[AbhisheK_]

Dear Foam users,

I have developed a code in which I have to stop the simulation after a certain value of an 'objective function' is reached. The code used to work well and suddenly I get a strange error in which the code doesn't stop the process once the convergence criteria is met.

I am unable to figure out what could be reason for this. I have checked the BC's, fvSolution and the code but couldn't figure out. Any suggestions would help.

log file:

Difference from fobjTot prev value is 0.000993049
nCounter: 8
Time = 1007

smoothSolver:  Solving for Ux, Initial residual = 0.000251858, Final residual = 2.41959e-05, No Iterations 2
smoothSolver:  Solving for Uy, Initial residual = 0.000354038, Final residual = 1.28174e-05, No Iterations 3
smoothSolver:  Solving for Uz, Initial residual = 4.22694e-05, Final residual = 1.45835e-06, No Iterations 3
GAMG:  Solving for p, Initial residual = 5.11821e-05, Final residual = 2.93447e-06, No Iterations 2
time step continuity errors : sum local = 0.000686456, global = -0.000113395, cumulative = 313072
DILUPBiCG:  Solving for T, Initial residual = 0.00112086, Final residual = 5.13307e-05, No Iterations 1
ExecutionTime = 61.02 s  ClockTime = 61 s

Difference from fobjTot prev value is 0.000992063
nCounter: 9
Time = 1008

smoothSolver:  Solving for Ux, Initial residual = 0.000250857, Final residual = 2.40985e-05, No Iterations 2
smoothSolver:  Solving for Uy, Initial residual = 0.000352491, Final residual = 1.27625e-05, No Iterations 3
smoothSolver:  Solving for Uz, Initial residual = 4.20958e-05, Final residual = 1.4525e-06, No Iterations 3
GAMG:  Solving for p, Initial residual = 5.10157e-05, Final residual = 2.92618e-06, No Iterations 2
time step continuity errors : sum local = 0.000684548, global = -0.000112994, cumulative = 313072
DILUPBiCG:  Solving for T, Initial residual = 0.00112089, Final residual = 5.13313e-05, No Iterations 1
ExecutionTime = 61.08 s  ClockTime = 61 s

Difference from fobjTot prev value is 0.00099108
nCounter: 10
Time = 1009

smoothSolver:  Solving for Ux, Initial residual = 0.00024986, Final residual = 2.40015e-05, No Iterations 2
smoothSolver:  Solving for Uy, Initial residual = 0.00035095, Final residual = 1.27079e-05, No Iterations 3
smoothSolver:  Solving for Uz, Initial residual = 4.19231e-05, Final residual = 1.44668e-06, No Iterations 3
GAMG:  Solving for p, Initial residual = 5.08501e-05, Final residual = 2.91791e-06, No Iterations 2
time step continuity errors : sum local = 0.000682647, global = -0.000112595, cumulative = 313072
DILUPBiCG:  Solving for T, Initial residual = 0.00112091, Final residual = 5.13319e-05, No Iterations 1
ExecutionTime = 61.15 s  ClockTime = 61 s

reached convergence criterion for fobjTot
Time = 1010

smoothSolver:  Solving for Ux, Initial residual = 0.000248867, Final residual = 2.39049e-05, No Iterations 2
smoothSolver:  Solving for Uy, Initial residual = 0.000349415, Final residual = 1.26535e-05, No Iterations 3
smoothSolver:  Solving for Uz, Initial residual = 4.17513e-05, Final residual = 1.44089e-06, No Iterations 3
GAMG:  Solving for p, Initial residual = 5.06853e-05, Final residual = 2.90968e-06, No Iterations 2
time step continuity errors : sum local = 0.000680751, global = -0.000112198, cumulative = 313072
DILUPBiCG:  Solving for T, Initial residual = 0.00112093, Final residual = 5.13325e-05, No Iterations 1
ExecutionTime = 61.23 s  ClockTime = 61 s

The code should say something like SIMPLE solution converged in 1010 steps but it keeps running. I've attached ControlDict and objective function file for reference. please let me know if you need anymore info.

ControlDict:

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2012                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    location    "system";
    object      controlDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

application     simpleFoam;

startFrom       startTime;

startTime       0;

stopAt          endTime;

endTime         20000;

deltaT          1.0;

writeControl    timeStep;

writeInterval   100;

purgeWrite      0;

writeFormat     ascii;

writePrecision  6;

writeCompression off;

timeFormat      general;

timePrecision   6;

runTimeModifiable true;

libs ("libmyViscosityModels.so");


functions
{
    functionObj
    {
        type            fobj;
        libs            ("libfobjFunctionObject.so");            
        nES             3; //dependent of geometry
        nIS	            1; //dependent of geometry   
    }      
}

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

objective function code: calculates objective function and stops the simulation

if (Pstream::master())
    {
        scalar tol = 1e-3;
        label minCounter = 10;
        label timeSteps = time_.time().value();
        
        scalar fobjTotOld = fobjTot;
        fobjTotOld = Foam::scalar(timeSteps);
        scalar fobjTotNew = fobjTot;
        fobjTotNew = Foam::scalar(timeSteps+1);
        
        scalar diff = (fobjTotNew - fobjTotOld)/fobjTotNew; 


        if (diff <= tol) 
        {
            nCounter_ += 1;
        }
        else
        {
            nCounter_ = 0;
        }

        if (nCounter_ > minCounter) 
        {
            Info << "reached convergence criterion for fobjTot" << endl;
            obr_.time().stopAt(Time::saNoWriteNow);
        }
        else
        {
            Info << "Difference from fobjTot prev value is " << diff << endl; 
            Info << "nCounter: " << nCounter_ << endl; 
        }
    }
    
    return true;
 }