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Which AMG Linear Solver

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Old   March 11, 2011, 10:42
Default Which AMG Linear Solver
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Tom Schmitz
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Hey,

I have a problem with solid body and a fluid flow. I use a segregated Solid Energy Model for the solid body. My Problem is that the temperatur changes just very very slowly. There a no big temperature changes due to the fluid. Any suggestions how i can improve the solver?

Thx
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Old   March 14, 2011, 03:41
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hi,

the AMG linear solver just solves the simultaneous algebraic equations obtained after discretization, changing it not going to affect ne thing.

If your simulation is giving wrong results you need to check the simulation setup and not be concerned the linear solver.

If you provide some more data regarding your simulation setup maybe someone can help u.
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Old   March 14, 2011, 04:43
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Thx for the answer. I didn't get wrong reluts and i could fix the problem by doing more iterations. Due to the fact that i'll have to calculate some variations i thought i could improve the speed a bit.

But another thing:
I want to calculate the heat flux over the outer cover of a cylinder.
1. I was using a Area Averaged Report with the Boundary Heat Flux field function over the interface. The result was zero.
2. I tried the same but with a cylinder section which had a smaler radius as the cylinder. The result was also zero.
3. I tried a heat transfer report over the interface. It was also zero.

After that i thought about the reason and got two ideas.
1. It is to small to be calculated.
2. There is something wrong with the interface. But what? I impried the bodies as i designed and the In-place Interface was created by StarCCM.
Do you have any idea where the problem could be?
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Old   March 14, 2011, 04:51
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To increase the speed with which your solution converges you might try by increasing your under-relaxation factors
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Old   March 20, 2011, 11:24
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Try to optimize your initial settings close to the solution you expect, that should improve your speed, too.
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