no convergence with simplefoam
Everyone,i use simplefoam with standard kepsilon model to calculate the wind farm.when i type the command "simpleFoam",i get the following information:Create mesh for time = 0
Reading field p Reading field U > FOAM Warning : From function Field<Type>::Field(const word& keyword, const dictionary&, const label) in file /opt/openfoam210/src/OpenFOAM/lnInclude/Field.C at line 262 Reading "/root/OpenFOAM/root2.1.0/run/tutorials/incompressible/simpleFoam/wf39/0/U::boundaryField::inlet" from line 37 to line 16 expected keyword 'uniform' or 'nonuniform', assuming deprecated Field format from Foam version 2.0. Reading/calculating face flux field phi Selecting incompressible transport model Newtonian Selecting RAS turbulence model kEpsilon kEpsilonCoeffs { Cmu 0.028; C1 1.5; C2 1.92; C3 0.33; sigmak 1; sigmaEps 2.51; Prt 1; } No field sources present SIMPLE: convergence criteria field p tolerance 0.001 field U tolerance 0.001 field "(kepsilon)" tolerance 0.001 Starting time loop Time = 1 smoothSolver: Solving for Ux, Initial residual = 1, Final residual = 0.00644545010997, No Iterations 3 smoothSolver: Solving for Uy, Initial residual = 1, Final residual = 0.00464444535134, No Iterations 4 smoothSolver: Solving for Uz, Initial residual = 1, Final residual = 0.00708579374941, No Iterations 5 GAMG: Solving for p, Initial residual = 1, Final residual = 0.00735995074387, No Iterations 5 GAMG: Solving for p, Initial residual = 0.000167838426709, Final residual = 1.56259657312e06, No Iterations 6 GAMG: Solving for p, Initial residual = 2.2891470536e05, Final residual = 1.89675102907e07, No Iterations 4 GAMG: Solving for p, Initial residual = 4.86359414644e06, Final residual = 4.25624108873e08, No Iterations 4 time step continuity errors : sum local = 3.77016513754e08, global = 7.42217873687e09, cumulative = 7.42217873687e09 smoothSolver: Solving for epsilon, Initial residual = 1, Final residual = 0.00132760727343, No Iterations 2 smoothSolver: Solving for k, Initial residual = 1, Final residual = 0.00285899835651, No Iterations 2 bounding k, min: 0 max: 50.8029155486 average: 1.44150802022 ExecutionTime = 126.62 s ClockTime = 141 s Time = 2 smoothSolver: Solving for Ux, Initial residual = 0.446656785658, Final residual = 0.00197538615297, No Iterations 2 smoothSolver: Solving for Uy, Initial residual = 0.143272919974, Final residual = 0.000770220501008, No Iterations 3 smoothSolver: Solving for Uz, Initial residual = 0.159528815298, Final residual = 0.00142906124564, No Iterations 2 GAMG: Solving for p, Initial residual = 0.374485256388, Final residual = 0.00336921418749, No Iterations 6 GAMG: Solving for p, Initial residual = 0.00020659453246, Final residual = 1.28186320376e06, No Iterations 7 GAMG: Solving for p, Initial residual = 5.21634568919e05, Final residual = 4.89086468001e07, No Iterations 4 GAMG: Solving for p, Initial residual = 1.85185182451e05, Final residual = 7.29808804296e08, No Iterations 5 time step continuity errors : sum local = 5.23267147276e08, global = 9.14582863274e09, cumulative = 1.65680073696e08 #0 Foam::error::printStack(Foam::Ostream&) in "/opt/openfoam210/platforms/linuxGccDPOpt/lib/libOpenFOAM.so" #1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam210/platforms/linuxGccDPOpt/lib/libOpenFOAM.so" #2 Uninterpreted: #3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) in "/opt/openfoam210/platforms/linuxGccDPOpt/lib/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 "/opt/openfoam210/platforms/linuxGccDPOpt/lib/libincompressibleRASModels.so" #5 Foam::tmp<Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> > Foam::operator/<Foam::fvPatchField, Foam::volMesh>(Foam::tmp<Foam::GeometricField<doub le, Foam::fvPatchField, Foam::volMesh> > const&, Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh> const&) in "/opt/openfoam210/platforms/linuxGccDPOpt/lib/libincompressibleRASModels.so" #6 Foam::incompressible::RASModels::kEpsilon::correct () in "/opt/openfoam210/platforms/linuxGccDPOpt/lib/libincompressibleRASModels.so" #7 at /opt/openfoam210/applications/solvers/incompressible/simpleFoam/simpleFoam.C:66 #8 __libc_start_main in "/lib/tls/i686/cmov/libc.so.6" #9 in "/opt/openfoam210/platforms/linuxGccDPOpt/bin/simpleFoam" 浮点数例外 who can give me some advice?Thanks every reply. 
my fvsolution is:
/** C++ **\  =========    \\ / F ield  OpenFOAM: The Open Source CFD Toolbox   \\ / O peration  Version: 2.1.0   \\ / A nd  Web: www.OpenFOAM.org   \\/ M anipulation   \**/ FoamFile { version 2.0; format ascii; class dictionary; object fvSolution; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // solvers { p { solver GAMG; tolerance 1e7; relTol 0.01; smoother GaussSeidel; nPreSweeps 0; nPostSweeps 2; cacheAgglomeration on; agglomerator faceAreaPair; nCellsInCoarsestLevel 10; mergeLevels 1; } U { solver smoothSolver; smoother GaussSeidel; tolerance 1e8; relTol 0.1; nSweeps 1; } k { solver smoothSolver; smoother GaussSeidel; tolerance 1e8; relTol 0.1; nSweeps 1; } epsilon { solver smoothSolver; smoother GaussSeidel; tolerance 1e8; relTol 0.1; nSweeps 1; } } SIMPLE { nNonOrthogonalCorrectors 3; residualControl { p 1e3; U 1e3; "(kepsilon)" 1e3; } } relaxationFactors { fields { p 0.2; } equations { U 0.7; k 0.7; epsilon 0.7; } } cache { grad(U); } // ************************************************** *********************** // my fvschemes is: /** C++ **\  =========    \\ / F ield  OpenFOAM: The Open Source CFD Toolbox   \\ / O peration  Version: 2.1.0   \\ / A nd  Web: www.OpenFOAM.org   \\/ M anipulation   \**/ FoamFile { version 2.0; format ascii; class dictionary; object fvSchemes; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // ddtSchemes { default steadyState; } gradSchemes { default Gauss linear; grad(p) Gauss linear; grad(U) Gauss linear; } divSchemes { default none; div(phi,U) Gauss upwind grad(U); div((nuEff*dev(T(grad(U))))) Gauss linear; div(phi,epsilon) Gauss upwind; div(phi,k) Gauss upwind; } laplacianSchemes { default Gauss linear limited 0.333; } interpolationSchemes { default linear; } snGradSchemes { default limited 0.333; } fluxRequired { default no; p; } // ************************************************** *********************** // 
Don't know if it may cause the issue, but, as the error says, you're missing the word "uniform" in your U conditions.
I would start by correcting that. 
Thanks for your reply.I think it is just a warning and it should not the reason for my problem.Because i can calculate well in the other case with the warning.

Hi,
if you are sure that your BCs are okay for U (you can check in paraview) I would try to stabilize the first iterations by using a cellLimited grad schemes and setting the relaxation factors for k and eps to 05. or 0.4 Best regards Stawrogin 
Thanks for your reply.I will ues your advice some seconds later.I hope it will works.Thanks again.

which solver for p,u,k,epsilon should i choose?

when i use cellLimited,there gives me the following error:> FOAM FATAL IO ERROR:
Grad scheme not specified Valid grad schemes are : 8 ( Gauss cellLimited cellMDLimited extendedLeastSquares faceLimited faceMDLimited fourth leastSquares ) file: /root/OpenFOAM/root2.1.0/run/tutorials/incompressible/simpleFoam/wf40/system/fvSchemes::gradSchemes::grad(U) at line 26. From function gradScheme<Type>::New(const fvMesh& mesh, Istream& schemeData) in file /home/opencfd/OpenFOAM/OpenFOAM2.1.0/src/finiteVolume/lnInclude/gradScheme.C at line 54. FOAM exiting 
Hi
I would try: gradSchemes { default cellLimited Gauss linear 1; } Stawrogin 
Thanks for your advice.I tryed following your advice,but it failed.can you give me more advice about others?

Hi,
When you used cellLimited Gauss linear 1; what do you mean it failed. Did it fail to even start or did it fail to converge like before? And also, is there a reason for using limited scheme for sngrad and laplacian terms? Kalyan 
it fail to converge like before.i make some changes,and it convergence.But i do not know the output is right or not.when i solve my problem,i will share my experience.

The following is my case files:https://dlweb.dropbox.com/u/69253136/system/fvSchemes
https://dlweb.dropbox.com/u/69253136/system/fvSolution https://dlweb.dropbox.com/u/69253136/0/epsilon https://dlweb.dropbox.com/u/69253136/0/k https://dlweb.dropbox.com/u/69253136/0/nut https://dlweb.dropbox.com/u/69253136/0/p https://dlweb.dropbox.com/u/69253136/0/U The problems I am now facing with are as following:first,when it calculate to the time=353,it occure noconvergence;second,I sample same points's value of velocity,i am sure they are wrong.I only change the files of fvsolution and fvschemes.please give me some advice to correct them. 
Hi,
your breakup is coused by the turbulence model! Code:
bounding k, min: 0 max: 50.8029155486 average: 1.44150802022 But you have a problem with your model: Code:
#6 Foam::incompressible::RASModels::kEpsilon::correct () in "/opt/openfoam210/platforms/linuxGccDPOpt/lib/libincompressibleRASModels.so" I would have a look at that be for trying to change the schemes! I think you `ve got a BCproblem. If you are not sure, save your first time step and have a look at the results. There you should see where your peaks are (k, espilon, p, U ...)  maybe there is a mesh problem at all? I would give you the advice to correct the "uniform" error. Well maybe its not a problem but you should set the files for OF correct. Tobi PS: Solver for k, eps.... PBiCG  have a look at the tutorials pitzDaily 

All times are GMT 4. The time now is 07:39. 