CFD Online Discussion Forums - Bug in Artificial Compressibility Method using Dual-Time Stepping

Hello OpenFOAM Community,

I am implementing the Artificial Compressibility method with dual-time stepping. I finished the code by adding a for loop in order to advance the solution in real time besides the pseudo-time stepping that this method uses. Therefore, I had to set also a counter for the real time and do several modifications to the code. I fixed some previous bugs that kept me from having a clean compilation. Once I had a clean compilation, I tried the code and it runs, but it does not print the solution for the specified time-step... Any suggestion of what it can be causing this problem?

Here's the code for more clarity.

Code:

int main(int argc, char *argv[])

{

   

        #include "postProcess.H"

        #include "addCheckCaseOptions.H"

        #include "setRootCaseLists.H"

        #include "createTime.H"

        #include "createMesh.H"

        #include "createControl.H"

        #include "createFields.H"

        #include "initContinuityErrs.H"

        #include "CourantNo.H"

        #include "readTimeControls.H"

        #include "setInitialDeltaT.H"





    scalar maxCoRealTime = runTime.controlDict().lookupOrDefault<scalar>("maxCoRealTime", 1.0);



    scalar realDeltaT = runTime.controlDict().lookupOrDefault<scalar>("realDeltaT", GREAT);

    

    scalar CoNumRealTime = 0.0;



    #include "CourantNoRealTime.H"



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



        Info<< "\nStarting time loop\n" << endl;



    //declaration Time Variables



        auto maxIterRealTime = runTime.controlDict().lookupOrDefault<scalar>("maxIterRealTime",1);

    auto maxIterPseudoTime = runTime.controlDict().lookupOrDefault<scalar>("maxIterPseudoTime",1);

        

    decltype(realDeltaT) timeTotalRealTime = 0.0;

    

    auto runRealTime = runTime.timeIndex();

    runRealTime = 0;



    //declaration of fluid properties



    decltype(U) Udt1 = U;

    decltype(U) Udt0 = U;

    

    

    //Real-time step

    for(auto i = decltype(maxIterRealTime){0}; i < maxIterRealTime; ++i)

    {



        ++runRealTime;

        #include "readRealTimeControls.H"

        #include "CourantNoRealTime.H"

        #include "setRealDeltaT.H"



        Udt0 = Udt1; // Updating U at real time. 



            



        //Pseudo-time step

        while (runTime.timeIndex() < maxIterPseudoTime)

        {



            ++runTime;



            //Time derivative



             auto dualDt = dimensionedScalar("dt_real", dimTime, realDeltaT);

                 Udt1    = U;

                 dt_ddt  = (Udt1 - Udt0) / dualDt;



            //CFL-based time-step



            #include "readTimeControls.H"

            #include "CourantNo.H"

                #include "setDeltaT.H"

                

        

                Info<< "Time = " << runTime.timeName() << nl << endl;

    

                //Continuity Equation



            phi = fvc::interpolate(U) & mesh.Sf();

        

            fvScalarMatrix pEqn

            (

              fvm::ddt(p) + beta * fvc::div(U)

            );



            //pEqn.setReference(pRefCell, pRefValue);



            pEqn.solve();

    

            #include "continuityErrs.H"



            p.correctBoundaryConditions();

    

            //Momentum Equation



                fvVectorMatrix UEqn

            (

              fvm::ddt(U) + fvm::div(phi,U) - fvm::laplacian(nu,U)

            );



            solve(UEqn == -fvc::grad(p) - dt_ddt);



        }

        

        runTime.printExecutionTime(Info);



        

        

        //Update Real time and reset pseudo-time

        

        timeTotalRealTime += realDeltaT;

       

        runTime.setTime(timeTotalRealTime, runRealTime);

            runTime.write();



        runTime.setTime(0.0, 0);

        

    }



    Info<< "End\n" << endl;



    return 0;

}

Thank you