View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0001291 | OpenFOAM | Bug | public | 2014-05-12 16:59 | 2014-05-16 13:19 |
| Reporter | projectionist | Assigned To | henry | ||
| Priority | normal | Severity | minor | Reproducibility | always |
| Status | resolved | Resolution | fixed | ||
| Platform | Linux | OS | Ubuntu | OS Version | 12.04 |
| Summary | 0001291: [Diameter model IATE] sign error | ||||
| Description | In the transport equation of the IATE diameter model of twoPhaseEulerFoam there seems to be a wrong sign on the right hand side. In the code of OpenFOAM the right hand side of the transport equation for kappa has a negative sign. When looking up the interfacial area transport equation in (Yao and Morel, 2004) and (Ishii, Kim and Kelly, 2005) the right hand side has no negative sign. OpenFOAM uses the interfacial curvature (kappa) which corresponds to the interfacial area concentration (a_i) as follows a_i = alpha*kappa with the gas phase volume fraction alpha. Maybe, I made a mistake when deriving OpenFOAM's kappa equation from the transport equation of the interfacial aera concentration of the referred literature [Ishii et al. 2005, Eq. 15; Yao and Morel, 2004; Eq. 7]. If my derivation is correct the negative sign in ( - fvm::SuSp(R, kappai_) ) is wrong. | ||||
| Steps To Reproduce | // Initialise the accumulated source term to the dilatation effect volScalarField R ( ( (2.0/3.0) /max ( fvc::average(phase_ + phase_.oldTime()), residualAlpha_ ) ) *(fvc::ddt(phase_) + fvc::div(phase_.alphaPhi())) ); // Construct the interfacial curvature equation fvScalarMatrix kappaiEqn ( fvm::ddt(kappai_) + fvm::div(phase_.phi(), kappai_) - fvm::Sp(fvc::div(phase_.phi()), kappai_) == - fvm::SuSp(R, kappai_) ); | ||||
| Tags | No tags attached. | ||||
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The sign is correct but the constant is not. Combining the fvc::ddt(phase_) + fvc::div(phase_.alphaPhi()) from the LHS with the (2/3)*(fvc::ddt(phase_) + fvc::div(phase_.alphaPhi())) on the RHS results in -(1/3)*(fvc::ddt(phase_) + fvc::div(phase_.alphaPhi())) on the RHS, do you agree? |
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Resolved by commit 979da78e599961c304299c2d077100d03fcd51ce |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2014-05-12 16:59 | projectionist | New Issue | |
| 2014-05-13 15:40 | henry | Note Added: 0003057 | |
| 2014-05-16 13:19 | henry | Note Added: 0003060 | |
| 2014-05-16 13:19 | henry | Status | new => resolved |
| 2014-05-16 13:19 | henry | Resolution | open => fixed |
| 2014-05-16 13:19 | henry | Assigned To | => henry |
