files the sub-dictionary “snappyHexMesh.castellatedMeshControls.locationInMesh” must be modified in “snappyHexMesh.castellatedMeshControls.locationsInMesh” and follow a similar resolution:

    …
   locationsInMesh
      (
        ((0.010276 0.058958 0.000248) zone1)
  	    ((0.011472 0.10046  0.000256) zone2)
       );
   …

In this scenario, it is possible to introduce to bodies as a single mesh without recurring to use the utility mergeMeshes. The bodies will be distinguished from a different cellZones allocations.