Reply To: Floating point on ansys Fluent with periodic boundaries.

[Rob]

If the facets don't exactly align you can't use the "normal" periodic options. Have a look in the non conformal interface options: you can use those to create periodics. Chances are your mesh nearly lines up but is out of tolerance somewhere.
However, if the flow is aligned with the wing just set a symmetry plane or use 2d. If it's not aligned you need to refine the mesh in the z-direction as 3 tet cells isn't enough.