- **OpenFOAM Running, Solving & CFD**
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- - **Buoyancydriven cavity flow**
(*http://www.cfd-online.com/Forums/openfoam-solving/59007-buoyancydriven-cavity-flow.html*)

Hi,
I try to simulate a buoHi,
I try to simulate a buoyancy-driven cavity flow like the example in "Computational Methods for Fluid Dynamics". It is a square with adiabatic walls on the upper and lower side, a hot wall on the right side and a cold wall on left side. I define the temperature hot = 293 K, cold = 253 K and default 273 K. The problem is that after starting the buoyantSimpleFoam solver there is an error. Does somebody has a suggestion where the problem could be? I used the hotRoom-tutorial as basis. I only changed turbulence model to laminar. Also with the k-epsilon modell there is the same problem. Anita Here is the log: Exec : buoyantSimpleFoam . buoyancydriven32 Date : Mar 12 2008 Time : 16:26:08 Host : st31 PID : 25414 Root : /home/kienzani/OpenFOAM/kienzani-1.4.1/run/ownTests/ExamplesBook Case : buoyancydriven32 Nprocs : 1 Create time Create mesh for time = 0 Reading environmentalProperties Reading thermophysical properties Selecting thermodynamics package hThermo<puremixture<consttransport<speciethermo<hc onstthermo<perfectgas>>>>> Reading field U Reading/calculating face flux field phi Creating turbulence model Selecting turbulence model laminar Calculating field g.h Creating field pd Starting time loop Time = 1 DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 9.69948e-07, No Iterations 5 DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 1.36774e-06, No Iterations 5 #0 Foam::error::printStack(Foam:http://www.cfd-online.com/OpenFOAM_D...part/proud.gifstream&) in "/home/kienzani/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so" #1 Foam::sigFpe::sigFpeHandler(int) in "/home/kienzani/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so" #2 Uninterpreted: [0xffffe420] #3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) in "/home/kienzani/OpenFOAM/OpenFOAM-1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so" #4 Foam::tmp<foam::geometricfield<double,> > Foam::operator/<foam::fvspatchfield,>(Foam::GeometricField<double ,> const&, Foam::tmp<foam::geometricfield<double,> > const&) in "/home/kienzani/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linuxGccDPOpt/buoyantSi mpleFoam" #5 main in "/home/kienzani/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linuxGccDPOpt/buoyantSi mpleFoam" #6 __libc_start_main in "/lib/libc.so.6" #7 Foam::regIOobject::readIfModified() in "/home/kienzani/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linuxGccDPOpt/buoyantSi mpleFoam" |

Hi Anita,
I have the same proHi Anita,
I have the same problem, but for my problem is just 3d, and I have some results but I think that it didn't converge...so I had the errors message like : Time = 139 Lookup gradScheme for grad(U) Lookup divScheme for div((muEff*dev2(grad(U).T()))) Lookup laplacianScheme for laplacian(muEff,U) Lookup divScheme for div(phi,U) Lookup gradScheme for grad(rho) Lookup gradScheme for grad(pd) DILUPBiCG: Solving for Ux, Initial residual = 0.249057, Final residual = 1.70173e-06, No Iterations 5 DILUPBiCG: Solving for Uy, Initial residual = 0.0185925, Final residual = 4.28971e-06, No Iterations 4 DILUPBiCG: Solving for Uz, Initial residual = 0.104714, Final residual = 1.6076e-06, No Iterations 5 Lookup interpolationScheme for interpolate(rho) Lookup interpolationScheme for interpolate(p) Lookup interpolationScheme for interpolate(rho) Lookup laplacianScheme for laplacian(alphaEff,h) Lookup divScheme for div(phi,h) DILUPBiCG: Solving for h, Initial residual = 0.00378344, Final residual = 2.23355e-06, No Iterations 3 Lookup interpolationScheme for interpolate((rho*U)) Lookup snGradScheme for snGrad(rho) Lookup interpolationScheme for interpolate(((rho*gh)*(1|A(U)))) Lookup laplacianScheme for laplacian((rho*(1|A(U))),pd) DICPCG: Solving for pd, Initial residual = 0.332361, Final residual = 9.81432e-09, No Iterations 429 Lookup fluxRequired for pd time step continuity errors : sum local = 8.58238e-08, global = -1.04862e-18, cumulative = 3.09173e-18 Lookup gradScheme for grad(rho) Lookup gradScheme for grad(pd) rho max/min : 1.20886 1.20063 ExecutionTime = 11054.2 s ClockTime = 11061 s Anita try to change yr laminar model to turbulence model, but for low Reynolds number, like "LaunderSharmaKE' so for me my questions are : 1- I don't know if I should change the interpolation scheme, and if there is the case which the good scheme for my problem? 2- I know that my problem is the heat transfer, so for the density, I have the boussinesq density in order to create flow between the cold and hot wall, but I dont know where can I find the boussinesq equation fo density. thank you very much for your help. |

Sorry,
but I forgot to sent ySorry,
but I forgot to sent you my fvScheme file : ddtSchemes { default steadyState; } gradSchemes { default Gauss linear; } divSchemes { default none; div(phi,U) Gauss upwind; div(phi,h) Gauss upwind; div(phi,k) Gauss upwind; div(phi,epsilon) Gauss upwind; div(phi,R) Gauss upwind; div(R) Gauss linear; div((muEff*dev2(grad(U).T()))) Gauss linear; } laplacianSchemes { default none; laplacian(muEff,U) Gauss linear corrected; laplacian((rho*(1|A(U))),pd) Gauss linear corrected; laplacian(alphaEff,h) Gauss linear corrected; laplacian(DkEff,k) Gauss linear corrected; laplacian(DepsilonEff,epsilon) Gauss linear corrected; laplacian(DREff,R) Gauss linear corrected; } interpolationSchemes { default linear; } snGradSchemes { default corrected; } fluxRequired { default no; pd; } Thanks for all Best regards |

Hi,
now the solver is workiHi,
now the solver is working correct. I had initialized pressure with zero. After changing to 10000 calculation worked fine. The new problem is that residual of U is falling the first 2500 slowly until below 0.001. Than it rises until 0.1. Afterwards it is nearly constant. Pressure residual does not even fall below 0.01. |

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