Discussion Forum

Using only the drawing tools within Comsol, I would be able to create that geometry by building multiple cylinders and using the array and difference operations.

You should consider whether (1) the holes are essential to the problem you want to solve and (2) whether symmetry can be used to reduce the effort of drawing and computing the problem.

yes the holes are essential and affect the process greatly and the symmetry can be used. I want this holes to be 2D circles and to create a polar array and I can't do this 2 actions. Can you clarify how symmetry would help? Can you please write the actions in details as the geometry is the base for the simulation in my case? Thank you so much

In 6.3 there now is a ChapGPT option that can help you code this geometry built. In 6.2 I would create a thin cylinder that cuts through the bigger cylinder, and use the Array and/or Rotate functions to copy this small cylinder up, down, and around, and make more cuts.

René has provided a bit more detail, and you can also go to

https://www.comsol.com/video/3d-geometry-tools-comsol-multiphysics

for a short tutorial on how to use the geometry construction tools.

About symmetry- you haven't shown the rest of the geometry but as drawn the cylinder has rotational symmetry so the problem might be solved in a pie-like domain with symmetry boundary conditions on the cut surfaces.

Using symmetry requires some thought but can really pay off in reduced computation time for a complex 3D geometry.

I don't know if it is relevant for your application but... I'll mention that for some physics it is possible to replace a thin perforated object with a (possibly internal) boundary condition defined on a surface drawn without any of the fine details; the grille condition in CFD is an example. When such an approach can be used, not only is geometry creation much quicker, but you save lots of time and memory on meshing and solving.

Jeff