Orifice Plate with a fully developed flow - Problems with convergence

jonmec · June 3, 2011, 19:50

Hy .... i'm trying to simulate the pressure drop caused by the obstruction in a orifice plate. So i generated a duct upstream the obstruction with the purpose of obtaining a fully developed flow before the hole.

However simpleFoam doesn't converge. Please, help me. My term is ending and I still did not achieve satisfactory results.

My turbulence model is kepsilon. CheckMesh is OK. My Re is 10000.

------------------------------------------------------------------------------------------------------------------------------------

Here my fvSchemes

Code:

ddtSchemes
{
    default         steadyState;
}

gradSchemes
{
    default         Gauss linear;
    grad(p)         Gauss linear;
    grad(U)         Gauss linear;
}

divSchemes
{
    default         none;
    div(phi,U)      Gauss upwind;
    div(phi,k)      Gauss upwind;
    div(phi,epsilon) Gauss upwind;
    div(phi,R)      Gauss upwind;
    div(R)          Gauss linear;
    div(phi,nuTilda) Gauss upwind;
    div((nuEff*dev(grad(U).T()))) Gauss linear;
}

laplacianSchemes
{
    default         none;
    laplacian(nuEff,U) Gauss linear corrected;
    laplacian((1|A(U)),p) Gauss linear corrected;
    laplacian(DkEff,k) Gauss linear corrected;
    laplacian(DepsilonEff,epsilon) Gauss linear corrected;
    laplacian(DREff,R) Gauss linear corrected;
    laplacian(DnuTildaEff,nuTilda) Gauss linear corrected;
}

interpolationSchemes
{
    default         linear;
    interpolate(U)  linear;
}

snGradSchemes
{
    default         corrected;
}

fluxRequired
{
    default         no;
    p;
}

------------------------------------------------------------------------------------------------------------------------------------
Now my fvSolution

Code:

solvers
{
    p PCG
    {
        preconditioner   DIC;
        tolerance        1e-06;
        relTol           0.01;
    };
    U PBiCG
    {
        preconditioner   DILU;
        tolerance        1e-05;
        relTol           0.1;
    };
    k PBiCG
    {
        preconditioner   DILU;
        tolerance        1e-05;
        relTol           0.1;
    };
    epsilon PBiCG
    {
        preconditioner   DILU;
        tolerance        1e-05;
        relTol           0.1;
    };
    R PBiCG
    {
        preconditioner   DILU;
        tolerance        1e-05;
        relTol           0.1;
    };
    nuTilda PBiCG
    {
        preconditioner   DILU;
        tolerance        1e-05;
        relTol           0.1;
    };
}


SIMPLE
{
    nNonOrthogonalCorrectors 0;
    pRefCell        0;
    pRefValue       0;
}

relaxationFactors
{
    p               0.3;
    U               0.75;
    k               0.7;
    epsilon         0.7;
    R               0.7;
    nuTilda         0.7;
}

-----------------------------------------------------------------------------------------------------------------------------------
Time 0 for U

Code:

 inlet           
    {
        type            fixedValue;
        value           uniform (0 0 3);
    }

    wall            
    {
        type            fixedValue;
        value           uniform (0 0 0);
    }

   simetria           
    {
        type            symmetryPlane;
    }

    outlet          
    {
        type            zeroGradient;
    }

---------------------------------------------------------------------------------------------------------------------------------------
Time 0 for p

Code:

  inlet           
    {
        type            zeroGradient;
    }

    wall            
    {
        type            zeroGradient;
    }

   simetria           
    {
        type            symmetryPlane;
    }

    outlet          
    {
        type            fixedValue;
        value           uniform 0;
    }

My log file

Code:

Time = 456

DILUPBiCG:  Solving for Ux, Initial residual = 0.000512103, Final residual = 1.48703e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000401474, Final residual = 1.10876e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 4.50922e-05, Final residual = 1.18828e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00228803, Final residual = 2.27407e-05, No Iterations 164
time step continuity errors : sum local = 0.00238667, global = -6.0628e-05, cumulative = -0.127041
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000388629, Final residual = 4.27324e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00396427, Final residual = 3.75563e-05, No Iterations 2
ExecutionTime = 7063.29 s  ClockTime = 7079 s

Time = 457

DILUPBiCG:  Solving for Ux, Initial residual = 0.00050372, Final residual = 1.48732e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000393417, Final residual = 1.0608e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 5.00215e-05, Final residual = 1.27123e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00226589, Final residual = 2.24865e-05, No Iterations 163
time step continuity errors : sum local = 0.00235924, global = -0.000164009, cumulative = -0.127205
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000388612, Final residual = 4.25304e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00397533, Final residual = 3.7655e-05, No Iterations 2
ExecutionTime = 7073.22 s  ClockTime = 7089 s

Time = 458

DILUPBiCG:  Solving for Ux, Initial residual = 0.000504411, Final residual = 1.47415e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000394789, Final residual = 1.04873e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 6.91581e-05, Final residual = 1.54967e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00224121, Final residual = 2.08246e-05, No Iterations 755
time step continuity errors : sum local = 0.00218417, global = 2.1535e-06, cumulative = -0.127203
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000388532, Final residual = 4.2453e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00398655, Final residual = 3.77526e-05, No Iterations 2
ExecutionTime = 7102.86 s  ClockTime = 7119 s

Time = 459

DILUPBiCG:  Solving for Ux, Initial residual = 0.000517339, Final residual = 1.54808e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000410883, Final residual = 1.0981e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 6.09888e-05, Final residual = 1.6352e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00229398, Final residual = 2.18083e-05, No Iterations 179
time step continuity errors : sum local = 0.00229149, global = -5.6239e-05, cumulative = -0.127259
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000389129, Final residual = 4.23547e-06, No Iterations 2
bounding epsilon, min: -0.178234 max: 364036 average: 10221.9
DILUPBiCG:  Solving for k, Initial residual = 0.00399978, Final residual = 3.78724e-05, No Iterations 2
ExecutionTime = 7113.5 s  ClockTime = 7130 s

Time = 460

DILUPBiCG:  Solving for Ux, Initial residual = 0.000483808, Final residual = 1.44835e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000380046, Final residual = 1.13412e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 4.13029e-05, Final residual = 1.19397e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00227407, Final residual = 2.21498e-05, No Iterations 89
time step continuity errors : sum local = 0.00232672, global = 5.68528e-05, cumulative = -0.127202
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000389398, Final residual = 4.23249e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00401211, Final residual = 3.79844e-05, No Iterations 2
ExecutionTime = 7120.94 s  ClockTime = 7137 s

Time = 461

DILUPBiCG:  Solving for Ux, Initial residual = 0.00048556, Final residual = 1.45664e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000381206, Final residual = 1.11524e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 4.07961e-05, Final residual = 1.169e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00225496, Final residual = 2.21822e-05, No Iterations 245
time step continuity errors : sum local = 0.00232942, global = 6.41572e-06, cumulative = -0.127196
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000389578, Final residual = 4.22086e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00402382, Final residual = 3.80896e-05, No Iterations 2
ExecutionTime = 7133.82 s  ClockTime = 7150 s

Time = 462

DILUPBiCG:  Solving for Ux, Initial residual = 0.000498512, Final residual = 1.45726e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000391302, Final residual = 1.0683e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 5.1133e-05, Final residual = 1.2756e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00224598, Final residual = 2.19644e-05, No Iterations 332
time step continuity errors : sum local = 0.00230557, global = -4.69691e-05, cumulative = -0.127242
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000389523, Final residual = 4.20593e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00403516, Final residual = 3.81893e-05, No Iterations 2
ExecutionTime = 7149.37 s  ClockTime = 7165 s

Time = 463

DILUPBiCG:  Solving for Ux, Initial residual = 0.000508548, Final residual = 1.4678e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000398041, Final residual = 1.05333e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 6.0973e-05, Final residual = 1.43804e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00222826, Final residual = 2.12836e-05, No Iterations 99
time step continuity errors : sum local = 0.00223302, global = -0.000169687, cumulative = -0.127412
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000389354, Final residual = 4.18671e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00404604, Final residual = 3.82852e-05, No Iterations 2
ExecutionTime = 7157.2 s  ClockTime = 7173 s

Time = 464

DILUPBiCG:  Solving for Ux, Initial residual = 0.000509481, Final residual = 1.44912e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000397803, Final residual = 1.04437e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 7.94906e-05, Final residual = 1.70902e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.0022065, Final residual = 2.19899e-05, No Iterations 622
time step continuity errors : sum local = 0.0023064, global = 6.12007e-06, cumulative = -0.127406
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000389208, Final residual = 4.17798e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00405747, Final residual = 3.8384e-05, No Iterations 2
ExecutionTime = 7182.9 s  ClockTime = 7199 s

Time = 492

DILUPBiCG:  Solving for Ux, Initial residual = 0.000463906, Final residual = 1.2439e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000364687, Final residual = 9.88269e-06, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 4.63961e-05, Final residual = 1.13945e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00209672, Final residual = 2.01067e-05, No Iterations 753
time step continuity errors : sum local = 0.00211535, global = -1.14803e-06, cumulative = -0.127467
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000393129, Final residual = 3.98323e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00440507, Final residual = 4.15127e-05, No Iterations 2
ExecutionTime = 7625.11 s  ClockTime = 7642 s

Time = 493

DILUPBiCG:  Solving for Ux, Initial residual = 0.000485382, Final residual = 1.26639e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000382994, Final residual = 2.55656e-05, No Iterations 3
DILUPBiCG:  Solving for Uz, Initial residual = 7.7196e-05, Final residual = 1.9067e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00216746, Final residual = 2.16433e-05, No Iterations 24
time step continuity errors : sum local = 0.00228078, global = 5.59411e-05, cumulative = -0.127411
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000393817, Final residual = 3.99394e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00442006, Final residual = 4.1653e-05, No Iterations 2
ExecutionTime = 7630.39 s  ClockTime = 7647 s

Time = 494

DILUPBiCG:  Solving for Ux, Initial residual = 0.000454229, Final residual = 1.35997e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000355828, Final residual = 1.68204e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 4.73086e-05, Final residual = 1.32974e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00214212, Final residual = 2.09423e-05, No Iterations 131
time step continuity errors : sum local = 0.00220641, global = 0.000105288, cumulative = -0.127306
DILUPBiCG:  Solving for epsilon, Initial residual = 0.00039425, Final residual = 3.9975e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00443389, Final residual = 4.17823e-05, No Iterations 2
ExecutionTime = 7638.92 s  ClockTime = 7656 s

Time = 495

DILUPBiCG:  Solving for Ux, Initial residual = 0.000453295, Final residual = 1.3394e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000356429, Final residual = 9.5217e-06, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 3.69828e-05, Final residual = 1.10254e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00212543, Final residual = 2.08334e-05, No Iterations 340
time step continuity errors : sum local = 0.00219434, global = 8.02239e-05, cumulative = -0.127226
DILUPBiCG:  Solving for epsilon, Initial residual = 0.00039448, Final residual = 3.99306e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00444701, Final residual = 4.19023e-05, No Iterations 2
ExecutionTime = 7653.89 s  ClockTime = 7671 s

Time = 496

DILUPBiCG:  Solving for Ux, Initial residual = 0.000470975, Final residual = 1.31057e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000368262, Final residual = 9.95087e-06, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 3.66406e-05, Final residual = 1.02858e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00211582, Final residual = 2.01015e-05, No Iterations 18
time step continuity errors : sum local = 0.00211615, global = 7.15807e-05, cumulative = -0.127154
DILUPBiCG:  Solving for epsilon, Initial residual = 0.0003944, Final residual = 3.98107e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00445943, Final residual = 4.20142e-05, No Iterations 2
ExecutionTime = 7658.79 s  ClockTime = 7676 s

Time = 497

DILUPBiCG:  Solving for Ux, Initial residual = 0.000469239, Final residual = 1.27665e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000365393, Final residual = 1.34082e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 5.0851e-05, Final residual = 1.24694e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00209146, Final residual = 2.08967e-05, No Iterations 154
time step continuity errors : sum local = 0.00219931, global = -5.47e-05, cumulative = -0.127209
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000394246, Final residual = 3.96901e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00447105, Final residual = 4.21189e-05, No Iterations 2
ExecutionTime = 7668.1 s  ClockTime = 7685 s

Time = 498

DILUPBiCG:  Solving for Ux, Initial residual = 0.000474228, Final residual = 1.27292e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000369804, Final residual = 1.17542e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 7.23045e-05, Final residual = 1.57116e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.0020701, Final residual = 2.01235e-05, No Iterations 63
time step continuity errors : sum local = 0.00211732, global = -0.00012504, cumulative = -0.127334
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000393942, Final residual = 3.95612e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00448192, Final residual = 4.22152e-05, No Iterations 2
ExecutionTime = 7674.4 s  ClockTime = 7691 s

Time = 499

DILUPBiCG:  Solving for Ux, Initial residual = 0.00047692, Final residual = 1.27242e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000371529, Final residual = 1.15432e-05, No Iterations 2
DILUPBiCG:  Solving for Uz, Initial residual = 9.53324e-05, Final residual = 1.94679e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00204754, Final residual = 1.80723e-05, No Iterations 730
time step continuity errors : sum local = 0.00190096, global = -2.64022e-07, cumulative = -0.127334
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000393712, Final residual = 3.94621e-06, No Iterations 2
bounding epsilon, min: -0.314136 max: 372313 average: 10397.8
DILUPBiCG:  Solving for k, Initial residual = 0.00449351, Final residual = 4.23151e-05, No Iterations 2
ExecutionTime = 7701.85 s  ClockTime = 7719 s

Time = 500

DILUPBiCG:  Solving for Ux, Initial residual = 0.000511951, Final residual = 1.3066e-05, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.000407941, Final residual = 1.0782e-05, No Iterations 3
DILUPBiCG:  Solving for Uz, Initial residual = 7.41097e-05, Final residual = 1.99966e-06, No Iterations 2
DICPCG:  Solving for p, Initial residual = 0.00213221, Final residual = 2.02643e-05, No Iterations 16
time step continuity errors : sum local = 0.00213662, global = -1.03452e-05, cumulative = -0.127344
DILUPBiCG:  Solving for epsilon, Initial residual = 0.000394417, Final residual = 3.95603e-06, No Iterations 2
DILUPBiCG:  Solving for k, Initial residual = 0.00450856, Final residual = 4.24534e-05, No Iterations 2
ExecutionTime = 7710.26 s  ClockTime = 7727 s

jonmec · June 4, 2011, 10:32

Somedody? Please .... help me =]

calim_cfd · July 27, 2011, 10:55

hi jon! i'm new to foam myself but i think you could try coping the system file from the tutorials folder to your case folder (~/tutorials/incompressible/simpleFoam/airFoil2D/system
) and run it with these settings. Make sure u got the right patches and boundary conditions

you might wanna try setting some monitor points (can't help you much on this) to make sure your results are converging, check your 'stop" criteria too in controlDic

/calim

Balakrshnan Ramakrishnan · July 28, 2011, 06:24

I cannot say from the few lines of your log file, that the solution is not converging..
If you have written out the log file,
you can try using tools like PyFoamPlotWatcher to see how the residuals are.

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June 4, 2011, 10:32		#2
jonmec New Member Jonathas Assunção de Castro Join Date: Mar 2009 Posts: 11 Rep Power: 17	Somedody? Please .... help me =]

July 27, 2011, 10:55		#3
calim_cfd Senior Member mauricio Join Date: Jun 2011 Posts: 172 Rep Power: 18	hi jon! i'm new to foam myself but i think you could try coping the system file from the tutorials folder to your case folder (~/tutorials/incompressible/simpleFoam/airFoil2D/system ) and run it with these settings. Make sure u got the right patches and boundary conditions you might wanna try setting some monitor points (can't help you much on this) to make sure your results are converging, check your 'stop" criteria too in controlDic /calim

July 28, 2011, 06:24		#4
Balakrshnan Ramakrishnan New Member BR Join Date: May 2009 Posts: 23 Rep Power: 17	I cannot say from the few lines of your log file, that the solution is not converging.. If you have written out the log file, you can try using tools like PyFoamPlotWatcher to see how the residuals are.