Find the most similar (perfectly working) case as possible. Make a copy of it and rename it.
Number of regions fits? If not, add missing ones, or remove extra ones. Names of regions are specified in: constant/regionProperties
Each region has its independent mesh. Do I have mesh to convert? Then e.g. copy it to meshFactory/mesh-rotor/rotor.msh, see francis-periodic-hex-noSpiral tutorial. Or do I create new mesh in snappyHexMesh? Then configure meshFactory/mesh-rotor/system/snappyHexMeshDict, see kaplan-full-snappy tutorial
For every region edit meshFactory/mesh-xxxxx/convertMesh script to create/convert the new mesh.
If needed edit configure meshFactory/mesh-rotor/system/createPatchDict.renamePatches to fit default patch names (easy for default boundary conditions ).
If needed edit configure meshFactory/mesh-rotor/system/changeDictionaryDict
Watch the resulted mesh. Check the model scales are in meters.