Subtract – Surface Name Selection

- July 5, 2023 at 10:16 am
  
  Levente Bicskei
  Subscriber
  
  Hello!
  
  I have a room full of solid bodies, electronic components, etc. I want to study 3D air flow of the ventilation, so I just need the air volume, which I can create by subtracting the solid bodies from the air volume.
  
  Is it possible to somehow keep the names of the surfaces cut by the solid bodies? Since manually would be a nightmare to group name selections one by one for hundreds of surfaces.
  
  For example:
  I have air and solid1, solid2, solid3. If I subtract the solid1, solid2 and solid3 from air then I am left with only one air volume without face names (just the general "faces" without specific names). Is it possible to somehow keep the names "solid1 face", solid2 face", solid3 face", for which I can specify heat flux boundary conditions later?
  
  Thank you for your help!
- July 5, 2023 at 1:02 pm
  
  Rob
  Forum Moderator
  
  Possibly, if you're using Fluent Meshing. I've not tried this but don't see why it won't work: test on a simple model.
  Split the solids rather than subtract from the fluid zone. You'll have the fluid zone and all of the solids. Share Topology and go into Meshing. Mesh, and set the solid zones as "solid", fluid zone as "fluid". When you read into Fluent the surfaces between the zones will retain some of the solid label. In Fluent you can then delete the solid zones from your model leaving behind the fluid and labelled surfaces.
  I also suggest reviewing either the copy feature in boundary conditions or TUI journals to speed up setting all the bc's.