acousticDampingSource.C

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/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
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    \\  /    A nd           | www.openfoam.com
     \\/     M anipulation  |
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    Copyright (C) 2016-2021 OpenCFD Ltd.
-------------------------------------------------------------------------------
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.

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    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
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#include "acousticDampingSource.H"
#include "fvMesh.H"
#include "fvMatrices.H"
#include "fvmSup.H"
#include "addToRunTimeSelectionTable.H"
#include "mathematicalConstants.H"
#include "zeroGradientFvPatchFields.H"

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

namespace Foam
{
namespace fv
{
    defineTypeNameAndDebug(acousticDampingSource, 0);
    addToRunTimeSelectionTable(option, acousticDampingSource, dictionary);
}
}


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

void Foam::fv::acousticDampingSource::setBlendingFactor()
{
    blendFactor_.primitiveFieldRef() = 1;

    const vectorField& Cf = mesh_.C();

    const scalar pi = constant::mathematical::pi;

    forAll(cells_, i)
    {
        label celli = cells_[i];
        scalar d = mag(Cf[celli] - x0_);

        if (d < r1_)
        {
            blendFactor_[celli] = 0.0;
        }
        else if ((d >= r1_) && (d <= r2_))
        {
            blendFactor_[celli] = (1.0 - cos(pi*mag(d - r1_)/(r2_ - r1_)))/2.0;
        }
    }

    blendFactor_.correctBoundaryConditions();
}


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

Foam::fv::acousticDampingSource::acousticDampingSource
(
    const word& name,
    const word& modelType,
    const dictionary& dict,
    const fvMesh& mesh
)
:
    fv::cellSetOption(name, modelType, dict, mesh),
    blendFactor_
    (
        volScalarField
        (
            IOobject
            (
                name_ + ":blend",
                mesh_.time().timeName(),
                mesh_,
                IOobject::NO_READ,
                IOobject::NO_WRITE
            ),
            mesh_,
            dimensionedScalar("blend0", dimless, 1.0),
            zeroGradientFvPatchField<vector>::typeName
        )
    ),
    frequency_("frequency", dimless/dimTime, 0),
    x0_(Zero),
    r1_(0),
    r2_(0),
    URefName_("unknown-URef"),
    w_(20)
{
    read(dict);
}


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

void Foam::fv::acousticDampingSource::addSup
(
    fvMatrix<vector>& eqn,
    const label fieldI
)
{
    const volVectorField& U = eqn.psi();
    const volScalarField coeff(name_ + ":coeff", w_*frequency_*blendFactor_);
    const auto& URef = mesh().lookupObject<volVectorField>(URefName_);

    fvMatrix<vector> dampingEqn
    (
        fvm::Sp(coeff, U) - coeff*URef
    );
    eqn -= dampingEqn;
}


void Foam::fv::acousticDampingSource::addSup
(
    const volScalarField& rho,
    fvMatrix<vector>& eqn,
    const label fieldI
)
{
    const volVectorField& U = eqn.psi();
    const volScalarField coeff(name_ + ":coeff", w_*frequency_*blendFactor_);
    const auto& URef = mesh().lookupObject<volVectorField>(URefName_);

    fvMatrix<vector> dampingEqn
    (
        fvm::Sp(rho*coeff, U) - rho*coeff*URef
    );
    eqn -= dampingEqn;
}


void Foam::fv::acousticDampingSource::addSup
(
    const volScalarField& alpha,
    const volScalarField& rho,
    fvMatrix<vector>& eqn,
    const label fieldI
)
{
    const volVectorField& U = eqn.psi();
    const volScalarField coeff(name_ + ":coeff", w_*frequency_*blendFactor_);
    const auto& URef = mesh().lookupObject<volVectorField>(URefName_);

    fvMatrix<vector> dampingEqn
    (
        fvm::Sp(alpha*rho*coeff, U) - alpha*rho*coeff*URef
    );
    eqn -= dampingEqn;
}


bool Foam::fv::acousticDampingSource::read(const dictionary& dict)
{
    if (fv::cellSetOption::read(dict))
    {
        if (!coeffs_.readIfPresent("UNames", fieldNames_))
        {
            fieldNames_.resize(1);
            fieldNames_.first() = coeffs_.getOrDefault<word>("U", "U");
        }

        fv::option::resetApplied();

        coeffs_.readEntry("frequency", frequency_.value());
        coeffs_.readEntry("URef", URefName_);
        coeffs_.readCompat<vector>("origin", {{"centre", -1806}}, x0_);
        coeffs_.readEntry("radius1", r1_);
        coeffs_.readEntry("radius2", r2_);

        if (coeffs_.readIfPresent("w", w_))
        {
            Info<< name_ << ": Setting stencil width to " << w_ << endl;
        }

        setBlendingFactor();

        return true;
    }

    return false;
}


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