Don't use Multizone for this geometry.nSince you have a repeating structure, use the smallest unit of the structure. I can see 4 cells on each edge. That means you have 4x4x4 = 64 times too much geometry. Take 3 planes and cut 1/4 of the way in from one corner to get a single cell, that will be much easier to mesh with inflation.nI have other software that can easily mirror a mesh. If I mirror the mesh 2 times in each direction, I will have recreated that geometry.nIf you can't figure out how to do that in ANSYS, you could just use 3 planes in each coordinate direction to slice the geometry into 64 pieces. Use Shared Topology to put them into a single part. Hopefully, each piece will mesh as nicely as a single cell does.n