[RodriguezFatz]

Hi all,

I just found something I can't explain.
If I run pimpleFoam in "piso - mode" with nOuterCorrectors = 1, it should basically give the same results / residuals as pisoFoam, right?
But it doesn't. Am I missing something?

PisoFoam - first iteration:

Courant Number mean: 0.10105476 max: 80.232093
DILUPBiCG:  Solving for Ux, Initial residual = 5.1551169e-05, Final residual = 1.3012494e-06, No Iterations 1
DILUPBiCG:  Solving for Uy, Initial residual = 0.00066370866, Final residual = 1.0486425e-05, No Iterations 1
DILUPBiCG:  Solving for Uz, Initial residual = 0.00053294441, Final residual = 1.4905737e-05, No Iterations 1
GAMG:  Solving for p, Initial residual = 0.060534343, Final residual = 0.003730857, No Iterations 1
GAMG:  Solving for p, Initial residual = 0.014627404, Final residual = 0.0013854456, No Iterations 1
time step continuity errors : sum local = 1.5600398e-07, global = 2.2897736e-11, cumulative = 2.2897736e-11
GAMG:  Solving for p, Initial residual = 0.018441401, Final residual = 0.0015585163, No Iterations 1
GAMG:  Solving for p, Initial residual = 0.0052997847, Final residual = 0.00035413287, No Iterations 3
time step continuity errors : sum local = 3.9924023e-08, global = 9.8316871e-10, cumulative = 1.0060664e-09
DILUPBiCG:  Solving for omega, Initial residual = 4.7423151e-09, Final residual = 4.7423151e-09, No Iterations 0
DILUPBiCG:  Solving for k, Initial residual = 0.00021318114, Final residual = 2.2792783e-06, No Iterations 1
bounding k, min: -0.00030976635 max: 1538.8916 average: 203.71795
ExecutionTime = 16.9 s  ClockTime = 17 s

PimpleFoam first iteration:

Courant Number mean: 0.10105476 max: 80.232093
Time = 0.0542865

DILUPBiCG:  Solving for Ux, Initial residual = 9.1161119e-05, Final residual = 5.967053e-07, No Iterations 2
DILUPBiCG:  Solving for Uy, Initial residual = 0.0014069531, Final residual = 8.6561107e-05, No Iterations 1
DILUPBiCG:  Solving for Uz, Initial residual = 0.00098082802, Final residual = 7.8052633e-05, No Iterations 1
GAMG:  Solving for p, Initial residual = 0.1902419, Final residual = 0.011517931, No Iterations 1
GAMG:  Solving for p, Initial residual = 0.037312436, Final residual = 0.0034209833, No Iterations 2
time step continuity errors : sum local = 4.3548365e-07, global = 4.0814203e-09, cumulative = 4.0814203e-09
GAMG:  Solving for p, Initial residual = 0.047153128, Final residual = 0.0024610992, No Iterations 2
GAMG:  Solving for p, Initial residual = 0.014242098, Final residual = 0.0011257833, No Iterations 3
time step continuity errors : sum local = 1.4064563e-07, global = -1.8442513e-08, cumulative = -1.4361093e-08
DILUPBiCG:  Solving for omega, Initial residual = 5.848965e-09, Final residual = 5.848965e-09, No Iterations 0
DILUPBiCG:  Solving for k, Initial residual = 0.00031688108, Final residual = 7.1107399e-06, No Iterations 1
bounding k, min: -0.002219953 max: 1538.8287 average: 204.14907
ExecutionTime = 17.9 s  ClockTime = 18 s

fvSolution file:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.2.1                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
    p
    {
        solver           GAMG;
        tolerance        1e-6;
        relTol           1.0e-1;

        maxIter          100;

        smoother         DICGaussSeidel;

        nPreSweeps       0;
        nPostSweeps      1;
        nFinestSweeps    2;

        cacheAgglomeration true;

        nCellsInCoarsestLevel 50;
        agglomerator     faceAreaPair;
        mergeLevels      1;
    };

    pFinal
{
        solver           GAMG;
        tolerance        1e-6;
        relTol            1.0e-1;

        maxIter          100;

        smoother         DICGaussSeidel;

        nPreSweeps       0;
        nPostSweeps      1;
        nFinestSweeps    2;

        cacheAgglomeration true;

        nCellsInCoarsestLevel 50;
        agglomerator     faceAreaPair;
        mergeLevels      1;
    };

    U
    {
        solver           PBiCG;
        preconditioner   DILU;
        tolerance        1e-08;
        relTol           1.0e-1;
        maxIter          100;
    };

    UFinal
    {
        solver           PBiCG;
        preconditioner   DILU;
        tolerance        1e-08;
        relTol           1.0e-1;
        maxIter          100;
    };
 k   
    {
        solver           PBiCG;
        preconditioner   DILU;
        tolerance        1e-08;
        relTol           1.0e-1;
        maxIter          100;
    };

    kFinal
    {
        solver           PBiCG;
        preconditioner   DILU;
        tolerance        1e-08;
        relTol           1.0e-1;
        maxIter          100;
    };


    omega
    {
        solver           PBiCG;
        preconditioner   DILU;
        tolerance        1e-08;
        relTol           1.0e-1;
        maxIter          100;
    };

    omegaFinal
    {
        solver           PBiCG;
        preconditioner   DILU;
        tolerance        1e-08;
        relTol           1.0e-1;
        maxIter          100;
    };
    
}

SIMPLE
{
        nNonOrthogonalCorrectors 1;
        residualControl
        {
                p               1e-5;
                U               1e-5;
                k               1e-5;
                omega           1e-5;
        }
}

PISO
{       
    nCorrectors    2;
    nNonOrthogonalCorrectors 1;
}



PIMPLE
{
        nOuterCorrectors    1;
        nCorrectors         2;
        nNonOrthogonalCorrectors 1;
//      pRefCell            0;
//      pRefValue           0;
        turbOnFinalIterOnly false;
        residualControl
        {
                p
                {
                        relTol 1.0e-1;
                        tolerance 1.0e-3;

                }
                U
                {
                        relTol 1.0e-1;
                        tolerance 1.0e-3;

                }
                k
                {
                        relTol 1e-1;
                        tolerance 1.0e-3;
                }
                omega
                {
                        relTol 1e-1;
                        tolerance 1.0e-3;
                }

        }
}
                 
potentialFlow
{
    nNonOrthogonalCorrectors 10;
}

/*
relaxationFactors
{
    fields
    {
        "(p)"           0.3;
    }
    equations
    {
        "(U)"           0.7;
        "(k)"           0.8;
        "(omega)"       0.8;
    }
}
*/

// ************************************************************************* //

[RodriguezFatz]

Ok, I don't know what I changed, but now it works...

Edit:
Alright, now I know the problem. For some reason pisoFoam used the relaxationFactors. Obviously it should not so I probably put them at the wrong place.
Now, where and how do I need to put the relaxationFactors in a way that they are just used by pimpleFoam (not the last iteration) and simpleFoam, but not by pisoFoam?