Simulation Errors - Problem with CAD Import

CAD Mode Support
1

Hello,

I am getting the following 2 errors, and as a result I am unable to run my natural ventilation simulation. I have no idea how to fix these, can someone help?

Error 1
Natural convection inlet/outlet 3 has face assignments that do not belong to a volume region.

Error 2
A setup with at least 10 regions is being used in a single-region analysis type. Please ensure that only one fluid region exists and that all other bodies are assigned to an advanced concept. If you have already meshed your geometry, ensure that all the meshing regions except one are cell zones.

In the mesh settings, I also get the following warning which seems related, but I am unsure.
Sheet bodies detected. To address this error, I went back to my rhino model and solidified (i.e. added thickness) to all my 2D surfaces, but I ended up getting other errors.
“The model contains sheet bodies (surface data). An internal mesh requires solid regions only. Try to solidify all surface parts.”

I also don’t know how to create a flow volume extraction since my geometry complex (essentially a roof with an opening and perforated brick walls).

2

Hi, thank you for using the forum.

I had a look at your case and your CAD needs quite some cleanup. To perform a simulation your CAD must meet the following requirements:

  1. It must be Watertight. There must be no holes.
  2. The CAD must contain only solid parts i.e Sheet bodies must not be detected.

I would recommend you to read the following articles as they will guide you more on CAD preparation:

Regarding the errors:
A convective heat analysis can only contain a single fluid region. Therefore the boundary conditions can also be assigned only to the walls of the fluid region. In your case, the BCs are assigned to surfaces that do not belong to the fluid region. Therefore you need to make sure that there is only one single fluid region(volume) in your domain

For flow extraction, please have a look at the below two articles:

I hope this helps.
Best regards,
Paresh