PBiCG VS smoothsolver
Posted March 31, 2017 at 11:51 by kindle
Updated May 11, 2017 at 09:21 by kindle (OF-4.x and Foam-extend have implemented this solver)
Updated May 11, 2017 at 09:21 by kindle (OF-4.x and Foam-extend have implemented this solver)
Namings of libraries are different in OpenFOAM and foam-extend. Well. BiCGStab is needed in U solver of viscoelasticFluidFoam
And this PBiCGStab is implemented also in the OF-4.x and foam-extend (go downstairs from the post). More specifically in OF-4.x it is added (https://github.com/OpenFOAM/OpenFOAM-4.x/commit/1ca4bbf1d288075a76940d58fdf61cbfc49298ee) and in foam-extend it is modified (https://github.com/OpenFOAM/OpenFOAM-dev/commit/c339d3018c98cb67c3455ab09db316c7c0618d5c).
And this PBiCGStab is implemented also in the OF-4.x and foam-extend (go downstairs from the post). More specifically in OF-4.x it is added (https://github.com/OpenFOAM/OpenFOAM-4.x/commit/1ca4bbf1d288075a76940d58fdf61cbfc49298ee) and in foam-extend it is modified (https://github.com/OpenFOAM/OpenFOAM-dev/commit/c339d3018c98cb67c3455ab09db316c7c0618d5c).
Quote:
Originally Posted by sharonyue
Hello guys!
From my simulations, I found these matrix solver's un-normal behavior(for my passive scalar transport equations), especially for PBiCG.
All in all, PBiCG is fast but not stable, smoothsolver is stable but slow.
for example:
I add 6 passive scalar transport equations into my solver. I found PBiCG is quite fast to get to Final residual. Usually under 20 times to 1e-16. But for smoothsolver, it takes nearly thousands times. However, sometimes smoothsolver can not reach to final residual. So we can see this PBiCG is quite fast!
However, PBiCG is not stable. I dont know if anyone experienced this before, Long time ago my solver blowed up in parallel but succeeded in serial. Then I switch PBiCG to smoothsolver. It worked out. And the results are quite good!
This time, Im facing kind of similar problem too. Cuz I need to run long long time, I want it to be quite fast. So I use PBiCG. But it blows up! But smoothsolver runs smoothly!
Im not familiar with matrix solver. I barely know nothing about this. So if someone can clarify this or have something to discuss. I would like to hear any suggestions!
Best,
From my simulations, I found these matrix solver's un-normal behavior(for my passive scalar transport equations), especially for PBiCG.
All in all, PBiCG is fast but not stable, smoothsolver is stable but slow.
for example:
I add 6 passive scalar transport equations into my solver. I found PBiCG is quite fast to get to Final residual. Usually under 20 times to 1e-16. But for smoothsolver, it takes nearly thousands times. However, sometimes smoothsolver can not reach to final residual. So we can see this PBiCG is quite fast!
However, PBiCG is not stable. I dont know if anyone experienced this before, Long time ago my solver blowed up in parallel but succeeded in serial. Then I switch PBiCG to smoothsolver. It worked out. And the results are quite good!
This time, Im facing kind of similar problem too. Cuz I need to run long long time, I want it to be quite fast. So I use PBiCG. But it blows up! But smoothsolver runs smoothly!
Im not familiar with matrix solver. I barely know nothing about this. So if someone can clarify this or have something to discuss. I would like to hear any suggestions!
Best,
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