View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0003020 | OpenFOAM | Bug | public | 2018-08-02 14:45 | 2018-08-15 14:45 |
| Reporter | tniemi | Assigned To | henry | ||
| Priority | low | Severity | minor | Reproducibility | always |
| Status | resolved | Resolution | fixed | ||
| Product Version | dev | ||||
| Fixed in Version | dev | ||||
| Summary | 0003020: Question regarding fvcDdtPhiCoeff and LTS | ||||
| Description | Hi In the commit (https://github.com/OpenFOAM/OpenFOAM-dev/commit/da787200a6b208cf3fc4dfaa48b4438a3a038c1b) the fvcDdtPhiCoeff was modified to use "mesh().time().deltaT()*mesh().deltaCoeffs()/mesh().magSf()" expression when calculating the tddtCouplingCoeff. It seems that this expression is also used with LTS-scheme where deltaT() will be 1 but the true dT can be much less. Is this intentional behavior or am I just reading the code wrong? To me it seems that if we run a transient case with a regular Euler and LTS with the same time step (dT << 1), in the regular case the tddtCouplingCoeff could be much larger than in the LTS case. Note: this is merely an observation made while reading the code. I don't have a test case to demonstrate any problems or effects. | ||||
| Tags | No tags attached. | ||||
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The change to fvcDdtPhiCoeff was necessary to handle very small time-steps correctly. This change may have implications for LTS; it is possible that the local time-step should be used in fvcDdtPhiCoeff or it may be preferable to not use ddtCorr for LTS at all if the local time-step is large enough; it is not necessary for steady-runs using the SIMPLE algorithm. Further testing is needed, please report any cases you have which benefit from any of the three choices. |
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Resolved by commit f5dd712c8497b03686dd3ed2ec3475539d5e801f |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2018-08-02 14:45 | tniemi | New Issue | |
| 2018-08-02 15:06 | henry | Note Added: 0009891 | |
| 2018-08-15 14:45 | henry | Assigned To | => henry |
| 2018-08-15 14:45 | henry | Status | new => resolved |
| 2018-08-15 14:45 | henry | Resolution | open => fixed |
| 2018-08-15 14:45 | henry | Fixed in Version | => dev |
| 2018-08-15 14:45 | henry | Note Added: 0009959 |
