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3.5 and 4.1 solver difference?

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I have a model, which can be solved in 4.1.

The same setting in 3.5, then the model doesn't converge.

I load the 3.5 version model in 4.1 and add a new study. It converge again.

Who knows the difference between the solvers in 3.5 and 4.1?

Thanks

2 Replies Last Post Mar 9, 2012, 11:57 p.m. EST

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Posted: 1 decade ago Mar 9, 2012, 9:32 p.m. EST
which of the solvers you use? what are the settings? if you are using default, they might be different.
which of the solvers you use? what are the settings? if you are using default, they might be different.

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Posted: 1 decade ago Mar 9, 2012, 11:57 p.m. EST
You are right. The 3.5 is using the PARDISO, while 4.1 is using MUMPS.

I am coupling electrostatics, Nernst-Planck with Navier-Stokes equation.

When just with electrostatics and nernst-planck, 3.5 can give a correct answer.
Also with just using Navier-Stokes equation, 3.5 is fine too.

However, when I coupled them together, 3.5 didn't converge and said that the error is beyond tolerance.
You are right. The 3.5 is using the PARDISO, while 4.1 is using MUMPS. I am coupling electrostatics, Nernst-Planck with Navier-Stokes equation. When just with electrostatics and nernst-planck, 3.5 can give a correct answer. Also with just using Navier-Stokes equation, 3.5 is fine too. However, when I coupled them together, 3.5 didn't converge and said that the error is beyond tolerance.

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