objectiveMoment.C

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    Copyright (C) 2013-2019, 2022 FOSS GP
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#include "objectiveMoment.H"
#include "createZeroField.H"
#include "wallFvPatch.H"
#include "addToRunTimeSelectionTable.H"

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

namespace Foam
{

namespace objectives
{

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

defineTypeNameAndDebug(objectiveMoment, 0);
addToRunTimeSelectionTable
(
    objectiveIncompressible,
    objectiveMoment,
    dictionary
);


// * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //

objectiveMoment::objectiveMoment
(
    const fvMesh& mesh,
    const dictionary& dict,
    const word& adjointSolverName,
    const word& primalSolverName
)
:
    objectiveIncompressible(mesh, dict, adjointSolverName, primalSolverName),
    momentPatches_
    (
        mesh_.boundaryMesh().patchSet
        (
            dict.get<wordRes>("patches")
        ).sortedToc()
    ),
    momentDirection_(dict.get<vector>("direction")),
    rotationCentre_(dict.get<vector>("rotationCenter")),
    Aref_(dict.get<scalar>("Aref")),
    lRef_(dict.get<scalar>("lRef")),
    rhoInf_(dict.get<scalar>("rhoInf")),
    UInf_(dict.get<scalar>("UInf")),
    invDenom_(2./(rhoInf_*UInf_*UInf_*Aref_*lRef_)),
    devReff_(vars_.turbulence()->devReff()())
{
    // Sanity check and print info
    if (momentPatches_.empty())
    {
        FatalErrorInFunction
            << "No valid patch name on which to minimize " << type() << endl
            << exit(FatalError);
    }
    if (debug)
    {
        Info<< "Minimizing " << type() << " in patches:" << endl;
        for (const label patchI : momentPatches_)
        {
            Info<< "\t " << mesh_.boundary()[patchI].name() << endl;
        }
    }

    // Allocate boundary field pointers
    bdJdpPtr_.reset(createZeroBoundaryPtr<vector>(mesh_));
    bdSdbMultPtr_.reset(createZeroBoundaryPtr<vector>(mesh_));
    bdxdbMultPtr_.reset(createZeroBoundaryPtr<vector>(mesh_));
    bdxdbDirectMultPtr_.reset(createZeroBoundaryPtr<vector>(mesh_));
    bdJdnutPtr_.reset(createZeroBoundaryPtr<scalar>(mesh_));
  //bdJdGradUPtr_.reset(createZeroBoundaryPtr<tensor>(mesh_));
}


// * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //

scalar objectiveMoment::J()
{
    vector pressureMoment(Zero);
    vector viscousMoment(Zero);
    vector cumulativeMoment(Zero);

    // Update field here and use the same value for all functions
    const volScalarField& p = vars_.pInst();
    devReff_ = vars_.turbulence()->devReff()();

    for (const label patchI : momentPatches_)
    {
        const fvPatch& patch = mesh_.boundary()[patchI];
        const vectorField& Sf = patch.Sf();
        vectorField dx(patch.Cf() - rotationCentre_);
        pressureMoment += gSum
        (
            rhoInf_*(dx ^ Sf)*p.boundaryField()[patchI]
        );

        // Viscous term calculated using the full tensor derivative
        viscousMoment += gSum
        (
            rhoInf_*(dx^(devReff_.boundaryField()[patchI] & Sf))
        );
    }

    cumulativeMoment = pressureMoment + viscousMoment;

    scalar moment = cumulativeMoment & momentDirection_;
    scalar Cm = moment*invDenom_;
    DebugInfo<<
        "Moment|Coeff " << moment << "|" << Cm << endl;
    J_ = Cm;
    return Cm;
}


void objectiveMoment::update_meanValues()
{
    if (computeMeanFields_)
    {
        const volVectorField& U = vars_.U();
        const autoPtr<incompressible::RASModelVariables>& turbVars =
            vars_.RASModelVariables();
        const singlePhaseTransportModel& lamTransp = vars_.laminarTransport();

        devReff_ = turbVars->devReff(lamTransp, U)();
    }
}


void objectiveMoment::update_boundarydJdp()
{
    for (const label patchI : momentPatches_)
    {
        const fvPatch& patch = mesh_.boundary()[patchI];
        tmp<vectorField> tdx = patch.Cf() - rotationCentre_;
        bdJdpPtr_()[patchI] = (momentDirection_ ^ tdx)*invDenom_*rhoInf_;
    }
}


void objectiveMoment::update_dSdbMultiplier()
{
    const volScalarField& p = vars_.p();

    for (const label patchI : momentPatches_)
    {
        const fvPatch& patch = mesh_.boundary()[patchI];
        tmp<vectorField> tdx = patch.Cf() - rotationCentre_;
        bdSdbMultPtr_()[patchI] =
            (
                (
                    rhoInf_*
                    (
                        (momentDirection_ ^ tdx()) &
                        (
                            devReff_.boundaryField()[patchI]
                        )
                    )
                )
              + rhoInf_*(momentDirection_ ^ tdx())*p.boundaryField()[patchI]
            )
           *invDenom_;
    }
}


void objectiveMoment::update_dxdbMultiplier()
{
    const volScalarField& p = vars_.p();
    const volVectorField& U = vars_.U();

    const autoPtr<incompressible::RASModelVariables>& turbVars =
        vars_.RASModelVariables();
    const singlePhaseTransportModel& lamTransp = vars_.laminarTransport();

    // We only need to modify the boundaryField of gradU locally.
    // If grad(U) is cached then
    // a. The .ref() call fails since the tmp is initialised from a
    //    const ref
    // b. we would be changing grad(U) for all other places in the code
    //    that need it
    // So, always allocate new memory and avoid registering the new field
    tmp<volTensorField> tgradU =
        volTensorField::New("gradULocal", fvc::grad(U));
    volTensorField::Boundary& gradUbf = tgradU.ref().boundaryFieldRef();

    // Explicitly correct the boundary gradient to get rid of the
    // tangential component
    forAll(mesh_.boundary(), patchI)
    {
        const fvPatch& patch = mesh_.boundary()[patchI];
        if (isA<wallFvPatch>(patch))
        {
            tmp<vectorField> tnf = mesh_.boundary()[patchI].nf();
            gradUbf[patchI] = tnf*U.boundaryField()[patchI].snGrad();
        }
    }

    // Term coming from gradp
    tmp<volVectorField> tgradp = fvc::grad(p);
    const volVectorField& gradp = tgradp.cref();
    for (const label patchI : momentPatches_)
    {
        const fvPatch& patch = mesh_.boundary()[patchI];
        tmp<vectorField> tnf = patch.nf();
        tmp<vectorField> tdx = patch.Cf() - rotationCentre_;
        bdxdbMultPtr_()[patchI] =
            (momentDirection_ & (tdx ^ tnf))*gradp.boundaryField()[patchI]
           *invDenom_*rhoInf_;
    }
    tgradp.clear();

    // Term coming from stresses
    tmp<volScalarField> tnuEff = lamTransp.nu() + turbVars->nut();
    tmp<volSymmTensorField> tstress = tnuEff*twoSymm(tgradU);
    const volSymmTensorField& stress = tstress.cref();
    autoPtr<volVectorField> ptemp
        (Foam::createZeroFieldPtr<vector>( mesh_, "temp", sqr(dimVelocity)));
    volVectorField& temp = ptemp.ref();

    for (label idir = 0; idir < pTraits<vector>::nComponents; ++idir)
    {
        unzipRow(stress, idir, temp);
        volTensorField gradStressDir(fvc::grad(temp));
        for (const label patchI : momentPatches_)
        {
            const fvPatch& patch = mesh_.boundary()[patchI];
            tmp<vectorField> tnf = patch.nf();
            tmp<vectorField> tdx = patch.Cf() - rotationCentre_;
            tmp<scalarField> taux = (momentDirection_ ^ tdx)().component(idir);
            bdxdbMultPtr_()[patchI] -=
                taux*(gradStressDir.boundaryField()[patchI] & tnf)
               *invDenom_*rhoInf_;
        }
    }
}


void objectiveMoment::update_dxdbDirectMultiplier()
{
    const volScalarField& p = vars_.p();

    for (const label patchI : momentPatches_)
    {
        const fvPatch& patch = mesh_.boundary()[patchI];
        tmp<vectorField> tnf = patch.nf();
        const vectorField& nf = tnf();
        const vectorField dx(patch.Cf() - rotationCentre_);
        const vectorField force
        (
            rhoInf_
           *(
                ((p.boundaryField()[patchI]*nf)
              + (devReff_.boundaryField()[patchI] & nf))
            )
        );
        bdxdbDirectMultPtr_()[patchI] =
            (force^momentDirection_)*invDenom_*rhoInf_;
    }
}


void objectiveMoment::update_boundarydJdnut()
{
    const volVectorField& U = vars_.U();
    volSymmTensorField devGradU(devTwoSymm(fvc::grad(U)));

    for (const label patchI : momentPatches_)
    {
        const fvPatch& patch = mesh_.boundary()[patchI];
        tmp<vectorField> tnf = patch.nf();
        tmp<vectorField> tdx = patch.Cf() - rotationCentre_;
        const fvPatchSymmTensorField& bdevGradU =
            devGradU.boundaryField()[patchI];
        bdJdnutPtr_()[patchI] =
          - rhoInf_*((tdx ^ (bdevGradU & tnf)) & momentDirection_)*invDenom_;
    }
}


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

} // End namespace objectives
} // End namespace Foam

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