Computational meshes are generated for each region individually. With this methodology all the meshes are created using snappyHexMesh OpenFOAM application. The input for snappyHexMesh is the surface model as a set of OBJ files. It is recommended to create a temporary directory for each of the three regions just for creating the mesh, later the meshes will be merged and copied to the case directory. We will use the directories mesh-inflow, mesh-wheel and mesh-volute.