View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000243 | OpenFOAM | Bug | public | 2011-07-08 15:45 | 2011-07-08 17:10 |
| Reporter | Assigned To | henry | |||
| Priority | normal | Severity | minor | Reproducibility | N/A |
| Status | resolved | Resolution | fixed | ||
| Summary | 0000243: Possible bug in SpalartAllmaras::DnuTildaEff() | ||||
| Description | Is there perhaps a bug in the RANS Spalart-Allmaras turbulence models (both the incompressible and compressible versions) in the computation of DnuTildaEff()? Take the incompressible version as an example: tmp<volScalarField> SpalartAllmaras::DnuTildaEff() const { return tmp<volScalarField> ( new volScalarField("DnuTildaEff", nuTilda_/sigmaNut_ + nu()) ); } From the SA equations one would expect that also nu() to be divided by sigmaNut_, i.e. tmp<volScalarField> SpalartAllmaras::DnuTildaEff() const { return tmp<volScalarField> ( new volScalarField("DnuTildaEff", (nuTilda_ + nu())/sigmaNut_) ); } | ||||
| Tags | No tags attached. | ||||
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It would not be correct to scale the laminar viscosity which relates to the laminar part of the stress and not the turbulence modeling. |
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Ok, but according to eq (267) in the Ashford thesis the entire diffusion term should be scaled: $\frac{1}{\sigma} \nabla \cdot \left( \nu + \tilde{nu} \right) \nabla \tilde{nu} \right)$. This is indeed also how you implement it in the LES version: tmp<fvScalarMatrix> nuTildaEqn ( fvm::ddt(nuTilda_) + fvm::div(phi(), nuTilda_) - fvm::laplacian ( (nuTilda_ + nu())/sigmaNut_, nuTilda_, "laplacian(DnuTildaEff,nuTilda)" ) - Cb2_/sigmaNut_*magSqr(fvc::grad(nuTilda_)) == Cb1_*STilda*nuTilda_ - fvm::Sp(Cw1_*fw(STilda, dTilda)*nuTilda_/sqr(dTilda), nuTilda_) ); Cheers Claes |
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Sorry, the laminar nu for the laminar stress should not be scaled but can be scaled for the nuTilda equation according to the modeling. I will change the code to be consistent and push the fix. Thanks for reporting. |
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Resolved by commit e8c6db8899c73bdb039eeb2cc6f8e6808b0ccbbb |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2011-07-08 15:45 |
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New Issue | |
| 2011-07-08 15:51 | henry | Note Added: 0000526 | |
| 2011-07-08 15:51 | henry | Status | new => closed |
| 2011-07-08 15:51 | henry | Assigned To | => henry |
| 2011-07-08 15:51 | henry | Resolution | open => fixed |
| 2011-07-08 16:05 |
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Note Added: 0000527 | |
| 2011-07-08 16:05 |
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Status | closed => feedback |
| 2011-07-08 16:05 |
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Resolution | fixed => reopened |
| 2011-07-08 16:16 | henry | Note Added: 0000528 | |
| 2011-07-08 17:10 | henry | Note Added: 0000529 | |
| 2011-07-08 17:10 | henry | Status | feedback => resolved |
| 2011-07-08 17:10 | henry | Resolution | reopened => fixed |
