Hello. I have a CAD body to to define a volume for “Volume custom sizing” mesh refinement. My domin is refined, but also the CAD body was meshed as well and the simulation cannot be created with this error:
“A setup with at least 2 regions is being used in a single-region analysis type. Please delete CAD regions that are irrelevant for the simulation. If all CAD regions are relevant, ensure that only one region is assigned to the material and that all other bodies are assigned to advanced concepts.”
How can I use a CAD body to perform volume refinement but then exclude that body from further meshing and simulation? I checked the docs and could not find the answer. Thanks!
Hi @hamish_234, thanks for posting on the forum and welcome to the SimScale Community 
This message usually appears when users forget to delete solid bodies apart from the flow region when running single-region analysis types (e.g. Incompressible, Compressible, Convective Heat Transfer…). These are not concerned with solid-fluid interactions and you’ll only be able to simulate using a single flow volume.
Is this your case?
As a sidenote, always make sure to add your project’s link when posting - this will make the troubleshooting task smoother for us! For more information, take a look here: Guide to Clear and Understandable Forum Posting
Cheers,
Igor
I am not allowed to post links, it seems. The project is called “2d jetfork”.
I am trying to simulate only 1 flow region yes. But I need a CAD body to specify a region to refine. The primitives (sphere, etc) are too simple. How can I use a CAD body to specify a refinement volume?
Hi @hamish_234, to post links you just need to copy the URL from the browser with your project open. Here’s a link to yours: https://www.simscale.com/workbench/?pid=1377320419977318098
Unfortunately you’d only be able to define refinements on regions using the geometry primitives option however since you have a 2D extruded model, refining would be the same as partitioning surfaces and applying refinements to them - then you could just apply a surface custom sizing: Standard Mesher | Meshing for CAE | Documentation | SimScale
Thanks @igaviano. By doing boolean unite of the geometry, the surfaces became split in the places I need and then I applied surface refinements to achieve a fine mesh where I need it. The simulation works now.