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GAMG vs. PCG in fvSolution

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Old   July 21, 2011, 04:39
Default GAMG vs. PCG in fvSolution
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hi foamers,

i'm working with two domains of exactly same geometry and case configurations. one domain has 150000 cells, the other about 6*10^6 cells.

in the coarse domain case the GAMG solver needs about 30 iterations for one timestep (nCellsInCoarsestLevel = 1000). on the other hand, if i choose PCG the calculation needs 230 iterations.

in the fine domain case it's the opposite: PCG needs about 1000 iterations but GAMG does need more (maxIter limitation at 1500, various nCellsInCoarsestLevel).

what's your experience with GAMG? any tips what i could try?

best regards
grandgo
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Old   November 13, 2015, 09:58
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Antony Ashley Raja B
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Hi,

Did you find any answer?

I am solving a external flow simulation. When i increase the number of layers and decrease the min thickness close to 9.6e-06,in a GAMG solver the iterations reach close to 1000 and crashes but on the other hand PCG works very well.

Is there any reason behind.

Thanks,
Antony
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