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August 4, 2010, 03:51 
Adaptive timestepping

#1 
New Member
Jochem
Join Date: May 2010
Posts: 28
Rep Power: 7 
Hi,
I've read a lot about time stepping on this forum. I've followed the steps from the discussion, ( Adaptive timestepping ) stil there is something going wrong. I want to use this adaptive timestepping in the simpleFoam solver. I've included the 3 files (readTimeControls.H, CourantNo.H and setDeltaT.H) in the solver and 2 files( CourantNo.H and setDeltaT.H ) in the time loop. When I then give the command "wmake", the following error appears : cpp: Internal error: Floating point exception (program cc1) Please submit a full bug report. See <http://gcc.gnu.org/bugs.html> for instructions. make: *** [linux64GccDPOpt/options] Error 1 cpp: Internal error: Floating point exception (program cc1) Please submit a full bug report. See <http://gcc.gnu.org/bugs.html> for instructions. make: *** [linux64GccDPOpt/files] Error 1 wmake error: file 'Make/linux64GccDPOpt/objectFiles' could not be created For clarity I also post the simpleFoam.C file : #include "fvCFD.H" #include "singlePhaseTransportModel.H" #include "RASModel.H" // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // int main(int argc, char *argv[]) { #include "setRootCase.H" #include "createTime.H" #include "createMesh.H" #include "createFields.H" #include "initContinuityErrs.H" #include "readTimeControls.H" #include "CourantNo.H" #include "setDeltaT.H" // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Info<< "\nStarting time loop\n" << endl; while (runTime.run()) { Info<< "Time = " << runTime.timeName() << nl << endl; #include "readSIMPLEControls.H" #include "initConvergenceCheck.H" #include "CourantNo.H" #include "setDeltaT.H" runTime++; p.storePrevIter(); // Pressurevelocity SIMPLE corrector { #include "UEqn.H" #include "pEqn.H" } turbulence>correct(); runTime.write(); Info<< "ExecutionTime = " << runTime.elapsedCpuTime() << " s" << " ClockTime = " << runTime.elapsedClockTime() << " s" << nl << endl; #include "convergenceCheck.H" } Info<< "End\n" << endl; return 0; } Can someone tell my what i am doing wrong? Regards, Jochem 

August 8, 2010, 21:38 

#2 
Senior Member
Alberto Passalacqua
Join Date: Mar 2009
Location: Ames, Iowa, United States
Posts: 1,894
Rep Power: 26 
Simply use pimpleFoam. The simpleFoam solver is for steady state calculations.
Best, 

August 25, 2010, 10:31 
PimpleFoam Solver

#3 
New Member
Jochem
Join Date: May 2010
Posts: 28
Rep Power: 7 
Hi Alberto,
Sorry for the late reaction but i was abroad for 2 weeks. I've been trying to adjust the pimpleFoam tutorial to my case but i've experienced some problems. I've now been able to run a case but the solver doesn't calculate the wind velocity and this is the main purpose of my simulation. I've tried to "include initial conditions" in 0/epsilon and 0/nuTilda but still this does not seems to work. Maybe there is something wrong with my fvSchemes or fvSolution. This files look like this :  fvSchemes ddtSchemes { default Euler; } gradSchemes { default Gauss linear; grad(p) Gauss linear; grad(U) Gauss linear; } divSchemes { default none; div(phi,U) Gauss linearUpwindV Gauss linear;; div(phi,k) Gauss upwind;; div(phi,omega) Gauss upwind; div(phi,epsilon)Gauss limitedLinear 1; div(phi,R) Gauss limitedLinear 1; div(R) Gauss linear; div(phi,nuTilda) Gauss limitedLinear 1; div((nuEff*dev(grad(U).T()))) Gauss linear; } laplacianSchemes { default Gauss linear corrected; } interpolationSchemes { default linear; interpolate(U) linear; } snGradSchemes { default corrected; } fluxRequired { default no; p ; }  fvSolution solvers { p { solver GAMG; tolerance 1e06; relTol 0.01; smoother GaussSeidel; cacheAgglomeration true; nCellsInCoarsestLevel 10; agglomerator faceAreaPair; mergeLevels 1; } pFinal { solver GAMG; tolerance 1e06; relTol 0; smoother GaussSeidel; cacheAgglomeration true; nCellsInCoarsestLevel 10; agglomerator faceAreaPair; mergeLevels 1; } U { solver smoothSolver; smoother GaussSeidel; tolerance 1e8; relTol 0.1; nSweeps 1; } UFinal { solver PBiCG; preconditioner DILU; tolerance 1e05; relTol 0; } k { solver PBiCG; preconditioner DILU; tolerance 1e05; relTol 0; } epsilon { solver PBiCG; preconditioner DILU; tolerance 1e05; relTol 0; } omega { solver PBiCG; preconditioner DILU; tolerance 1e05; relTol 0.1; }; } PIMPLE { nOuterCorrectors 2; nCorrectors 2; nNonOrthogonalCorrectors 0; pRefCell 0; pRefValue 0; } relaxationFactors { U 1; k 1; epsilon 1; } Can u help me solve this problem? Regards, Jochem 

August 25, 2010, 10:40 

#4  
Senior Member
Alberto Passalacqua
Join Date: Mar 2009
Location: Ames, Iowa, United States
Posts: 1,894
Rep Power: 26 
Quote:
Best, 

August 26, 2010, 03:11 

#5 
New Member
Jochem
Join Date: May 2010
Posts: 28
Rep Power: 7 
Hi Alberto,
I am trying to simulate the airflow past the different building of our campus. I have added a triSurface in the constantdirectory, because I am working with an .stl file of our campus. I have used one inlet and one outlet. I've been abled to run the case, but in every timestep I see omega and k changing but Ux,Uy,UZ stays zero. Altough i've included 'initial conditions' in the U file in the 0directory and give an input of 3 m/s in the initial conditions file. Regards, Jochem 

August 26, 2010, 14:40 

#6 
Senior Member
Alberto Passalacqua
Join Date: Mar 2009
Location: Ames, Iowa, United States
Posts: 1,894
Rep Power: 26 
Is the equation for U solved during the iterations?
Do you specify a value of U at the inlet? Or simply patch the initial condition? Best, 

August 27, 2010, 04:08 
Problem solved

#7 
New Member
Jochem
Join Date: May 2010
Posts: 28
Rep Power: 7 
Alberto,
Thanks for the tip. I think I now know what the problem was. Indeed I've patched the "initial conditions" in the Ufile. The problem was that I run the case in parallel. So the case was divided into 6 processors and OpenFoam didn't copy the hole 0directory. The "initial conditions" file wasn't in the 0directory of every processor. I've copied this file and pasted in every processor*/0directory and the problem was solved. Thanks a lot for the help, Regards, Jochem 

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