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!