View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0001209 | OpenFOAM | Bug | public | 2014-03-06 22:54 | 2015-04-30 20:19 |
| Reporter | albertop | Assigned To | henry | ||
| Priority | normal | Severity | minor | Reproducibility | N/A |
| Status | resolved | Resolution | fixed | ||
| Platform | Linux | OS | openSUSE | OS Version | 13.1 |
| Summary | 0001209: Should MULES use alphaMax rather than 1 with particulate models? | ||||
| Description | The MULES call in twoPhaseEulerFOAM / twoPhaseSystem.C is MULES::explicitSolve ( geometricOneField(), alpha1, phi_, alphaPhic1, Sp, Su, 1, 0 ); However in the previous implementation of twoPhaseEulerFoam, the bounds for alpha were set to 0 and alphaMax in the case of particulate flows, where alphaMax < 1. Shouldn't this be the case also in the new twoPhaseEulerFoam? | ||||
| Tags | No tags attached. | ||||
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I thought about it and concluded that it wasn't clear that alphaMax is a preferable because it is a soft limit; the phase-fraction may exceed alphaMax without serious problem. If alphaMax is used for the MULES limiter upwind differencing would be used anywhere alpha exceeds alphaMax; do you think that would be a good thing? |
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I see your point. Indeed some models (Schaeffer, for example) let alphaMax be a soft limit, while others consider it as a hard limit (kinetic theory, Johnson and Jackson), so it's not clear. I asked because with models that consider it a hard limit, alpha is limited when it approaches alphaMax, to avoid divergence of the particle pressure. This in some cases leads to a phase pressure that isn't sufficient to prevent a further increase in alpha, which can become very high. If I understand it correctly, MULES should enforce alphaMax as a hard limit, and prevent this. |
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> If I understand it correctly, MULES should enforce alphaMax as a hard limit, > and prevent this Yes, provided the schemes (other than convection) are bounded schemes. For example if the laplacian is corrected on a non-orthogonal mesh MULES cannot currently guarantee boundedness as it operates only on the convection flux. Nevertheless I take your point and will change the MULES call to limit to alphaMax. |
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Resolved by commit 97056cd4664657296e7028756edc05cdb87b0e06 |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2014-03-06 22:54 | albertop | New Issue | |
| 2014-03-06 23:14 | henry | Note Added: 0002931 | |
| 2014-03-07 03:10 | albertop | Note Added: 0002932 | |
| 2014-03-07 08:43 | henry | Note Added: 0002935 | |
| 2014-03-07 23:40 | henry | Note Added: 0002938 | |
| 2014-03-07 23:40 | henry | Status | new => resolved |
| 2014-03-07 23:40 | henry | Resolution | open => fixed |
| 2014-03-07 23:40 | henry | Assigned To | => henry |
