[saman69]

Hello All.
I am trying to model a 2D channel (a rectangular domain) with subdomain (circle domain) and solid body using overset mesh in Ansys fluent. The Model was running when I used finer mesh for domain and courser mesh for subdomain using Ansys Meshing software. However, I got an error message when I used courser mesh for the domain and finer mesh for the subdomain. I tried to use Ansys ICEM for meshing using o-grid method for the subdomain. That method was not working as well. I got different errors. This is one of the error messages: “Build grid: Aborted due to critical error.” I attached one of the models which is meshed with ANSYS meshing and it modeled with fluent with this question.
I would greatly appreciate it if it would be possible to help me with it.

[Indra]

I think it has to do with the size difference between meshed at the interface.
The smaller domain has much bigger mesh at the boundary where it meets the other domain. At the boundary you should try to match the cell size as much as possible to keep it acurate.