In general, this methodology allows working with any number of regions. This computational model consists of two parts (regions). Each region has its own mesh and its own settings. Regions are connected via interfaces. In this tutorial we consider following two regions:

• rotor is rotational part of the model (either full wheel, or periodic part with single blade), fluid is flowing over rotating wheel. Inlet tube can be included to rotor region, although it is recommended the MRF zone keep just in the wheel (as small as possible).
• stator is static part of the model, typically a spiral with different mesh from other regions