CFX doesn’t have a 2d solver so assumes the domain is one cell thick. Fluent does have a 2d solver so then works on faces rather than volumes.
Flattening to true 2d in Fluent may break the rotational periodic option that you’re trying to mimic. You may need to create a curved 3d model but set inner & outer annular faces as symmetry and have only one cell in the radial coordinate. You can then follow the turbo examples for the rotor-stator configuration. Note, check the interface settings to ensure you’re retaining the data on both sides of the interface: you don’t want any averaging!
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