In Hexa, both the block topology and the mesh can be smoothed to improve the overall block/mesh quality either in a certain region or for the entire model. The block topology can be smoothed to improve the block shape prior to mesh generation. This reduces the time required for development of the block topology model.

The geometry and its associative surfaces, curves, and points are all constraints when smoothing the block topology model. Once the block topology smoothing has been performed, you can smooth the mesh after specifying the proper edge-bunching parameters.

The quality criteria for smoothing are described in Pre-Mesh Quality in the Ansys ICEM CFD Help Manual.