Areas on a surface to SimScale

Hi all,

I have a probably simple question, but I could not find a solution, so here it goes. I have a volume (a simple room) and I want to include some heat sources in the floor. The heat sources are simple rectangles, but they don’t fill the entire floor (they are the part of the floor the sun shines on through the windows). In my CAD software I would like to just draw these rectangles on the floor so I can select them later as boundary conditions in SimScale. However, the import from CAD only seems to process volumetric information so these rectangles get lost during import (I use STL)

Example project: SimScale

As a solution I now elevate these rectangles a bit (now I use 10 cm) so they actually form part of the volume, but this is kind of a dirty hack. It introduces a spatial structure in the geometry which really is not there. II can do the elevation just a few milimeters but this introduces a small spatial scale which requires a very fine grid.

Is there a way to generate a face on a face so to speak? What would be the steps in CAD and what import format? My CAD software is FreeCad (I also tried with sketchup)

Thanx for any help!


Usually this function is called split face (or some variant) in CAD softwares. Have you tried this for instance? Dividing, Splitting, and Exploding Lines and Faces | SketchUp Help

Let us know if it works!

1 Like

Thank you very much Ricardo. I can do it without problems in sketchup, but the split face is “lost” when importing from STL, my room “arrives” in SimScale as a straight volume with single faces. It somehow makes sense, as a line on a surface is not part of the volume definition itself. But it requires the trick I described.

Kind regards, Claus