View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0003339 | OpenFOAM | Patch | public | 2019-08-24 19:25 | 2019-08-26 17:41 |
| Reporter | davvalok | Assigned To | henry | ||
| Priority | low | Severity | trivial | Reproducibility | have not tried |
| Status | resolved | Resolution | fixed | ||
| Product Version | dev | ||||
| Fixed in Version | dev | ||||
| Summary | 0003339: Bug in Ergun drag model - Multiphase | ||||
| Description | In Ergun.C, following path: OpenFOAM-dev/applications/solvers/multiphase/reactingEulerFoam/interfacialModels/dragModels/Ergun/Ergun.C Line 69-72: Max(scalar(1) - pair_.continuous(), pair_.continuous().residualAlpha()) pair_.continuous().residualAlpha() should be pair_.dispersed().residualAlpha() since (scalar(1) - pair_.continuous()) refers to the dispersed pair in reality. | ||||
| Additional Information | This bug will also affect the GidaspowErgunWenYu drag model, if not being fixed. | ||||
| Tags | No tags attached. | ||||
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scalar(1) - pair_.continuous() relates to the dispersed phase fraction in a two-phase system but not in a multiphase system. Given that pair_.continuous() is used in the expression it makes sense that pair_.continuous().residualAlpha() is used. Can you provide a case which demonstrates the need to change the expression to use pair_.dispersed().residualAlpha() instead? |
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Hi Henry, Thank you for your reply. I am afraid I do not have a case for it, from the mathematical point of view it seems not very accurate. If you look at the WenYu.C you can see: volScalarField alpha2 ( max(scalar(1) - pair_.dispersed(), pair_.continuous().residualAlpha()) ); Which in the content of two phase system make sense. It might be better to use max(pair_.continuous(), pair_.continuous().residualAlpha()) for the content of multiphase? For Ergun I would suggest to use: scalar(1) - max(pair_.continuous(), pair_.continuous().residualAlpha()) instead of max(scalar(1) - pair_.continuous(), pair_.continuous().residualAlpha()) in Ergun.C. In either cases I guess the effect should be negligible if residualAlpha for phases are set correctly by user. |
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It is not clear how this change would affect accuracy. If you really think this change is necessary I can make it as I do not see how it will either improve or reduce accuracy or stability. |
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commit 7d6b7a78d758540fec56cd960a5a9f6aa11e7a91 |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2019-08-24 19:25 | davvalok | New Issue | |
| 2019-08-25 15:47 | henry | Note Added: 0010697 | |
| 2019-08-26 08:17 | davvalok | Note Added: 0010699 | |
| 2019-08-26 17:36 | henry | Note Added: 0010700 | |
| 2019-08-26 17:41 | henry | Priority | normal => low |
| 2019-08-26 17:41 | henry | Severity | minor => trivial |
| 2019-08-26 17:41 | henry | Category | Bug => Patch |
| 2019-08-26 17:41 | henry | Assigned To | => henry |
| 2019-08-26 17:41 | henry | Status | new => resolved |
| 2019-08-26 17:41 | henry | Resolution | open => fixed |
| 2019-08-26 17:41 | henry | Fixed in Version | => dev |
| 2019-08-26 17:41 | henry | Note Added: 0010701 |
