This was an interesting CFD case we saw from a user when using boundary layers:
"All the surfaces not dependent on the BL are fine, and re-meshing other volumes is fine too.
There’s something that breaks when swapping out the volumes for the BL’s that have a common surface that is re-meshed during the process."
Then they found this solution:
"I’m happy to report the new mesh has been running for a couple of days now.
We determined that fundamentally Trelis handled the geometry change without any particular problems; however, order of operation was critical in an unexpected way.
It appears that defining Boundary Layers after forming the merged and imprinted geometry allows for a robust ability to modify mesh definitions and commit meshing operations in any order with the BL code not throwing an error.
On the other hand if the BL was defined before a connecting volume is changed then to remesh the unchanged volume after merging and imprinting you must start with the existing volume with the BL on it before meshing the new volume.
As long as you mesh the volume with the BL defined on it first then you can mesh the new volumes without any problems."