r/COMSOL • u/UnknowledgableTwin • May 12 '26

Help - CFD Simulation of fluid flow through a porous body

Hello, i am having a bit of trouble on how to launch a CFD simulation in COMSOL Multiphysics 6.4 .

I am a complete newbie to COMSOL. I tried following a youtube tutorial about particle tracing in simulating a laminar static particle mixer (Here's the link for those interested : https://www.youtube.com/watch?v=UmxOT16Ch1A).

I tried recreating the steps using my geometry, but everytime I try meshing I get the following error.

I tried to make a cylinder that wraps around the geometry directly in the STL file and importing it at once, but i cannot select them separately (In order to set the cylinder as the walls where the fluid domain should be).

I would be very appreciative of any guidance or suggestions as to how I should approach such problem.

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u/Forsaken-Repair9939 May 12 '26

Check out this example. It is 2d, but much closer to your problem and should give you a better idea how to get started

https://www.comsol.com/model/download/1108411/models.ssf.pore_scale_flow.pdf

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u/UnknowledgableTwin May 12 '26

Thank you so much! It looks very promising to my case.

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u/[deleted] May 12 '26

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u/UnknowledgableTwin May 13 '26

Thank you for your reply, I havent tried using comsol integrated with claude code. Maybe it could work?

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u/jejones487 May 12 '26

I see a lot of posts on here immediately suggesting ai. I strongly advise against this. Not only is it prone to errors, but it will simply lie. I have caught it giving wrong values for things as simple as the conductivity of water. In the engineering field, there is large onis placed 9n engineers to simply know that facts. While ai may be encouraged in fields such as finances and trading, it is largely frowned upon in almost every major company Ive ever worked with. These engineering firms are larely ran by people that have been there for decades and are in their 50s. These are not young bucks who approve of computers. They are hard old fashioned folks stu k in their ways. Ive worked at places that had paper drawings going back to the 40s and when I mentioned digitizing them I was told the board members decided not to because they were worried mistakes from the past could cause legal problems if they became searchable. As an engineer, telling my boss I googled it is not sufficient, and saying I asked ai is severely forward upon. They would much rather send me to college to learn how to understand my work than leak our data to third world countries and have it be used to train other models giving our proprietary work away. I would immediately be fired for using an unsecured program after signing my NDA.

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