openfoam/applications/utilities/preProcessing/applyBoundaryLayer/applyBoundaryLayer.C

/*---------------------------------------------------------------------------*\
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  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 1991-2009 OpenCFD Ltd.
     \\/     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
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Application
    applyBoundaryLayer

Description
    Apply a simplified boundary-layer model to the velocity and
    turbulence fields based on the 1/7th power-law.

    The uniform boundary-layer thickness is either provided via the -ybl option
    or calculated as the average of the distance to the wall scaled with
    the thickness coefficient supplied via the option -Cbl.  If both options
    are provided -ybl is used.

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

#include "fvCFD.H"
#include "singlePhaseTransportModel.H"
#include "RASModel.H"
#include "wallDist.H"

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

// turbulence constants - file-scope
static const scalar Cmu(0.09);
static const scalar kappa(0.41);


int main(int argc, char *argv[])
{
    argList::addNote
    (
        "apply a simplified boundary-layer model to the velocity and\n"
        "turbulence fields based on the 1/7th power-law."
    );

    argList::addOption
    (
        "ybl",
        "scalar",
        "specify the boundary-layer thickness"
    );
    argList::addOption
    (
        "Cbl", "scalar",
        "boundary-layer thickness as Cbl * mean distance to wall"
    );
    argList::addBoolOption
    (
        "writenut",
        "write nut field"
    );

    #include "setRootCase.H"
    #include "createTime.H"
    #include "createMesh.H"
    #include "createFields.H"

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

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

    // Modify velocity by applying a 1/7th power law boundary-layer
    // u/U0 = (y/ybl)^(1/7)
    // assumes U0 is the same as the current cell velocity

    scalar yblv = ybl.value();
    forAll(U, celli)
    {
        if (y[celli] <= yblv)
        {
            U[celli] *= ::pow(y[celli]/yblv, (1.0/7.0));
        }
    }

    Info<< "Writing U\n" << endl;
    U.write();

    // Update/re-write phi
    phi = fvc::interpolate(U) & mesh.Sf();
    phi.write();

    // Calculate nut
    tmp<volScalarField> tnut = turbulence->nut();
    volScalarField& nut = tnut();
    volScalarField S = mag(dev(symm(fvc::grad(U))));
    nut = sqr(kappa*min(y, ybl))*::sqrt(2)*S;

    if (args.optionFound("writenut"))
    {
        Info<< "Writing nut" << endl;
        nut.write();
    }

    // Create G field - used by RAS wall functions
    volScalarField G("RASModel::G", nut*2*sqr(S));


    //--- Read and modify turbulence fields

    // Turbulence k
    tmp<volScalarField> tk = turbulence->k();
    volScalarField& k = tk();
    scalar ck0 = pow025(Cmu)*kappa;
    k = sqr(nut/(ck0*min(y, ybl)));
    k.correctBoundaryConditions();

    Info<< "Writing k\n" << endl;
    k.write();


    // Turbulence epsilon
    tmp<volScalarField> tepsilon = turbulence->epsilon();
    volScalarField& epsilon = tepsilon();
    scalar ce0 = ::pow(Cmu, 0.75)/kappa;
    epsilon = ce0*k*sqrt(k)/min(y, ybl);
    epsilon.correctBoundaryConditions();

    Info<< "Writing epsilon\n" << endl;
    epsilon.write();


    // Turbulence omega
    IOobject omegaHeader
    (
        "omega",
        runTime.timeName(),
        mesh,
        IOobject::MUST_READ,
        IOobject::NO_WRITE,
        false
    );

    if (omegaHeader.headerOk())
    {
        volScalarField omega(omegaHeader, mesh);
        omega = epsilon/(Cmu*k);
        omega.correctBoundaryConditions();

        Info<< "Writing omega\n" << endl;
        omega.write();
    }


    // Turbulence nuTilda
    IOobject nuTildaHeader
    (
        "nuTilda",
        runTime.timeName(),
        mesh,
        IOobject::MUST_READ,
        IOobject::NO_WRITE,
        false
    );

    if (nuTildaHeader.headerOk())
    {
        volScalarField nuTilda(nuTildaHeader, mesh);
        nuTilda = nut;
        nuTilda.correctBoundaryConditions();

        Info<< "Writing nuTilda\n" << endl;
        nuTilda.write();
    }


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

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

    return 0;
}


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