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March 23, 2018, 07:45 |
twoLiquidMixingFoam: alpha becomes unbounded
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#1 |
Member
Join Date: Apr 2017
Posts: 68
Rep Power: 9 |
Hi.
I get an alpha at 1.6. I think alpha is supposed to be bounded between 0 and 1. I have the following settings in fvSolutions: Code:
"alpha.water.*" { nAlphaCorr 1; nAlphaSubCycles 2; cAlpha 1; icAlpha 0; MULESCorr yes; nLimiterIter 10; alphaApplyPrevCorr yes; solver smoothSolver; smoother symGaussSeidel; tolerance 1e-8; relTol 0; minIter 1; } |
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March 23, 2018, 09:09 |
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#2 |
Senior Member
Uwe Pilz
Join Date: Feb 2017
Location: Leipzig, Germany
Posts: 744
Rep Power: 15 |
This is far to less information. We need your case for telling something valuable.
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Uwe Pilz -- Die der Hauptbewegung überlagerte Schwankungsbewegung ist in ihren Einzelheiten so hoffnungslos kompliziert, daß ihre theoretische Berechnung aussichtslos erscheint. (Hermann Schlichting, 1950) |
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March 23, 2018, 09:22 |
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#3 | |
Member
Join Date: Apr 2017
Posts: 68
Rep Power: 9 |
Quote:
Maybe a picture can explain the case somewhat. The following shows my alpha, scaled from 1 to its max value (so the problem area shows easily) alphaProblem.jpg It is a flow of two fluids in a tank, and there is an obstacle at the top. The flow is going from right to left. Edit: I might add that the phase equal to 1 is at the bottom, so the part that is larger than 1 comes from nowhere. Maybe not relevant, but in case: The top BC for U infront of the obstacle is "inletOutlet" with internalField. In practice only the zeroGradient part is activiated in this area, since the flow goes up. The rest of the top as slip BC. This is a result of lots of trial and error. Slip over the whole does not work (Get blowup at a single cell at the corner of the obstacle infront cloeses to the screenm which is a symmetryPlane side). Inlet outlet over the full top gave very strange results. Last edited by kaaja; March 24, 2018 at 05:32. |
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