Ansys Polystat does not support mixing tasks on CutCell meshes.

Ansys Polystat does not support mixing tasks on meshes with subdivided elements. See Appendix C: Adaptive Meshing and Mixing Task for a method to circumvent this limitation.

Ansys Polystat does not support mixing tasks if the flow field is meshed using the sliding mesh technique. See Appendix D: Sliding Mesh Technique and Mixing Task for a method to circumvent this limitation.

When using the Mesh Superposition Technique (MST) with moving parts (with or without slippage along the moving parts), the trajectories and kinematics of the deformation may be affected when material points (massless particles) are close to the surface of the moving parts.

When using MST with moving parts, it may happen that some of the material points get overlapped by a moving part. This is due to the accumulation of small errors along the trajectory of the material points. There are two ways (which can be combined) to limit this problem: decreasing the time step between two successive flows and refining the mesh of the flow domain.

Ansys Polystat does not support mixing tasks if the mesh of the flow domain changes with time (changes in coordinate position of the mesh vertices and/or number and shape of mesh elements). This does not include the use of the Mesh Superposition Technique with moving parts on a transient flow field, because the underlying mesh remains constant.

Ansys Polystat does not support mixing tasks on flow fields defined by non-conformal boundaries.

In some cases, material points (massless particles) may stop on an impermeable boundary (wall, free surface, plane of symmetry) due to stagnation of the flow field in close proximity to these boundaries. This can have a dramatic effect on the flow statistics, particularly if you are analyzing an open flow field (with entry and exit of fluid). When slicing from entry to exit you should confirm that the number of samples in each slice remains constant. If the concentration of samples decreases by more than 10–15%, it may be necessary to refine the mesh.

Ansys Polystat does not support mixing tasks on compressible fluids.