[flotus1]

Lets say I wanted to use a mesh with a topology like this for LES validations.
block_structure.jpg

What would be the best way to handle the interfaces between the mesh regions with different resolutions?

1. Setting up non-conformal interfaces in Fluent (I know that this kind of interface does not preserve turbulent fluctuations and alters the instantaneous flow field even if the flow scales are well-resolved on both sides of the interface, so I only add this here for completeness)
2. Solving with hanging nodes. This means I load the coarsest mesh into Fluent and apply the mesh adaption near the boundary to get a mesh topology similar to the one in the picture.
3. Converting Cells with Hanging Nodes / Edges to Polyhedra via tui command "mesh → polyhedra → convert-hanging-nodes". This should convert the hexahedron cells adjacent to a region of smaller cells to polyhedron cells with 9 faces each (provided a size ratio of 2:1) and avoid hanging nodes.
   Unfortunately, the menu itempolyhedra is not available in my fluent version. Strange...

With the focus on LES or later DNS, which approach would be the best in terms of accuracy?
I would simply test both methods, but since this is not really part of my project I hope that someone else has some experience to share on this topic.
Maybe there are even more possibilities or number 2 and 3 on my list are treated in the same way by Fluent or they will not work the way I expect. Feel free to correct me.

Edit:
Apparenty, converting hanging node cells to polyhedra is only possible with a 3d-mesh.