Can Parametric Surfaces Be Turned Into Volumes?

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Hello

This question is pretty simple in nature. I am attempting to model a tube with a rectangular transition in the middle. There is a screenshot of the geometry in question below for context. I am working on COMSOL version 5.2a, so to create this geometry, I opted to do so using a parametric surface. I did so using a super ellipse parametric equation, and as it was a surface I wanted to turn it into a volume by unioning endcaps and using the convert to solid function on the union.

This workflow has failed repeatedly. As such I attempted to see if I could get convert to solid to work for more simple cases, and defined a simpler hollow cylinder as a parametric surface and attempted to utilize union and convert to solid to turn it into a volume. This also failed, and subsequent attempts with trying to turn other simple surfaces into volumes like cubes have also not worked.

I have only seen videos of convert to solid being utilized in 2d, so I wanted to ask if utilizing convert to solid on 3d surfaces is fruitless as I have had no successful attempts and cannot find any examples online.

If so, does anyone have any suggestions for creating smooth transitions in 5.2a? I do not have access to a loft function in this version it seems, and I also can only import STL's, rather than another form of CAD file. I have had very poor experiences with the quality of STL imports, so the idea of creating the geometry in Solidworks and importing it also is failing me.

Thank You



2 Replies Last Post May 1, 2026, 2:22 p.m. EDT
Acculution ApS Certified Consultant

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Posted: 14 hours ago May 1, 2026, 2:42 a.m. EDT

Can you upload a file, perhaps just the cylinder case?

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René Christensen, PhD
Acculution ApS
www.acculution.com
info@acculution.com
Can you upload a file, perhaps just the cylinder case?

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Posted: 2 hours ago May 1, 2026, 2:22 p.m. EDT
Updated: 2 hours ago May 1, 2026, 2:23 p.m. EDT

Can you upload a file, perhaps just the cylinder case?

Here is an example file. The convert to solid function is disabled because it causes everything to disappear, but you can enable it to see this.

I also have the circular end caps as larger than the radius of the cylinder as attempting to union a circle of the exact radius of the cylinder also causes it to disappear. If you need anything else or more context please let me know.

>Can you upload a file, perhaps just the cylinder case? Here is an example file. The convert to solid function is disabled because it causes everything to disappear, but you can enable it to see this. I also have the circular end caps as larger than the radius of the cylinder as attempting to union a circle of the exact radius of the cylinder also causes it to disappear. If you need anything else or more context please let me know.

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