[shereez234]

Here is the transient SIMPLE algorithm implemented in OF 4.0 ( can be used with reasonablyl large courant numbers)

CreateFields.H

Info<< "Reading field p\n" << endl;
volScalarField p
(
    IOobject
    (
        "p",
        runTime.timeName(),
        mesh,
        IOobject::MUST_READ,
        IOobject::AUTO_WRITE
    ),
    mesh
);

Info<< "Reading field U\n" << endl;
volVectorField U
(
    IOobject
    (
        "U",
        runTime.timeName(),
        mesh,
        IOobject::MUST_READ,
        IOobject::AUTO_WRITE
    ),
    mesh
);

#include "createPhi.H"


label pRefCell = 0;
scalar pRefValue = 0.0;
setRefCell(p, piso.dict(), pRefCell, pRefValue);
mesh.setFluxRequired(p.name());


singlePhaseTransportModel laminarTransport(U, phi);

autoPtr<incompressible::turbulenceModel> turbulence
(
    incompressible::turbulenceModel::New(U, phi, laminarTransport)
);

#include "createMRF.H"

transientSimpleFoam.C

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011-2016 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

Application
    transientSIMPLEFOAM

Description
    Large time-step transient solver for incompressible, turbulent flow, using
    the PIMPLE (simple) algorithm.

    Sub-models include:
    - turbulence modelling, i.e. laminar, RAS or LES
    - run-time selectable MRF and finite volume options, e.g. explicit porosity

\*---------------------------------------------------------------------------*/

#include "fvCFD.H"
#include "singlePhaseTransportModel.H"
#include "turbulentTransportModel.H"
#include "pisoControl.H"
#include "fvOptions.H"

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

int main(int argc, char *argv[])
{
    #include "postProcess.H"

    #include "setRootCase.H"
    #include "createTime.H"
    #include "createMesh.H"
    #include "createControl.H"
    #include "createTimeControls.H"
    #include "createFields.H"
    #include "createFvOptions.H"
    #include "initContinuityErrs.H"


    turbulence->validate();

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

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

    while (runTime.run())
    {
        #include "readTimeControls.H"
        #include "CourantNo.H"
        #include "setDeltaT.H"

        runTime++;

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

        // --- Pressure-velocity PIMPLE corrector loop
         while (piso.correct())
        {
            // Solve the Momentum equation U

            tmp<fvVectorMatrix> tUEqn
            (
                fvm::ddt(U) + fvm::div(phi, U)
              + turbulence->divDevReff(U)
            );

            fvVectorMatrix& UEqn = tUEqn.ref();
            UEqn.relax();

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


         //   p.boundaryFieldRef() == p.boundaryField();

            p.boundaryFieldRef().updateCoeffs();

            volScalarField rAU(1.0/UEqn.A());
            U = rAU * UEqn.H();
            tUEqn.clear();
            phi = fvc::interpolate(U) & mesh.Sf();
            adjustPhi(phi, U, p);

            // Store pressure for under-relaxation
            p.storePrevIter();

            tmp<volScalarField> rAtU(rAU);

                while (piso.correctNonOrthogonal())
                {

                    // Pressure corrector
                    fvScalarMatrix pEqn
                    (
                        fvm::laplacian(rAtU(), p) == fvc::div(phi)
                    );

                    pEqn.setReference(pRefCell, pRefValue);

                    pEqn.solve();

                    if (piso.finalNonOrthogonalIter())
                    {
                        phi -= pEqn.flux();
                    }
                }

                #include "continuityErrs.H"

                // Explicitly relax pressure for momentum corrector
                p.relax();

                // Momentum corrector
                U -= rAtU()*fvc::grad(p);
                U.correctBoundaryConditions();
        }

            laminarTransport.correct();
            turbulence->correct();


            runTime.write();

        Info<< "ExecutionTime = " << runTime.elapsedCpuTime() << " s"
            << "  ClockTime = " << runTime.elapsedClockTime() << " s"
            << nl << endl;
      }

    Info<< "End\n" << endl;

    return 0;
 }



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

make/files

transientSimpleFoam.C

EXE = $(FOAM_APPBIN)/transientSimpleFoam

make/options

EXE_INC = \
    -I$(LIB_SRC)/TurbulenceModels/turbulenceModels/lnInclude \
    -I$(LIB_SRC)/TurbulenceModels/incompressible/lnInclude \
    -I$(LIB_SRC)/transportModels \
    -I$(LIB_SRC)/transportModels/incompressible/singlePhaseTransportModel \
    -I$(LIB_SRC)/finiteVolume/lnInclude \
    -I$(LIB_SRC)/meshTools/lnInclude \
    -I$(LIB_SRC)/sampling/lnInclude

EXE_LIBS = \
    -lturbulenceModels \
    -lincompressibleTurbulenceModels \
    -lincompressibleTransportModels \
    -lfiniteVolume \
    -lmeshTools \
    -lfvOptions \
    -lsampling