For creating new mesh with snappyHexMesh it is recommended to create new OpenFOAM test case just with system and constant directory.
The input .STL files are located in constant/triSurface and can be directly viewed in paraview.
# paraview
Five .STL files are presented, namely align-rot-draft.stl, align-rot-guide.stl, blade-rot.stl, hub-rot.stl, shroud-rot.stl.
Interface between rotor and spiral (stator) part is defined by align-rot-guide.stl file and interface between rotor and drafttube (stator) part is given by align-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.