Hello,

I am trying to simplify a pipe flow to a 2D axisymmetric flow simulation and thought axial periodicity will do the job but I find a big different between my velocity/pressure results when comparing to 3D simulation! I can tell that the axial periodicity results are wrong. Can somebody from Solidworks flow comment about this?

No. Out of the three symmetry choices axial periodicity is a pattern that repeats linearly, like a multiple row heat exchanger, where you can find the effect of n rows or periods going through similar geometry rows of tubes. Axisymmetry is restricted to volumes of revolution that have the exact same cross-section at any angle (where the flow pattern is symmetric as well). Finally cyclic symmetry is very commonly used for things like turbine blades, where a non-constant cross section (like a blade) repeats in a pattern n times, where this time the number of cycles is automatically derived from the angle of the wedge.