For creating new mesh with snappyHexMesh it is recommended to create new OpenFOAM test case just with system and constant directory. Go to your user directory and create directories for rotor region mesh. It is recommended to copy a similar tutorial case and modify just the different parts of the case.

The input .STL files are located in constant/triSurface and can be directly viewed in paraview.

# paraview

Seven .STL files are presented, namely blade-rot.stl, hub-rot-tip.stl, hub-rot-wall.stl, hub-rot-wheel.stl, interface-rot-draft.stl, interface-rot-guide.stl, shroud-rot.stl.

Interface between rotor and spiral (stator) part is defined by interface-rot-guide.stl file and interface between rotor and drafttube (stator) part is given by interface-rot-draft.stl.

The initial idea is to create following mesh boundaries: shroud, hub, blade and two interfaces. Their number and names may change during the creation process.