MixSim 2.1.10: custom impeller missing free floating face from ACIS file
In a Custom impeller (defined by an ACIS file), the impeller blades are not attached to the hub, i.e. they are "free floating in space".
A blade gets lost from the geometry when a coil is introduced (exactly when Gambit does the subtract operation for the coil).
This can probably occur for any kind of free-floating face, i.e. any face in a Custom impeller or Custom baffle ACIS file that does not intersect with any volume.
Workaround: Attach the blades to the hub, i.e. increase the hub dimensions so that there is intersection between the hub and the blades. Make sure the hub dimensions are chosen such that no sharp angles, short edges, or small gaps are produced.
More general speaking: free-floating faces in Custom impeller or Custom baffle geometries may get lost -- consider attaching them to some volume.