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Increasing performance changing AMG parameters in Star-CCM+

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Old   March 22, 2012, 08:51
Default Increasing performance changing AMG parameters in Star-CCM+
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Hi. I am simulating a rotating machine with heat tranfer and heat conduction. The pressure takes long before converging. Is there any parameter in the AMG solver I could change to increase the performances? (the BicGstab is already on)
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Old   March 23, 2012, 10:23
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For the Multi-Grid, I think that you may be able to increase the group size to improve convergence speed.

I would also experiment with changing the under-relaxation factors.
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Old   March 26, 2012, 05:13
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I saw some improvment in the convergence behavior when increasing the group size. Thanks for your advice. I changed the group size for the pressure. Do you think I could expect further improvments when changing the group size on the momentum? Does the group size affect the memory requirement?
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Old   March 26, 2012, 14:09
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I'm not sure whether increasing the group will directly affect the memory requirement.

Multigrid methods take advantage of the ability of coarser grids to damp transients more quickly. Without knowing more about your simulation its tough to say how the momentum performance may change. I guess its worth a try, right?
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Old   March 26, 2012, 18:45
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Quote:
Originally Posted by archeo View Post
Hi. I am simulating a rotating machine with heat tranfer and heat conduction. The pressure takes long before converging. Is there any parameter in the AMG solver I could change to increase the performances? (the BicGstab is already on)

By pressure do you mean continuity( mass convergence)?

If yes then there are lots of other factors that affect it. The heavy impact comes from skew or non-orthogonality. If possible improve the mesh.
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