cfMesh

CfMesh is a mesher which is integrate in OpenFOAM® such as SnappyHexMesh and it is possible to find the tutorial relatives to it in:

/opt/OpenFOAM/OpenFOAM-v2206/modules/cfmesh/tutorials

The modalities to create a mesh pass always through the creation of a .stl bodies as boundaries, i.e. create all different .stl file as surface (ASCII and divided per patch that you intend to apply a boundary condition)

cat body_1.stl body_2.stl body_N.stl >> combined.stl

To permit at the program to select different patches of the geometry, remember to check inside the combined file and ensure there is a space between the joint of the different STL files. To create the .fms file needed to run the cfMesh utilities (specific for OpenFoam®) run the following commands.

surfaceFeatureEdges –angle 15 combined.stl combined.fms

The flag angle permit to capture correctly sharp corner of the geometry, the lower is set the more it will be precise and computationally expensive, I found 15 being a good compromise, the default is 45. Secondly, to set the boundary condition in the easiest way, open the .fms file (the OpenFOAM® format) to change the type of boundaries (wall, patch, empty) in the first rows. Then the following modifications acts on the dictionary system/meshDict. Then to run the cited dictionary type the command:

cartesianMesh

For command to run require that the directory system/meshDict contain only the voice:

surfaceFile "…";

maxCellSize "…";

If you are not satisfied with the result, try to run these utilities to improve the results:

improveMeshQuality