Different results using Mixture model for 5.4 version and 5.2a version

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I am using Mixture to run for lubrication flow in journal bearing with cavitation. It is very interesting that when I used 5.2a version, I can get the correct answer. When I used 5.4 version, the result is simply wrong. I believe that 5.4 version has a problem in mixture model.


3 Replies Last Post Sep 11, 2019, 4:52 AM EDT

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Posted: 2 weeks ago Sep 10, 2019, 6:48 AM EDT
Updated: 2 weeks ago Sep 10, 2019, 6:48 AM EDT

I have noticed that since 5.4, the eqations for mixture model have been different from the earlier version. Perhaps there is some issues involved in there. Don't have any problem for bubbly flow model.

I have noticed that since 5.4, the eqations for mixture model have been different from the earlier version. Perhaps there is some issues involved in there. Don't have any problem for bubbly flow model.

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Posted: 1 week ago Sep 10, 2019, 9:07 AM EDT

I have found that it has something to do with the numerical diffusion. Still looking for appropriate set.

I have found that it has something to do with the numerical diffusion. Still looking for appropriate set.

Mats Nigam COMSOL Employee

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Posted: 1 week ago Sep 11, 2019, 4:52 AM EDT

Dear Shiuh-Hwa, The formulation for the mixture model was changed in v5.4. It is now formulated in terms of the volume-averaged velocity instead of the mass-averaged velocity used in prior versions. If you can share your model, we can check that it's consistently set up. Best regards, Mats Nigam

Dear Shiuh-Hwa, The formulation for the mixture model was changed in v5.4. It is now formulated in terms of the volume-averaged velocity instead of the mass-averaged velocity used in prior versions. If you can share your model, we can check that it's consistently set up. Best regards, Mats Nigam

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