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What should I do to accelerate the solution

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Old   March 22, 2007, 06:33
Default What should I do to accelerate the solution
  #1
Ivan
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I have a very long elbow tube. Convergence is too slow(by mass eq). How could I accelerate the convergence.

StarCD 3.26

Regards!
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Old   March 22, 2007, 06:54
Default Re: What should I do to accelerate the solution
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Kasper Skriver
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Maybe use the traditional approach: Starting of with a 1'st order solver scheme, then switch to 2'nd order later. Try to adjust the under relaxation factors to a lower level. It might help.

Convergence on mass is generally slow.
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Old   March 22, 2007, 08:08
Default Re: What should I do to accelerate the solution
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Balduin Bankerotti
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You might have to create a more suitable mesh.
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Old   March 22, 2007, 09:13
Default Re: What should I do to accelerate the solution
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allan
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try amg solver
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Old   March 23, 2007, 09:18
Default Re: What should I do to accelerate the solution
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sidd
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If you are using second order differencing schemes, convergence will be slower in the beginning. But after reaching a stable stage, low relaxation factor doesn't help much and can be increased upto some level. But upto what level it is safe, i can't say as it depends very much on mesh, geometry and differencing scheme.

you can dynamically change the relaxation factor after a stable residual is reached.

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