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problems with a DES (k-epsilon model) implementation |
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April 7, 2009, 05:12 |
problems with a DES (k-epsilon model) implementation
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#1 |
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Sven Degner
Join Date: Mar 2009
Location: Zürich
Posts: 55
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Hi everyone,
at the moment I will try to implementation the k-eps model in a DES . The base of code are the DES SpalartA, white the two new components k and epsilon. my epsilon (Ldes) is defined as : if (mesh_.changing()) { epsilon_ = pow(k_,(3/2))/min(CDES_*delta(),pow(k_,3/2))/epsilon_); } as next I add the two equations tmp<fvScalarMatrix> epsEqn ( fvm::ddt(epsilon_) + fvm::div(phi_, epsilon_) - fvm::Sp(fvc::div(phi_), epsilon_) - fvm::laplacian(DepsilonEff(), epsilon_) == C1_*G*epsilon_/k_ - fvm::Sp(C2_*epsilon_/k_, epsilon_) ); and tmp<fvScalarMatrix> kEqn ( fvm::ddt(k_) + fvm::div(phi_, k_) - fvm::Sp(fvc::div(phi_), k_) - fvm::laplacian(DkEff(), k_) == G - fvm::Sp(epsilon_/k_, k_) ); Now the problem with the case, after a successful wmake libso compilation, its not possible to run the code. After the start with oodles, its occurs this error messages Courant Number mean: 0 max: 0.00126355 #0 Foam::error:rintStack(Foam::Ostream&) in "/usrfem/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so" #1 Foam::sigFpe::sigFpeHandler(int) in "/usrfem/femsys_local/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so" #2 ?? in "/lib64/libc.so.6" #3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) in "/usrfem/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libOpenFOAM.so" #4 void Foam::divide<Foam::fvPatchField, Foam::volMesh>(Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) in "/usrfem/femsys_local/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libincompressibleLESModels.so" #5 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam:perator/<Foam::fvPatchField, Foam::volMesh>(Foam::tmp<Foam::GeometricField<doub le, Foam::fvPatchField, Foam::volMesh> > const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) in "/usrfem/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libincompressibleLESModels.so" #6 Foam::incompressible::LESModels::kEpsilon::correct (Foam::tmp<Foam::GeometricField<Foam::Tensor<doubl e>, Foam::fvPatchField, Foam::volMesh> > const&) in "/usrfem/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libincompressibleLESModels.so" #7 Foam::incompressible::LESModel::correct() in "/usrfem/OpenFOAM/OpenFOAM-1.5/lib/linux64GccDPOpt/libincompressibleLESModels.so" #8 main in "/usrfem/OpenFOAM/OpenFOAM-1.5/applications/bin/linux64GccDPOpt/oodles" #9 __libc_start_main in "/lib64/libc.so.6" #10 Foam::regIOobject::readIfModified() in "/usrfem/OpenFOAM/OpenFOAM-1.5/applications/bin/linux64GccDPOpt/oodles" Floating exception I hope I get some tips with this message or any helps how they test the turbulence model of errors best regards Sven |
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April 8, 2009, 04:13 |
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#2 |
Senior Member
Mattijs Janssens
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April 14, 2009, 08:53 |
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#3 |
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Sven Degner
Join Date: Mar 2009
Location: Zürich
Posts: 55
Rep Power: 17 |
hi mattijs,
thanks for the link, now its works fine sven |
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April 14, 2009, 09:41 |
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#4 |
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Daniel WEI (老魏)
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Hi, sven!
I'm very interested in your implementation, what's going on and which testCase do you use? Regards, Daniel
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~ Daniel WEI ------------- Boeing Research & Technology - China Beijing, China |
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April 14, 2009, 11:08 |
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#5 |
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Sven Degner
Join Date: Mar 2009
Location: Zürich
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Hi Daniel,
before I start with some test case, I will try to implantation a flux blending between CDF and upwind. In my opinion is the best test case cube with 3 cyclic patches in three mesh sizes with the target to compare the isotropic turbulence. After this I will try a practice case like mirror of a car, something like this. But the next step is the flux blending........... Sven |
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April 18, 2009, 07:00 |
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#6 |
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Fabian Braennstroem
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Hi Sven,
did you take a look at localBlended scheme? It should be suitable for this case. Fabian |
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April 21, 2009, 11:31 |
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#7 |
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Sven Degner
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Hi braennstroem ,
the idea with the localblended sounds good and its definitely the simplest way for me, thanks for that! Sven |
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April 30, 2009, 08:32 |
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#8 | |
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Daniel WEI (老魏)
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Hi Sven,
How's it going? I saw you have added the new L_DES scale, what is your reference papers, can you email me a copy of them? EMail: LAKEAT AT GMAIL DOT COM Quote:
Thank you! Daniel
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~ Daniel WEI ------------- Boeing Research & Technology - China Beijing, China |
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May 4, 2009, 12:04 |
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#9 |
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Sven Degner
Join Date: Mar 2009
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hi lakeat,
thats exactly what I try do. based of a empirical function like this will I switch or mix the both schemes (upwind / central) ! (sorry for the bad picture ! klick to enlarge) [TARVIN SHUR STRELETS SPALART (2002) Upgrades in the DES of complex turb. flow] www.springerlink.com/index/m516557444083t38.pdf when everything got a god idea for the implementation of the procedure or a similary example please post that here. thx Sven |
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May 4, 2009, 12:09 |
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#10 |
Member
Sven Degner
Join Date: Mar 2009
Location: Zürich
Posts: 55
Rep Power: 17 |
Hi braennstroem ,
the idea with the localblended sounds good and its definitely the simplest way for me, thanks for that! Sven |
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May 4, 2009, 12:13 |
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#11 |
Member
Sven Degner
Join Date: Mar 2009
Location: Zürich
Posts: 55
Rep Power: 17 |
hi lakeat,
thats exactly what I try do. based of a empirical function like this will I switch or mix the both schemes (upwind / central) ! (sorry for the bad picture ! klick to enlarge) [TARVIN SHUR STRELETS SPALART (2002) Upgrades in the DES of complex turb. flow] www.springerlink.com/index/m516557444083t38.pdf when everything got a god idea for the implementation of the procedure or a similary example please post that here. thx Sven |
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May 5, 2009, 08:56 |
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#12 |
Senior Member
Daniel WEI (老魏)
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I cannot download it, it's not free for my university. Can you email me a copy, thanks a bunch.
And did you notice the S-A model differences between
Have you tried IDDES, it seems the length scale has changed a lot. About the mixture of two schemes, is it stable and is it very NECESSARY for the simulation? I doubt that. Any ideas?
__________________
~ Daniel WEI ------------- Boeing Research & Technology - China Beijing, China |
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May 15, 2009, 13:42 |
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#13 |
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Philippe B. Vincent
Join Date: Mar 2009
Location: Quebec, Canada
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Hi Daniel, Sven, Fabian and other DES players,
Your work on DES implementation is very interesting. I was wondering if any of you tried to implement a DES-SST model? The proposed model by Strelets et al (AIAA Paper 2001-0879) is interesting. There is also a "shielded" formulation for that model, similar the DDES implementation in the Spalart-Allamaras model. That latter DDES-SA model can easily be implemented from the DES-SA already available in OpenFOAM (Ask me if you want to test my DDES version), but I would very much like to test the DES-SST model but the programming effort is much bigger About the mix between upwind and central, I read a recent article from Bombardier aerospace (not available yet) where they use the parameter fd (from the Spalart-Allmaras DDES formulation) to blend the schemes. Maybe it would be something to consider since it does not require additional calculation in the model. fd=0 actually forces the RANS mode while fd=1 is equivalent to DES97, and most likely to LES mode. I will try to implement that blending in my DDES-SA model by looking at localBlended scheme as suggested by Fabian, but if you can provide further help for that it would be much appreciated. Regards, Philippe |
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May 15, 2009, 23:03 |
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#14 |
Senior Member
Daniel WEI (老魏)
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Hi Philippe,
Good Morning from China! 1. DDES also includes a low Reynolds number correction, did you notice it? 2. IDDES is really a great idea, a very timely revision to DES concerning LLM. But I lose my idea now about the length scale redefinition, will the cube-root approach violate the IDDES spirit? 3. I'm shocked to find that ANSYS-12.0 has been released with DDES already in it, (even with a option based on SST), sigh... after all, it is Mr. Menter who is working for them with a high frequency activities with DESIDER. You know I once talked to my advisor, boasting that opensource like OpenFOAM is more up-to-date than commercial software, now I realize it is not so always, it depends. Regards
__________________
~ Daniel WEI ------------- Boeing Research & Technology - China Beijing, China |
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May 16, 2009, 12:56 |
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#15 |
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Fabian Braennstroem
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Hi Philippe,
you can try to add to 'createFields' file something like: volScalarField localInterface= reinterpret_cast<Foam::incompressible::RASModels:: kOmegaSST_Y*>(turbulence.operator->())->HybInterface(); where HybInterface() is a public member function in your model (in this case "kOmegaSST_Y". Before the calculation of the momentum equations you would calculate the surfaceScalarField: Info << "Into UBlending" << endl; surfaceScalarField surfLocalInterface = fvc::interpolate(localInterface); surfaceScalarField UBlendingFactor ("UBlendingFactor",surfLocalInterface); Fabian |
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May 19, 2009, 10:43 |
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#16 |
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Philippe B. Vincent
Join Date: Mar 2009
Location: Quebec, Canada
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Hi,
Daniel, I didn't know for CFX-12, it's interesting. I think will soon upgrade to CFX-12, so I might be able to test the DDES. But in my opinion, the DES-SST implemented in CFX-11 was already a DDES formulation. Fabian, thanks for the answer, I'll look into that. Are any of you going to be at the Workshop in Montreal? |
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November 28, 2017, 07:17 |
can you send me kEpsilonDES.C?
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#17 |
New Member
马国祯
Join Date: Apr 2017
Posts: 10
Rep Power: 9 |
hi sven82,
I am doing the same as you, to implement the k-epsilon model in DES. May you send me your file "kEpsilonDES.C" and "kEpsilonDES.H"? i am new to Openfoam ,and am studying it, thank you so much! my address is "npu_magz@163.com" Last edited by magz; November 28, 2017 at 07:19. Reason: best regards |
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