Mixsim2: impeller surfaces generated at mistaken location
MixSim 2 can create surfaces around impellers automatically using the menu item "Postprocessing---Impeller-Surfaces".
Sometimes, some time after their creation, and after other actions have been performed (may include writing and re-loading files!), these surfaces don't appear in their correct locations, but are all moved to some places where no impeller is located. If more than one impeller is in the model, they are all arranged along one shaft, or along the tank's vertical central axis.
These surfaces are stored by their definition, which is always some iso-surface of a grid coordinate, clipped by another grid coordinate. These grid coordinates are cylindrical coordinates, whose definitions are understood in FLUENT as being relative to the cylindrical coordinate defintion in that particular (fluid) cell zone that is the current "Reference Zone" (can be checked in the FLUENT GUI at "Report---Reference-Values" in the bottom of the panel).
To get the impeller surfaces in the right locations again, please simply re-created them!
(It is not necessary to delete them first.)