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Symmetry boundary condition results

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Hi,

I'm modelling pressure drop in a channel and I use symmetry in the middle of the channel along the fluid flow. Since I'm using symmetry, I halve the flow rate which is an input at the inlet. When I want to find the pressure drop, I use the average surface and I have two options for dataset. One is the solution and the other one is the mirror. If I use the mirror, the pressure drop is half.

Could someone please let me know if I should halve the flow rate at the inlet when I'm using symmetry? Also, which dataset I should use to find the total pressure drop (full area of the cross-section)?

Thanks and Regards

A little bit of description: If I use mirror, the pressure drop is half. I tried to map the flow rate to see if the results are close to my input flow rate but wasn't very intuitive, because it seems like I should choose the solution and not the mirror. For example if the flow rate is 1.6(m3/s), I add 0.8(m3/s), then in the derived values, I choose the surface and solution as the dataset, and the (velocity * area) gives me almost the same flow rate. But if I choose the mirror (in order to choose the full area), the (velocity * area) gives half of the flow rate.


0 Replies Last Post Feb 8, 2024, 7:04 a.m. EST
COMSOL Moderator

Hello Saba M

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