Commit 271d9518 authored by Andrew Heather's avatar Andrew Heather
Browse files

ENH: Added new Curle function object

Calculates the acoustic pressure based on Curle's analogy.

Curle's analogy is implemented as:

    \f[
        p' = 4 \frac{\pi}{c_0}\frac{\vec d}{|\vec d|^2}\frac{d(F)}{d(t)}
    \f]

where
    p'          | Curle's acoustic pressure [Pa] or [Pa (m3/rho)]
    c_0         | Reference speed of sound [m/s]
    \vec d      | Distance vector to observer locations [m]
    F           | Force [N] or [N (m3/rho)]
parent 5741fdae
/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 2017 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
(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/>.
\*---------------------------------------------------------------------------*/
#include "Curle.H"
#include "fvcDdt.H"
#include "mathematicalConstants.H"
#include "addToRunTimeSelectionTable.H"
using namespace Foam::constant;
// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
namespace Foam
{
namespace functionObjects
{
defineTypeNameAndDebug(Curle, 0);
addToRunTimeSelectionTable
(
functionObject,
Curle,
dictionary
);
}
}
// * * * * * * * * * * * * Protected Member Functions * * * * * * * * * * * //
bool Foam::functionObjects::Curle::calc()
{
if (foundObject<volScalarField>(fieldName_))
{
// Evaluate pressure force time derivative
const volScalarField& p = lookupObject<volScalarField>(fieldName_);
const volScalarField dpdt(scopedName("dpdt"), fvc::ddt(p));
const volScalarField::Boundary& dpdtBf = dpdt.boundaryField();
const surfaceVectorField::Boundary& SfBf = mesh_.Sf().boundaryField();
dimensionedVector dfdt
(
"0",
p.dimensions()*dimArea/dimTime,
vector::zero
);
for (auto patchi : patchSet_)
{
dfdt.value() += sum(dpdtBf[patchi]*SfBf[patchi]);
}
reduce(dfdt.value(), sumOp<vector>());
// Construct and store Curle acoustic pressure
const volVectorField& C = mesh_.C();
tmp<volScalarField> tpDash
(
new volScalarField
(
IOobject
(
resultName_,
mesh_.time().timeName(),
mesh_,
IOobject::NO_READ,
IOobject::NO_WRITE
),
mesh_,
dimensionedScalar("0", p.dimensions(), 0)
)
);
volScalarField& pDash = tpDash.ref();
const volVectorField d(scopedName("d"), C - x0_);
pDash = 4*mathematical::pi/c0_*(d/magSqr(d) & dfdt);
return store(resultName_, tpDash);
}
else
{
return false;
}
}
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
Foam::functionObjects::Curle::Curle
(
const word& name,
const Time& runTime,
const dictionary& dict
)
:
fieldExpression(name, runTime, dict, "p"),
patchSet_(),
x0_("x0", dimLength, vector::zero),
c0_("c0", dimVelocity, 0)
{
read(dict);
setResultName(typeName, fieldName_);
}
// * * * * * * * * * * * * * * * * Destructor * * * * * * * * * * * * * * * //
Foam::functionObjects::Curle::~Curle()
{}
// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
bool Foam::functionObjects::Curle::read(const dictionary& dict)
{
if (fieldExpression::read(dict))
{
patchSet_ =
mesh_.boundaryMesh().patchSet(wordReList(dict.lookup("patches")));
if (patchSet_.empty())
{
WarningInFunction
<< "No patches defined"
<< endl;
return false;
}
// Read the reference speed of sound
dict.lookup("c0") >> c0_;
// Set the location of the effective point source to the area-average
// of the patch face centres
const volVectorField::Boundary& Cbf = mesh_.C().boundaryField();
const surfaceScalarField::Boundary& magSfBf =
mesh_.magSf().boundaryField();
x0_.value() = vector::zero;
scalar sumMagSf = 0;
for (auto patchi : patchSet_)
{
x0_.value() += sum(Cbf[patchi]*magSfBf[patchi]);
sumMagSf += sum(magSfBf[patchi]);
}
reduce(x0_.value(), sumOp<vector>());
reduce(sumMagSf, sumOp<scalar>());
x0_.value() /= sumMagSf + ROOTVSMALL;
return true;
}
return false;
}
// ************************************************************************* //
/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 2017 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
(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/>.
Class
Foam::functionObjects::Curle
Group
grpFieldFunctionObjects
Description
Calculates the acoustic pressure based on Curle's analogy.
Curle's analogy is implemented as:
\f[
p' = 4 \frac{\pi}{c_0}\frac{\vec d}{|\vec d|^2}\frac{d(F)}{d(t)}
\f]
where
\vartable
p' | Curle's acoustic pressure [Pa] or [Pa (m3/rho)]
c_0 | Reference speed of sound [m/s]
\vec d | Distance vector to observer locations [m]
F | Force [N] or [N (m3/rho)]
\endvartable
Note
Only the normal-pressure force is included in the force calculation
Usage
Example of function object specification:
\verbatim
Curle1
{
type Curle;
libs ("libfieldFunctionObjects.so");
...
patches (surface1 surface2);
c0 330;
}
\endverbatim
Where the entries comprise:
\table
Property | Description | Required | Default value
type | Type name: Curle | yes |
field | Pressure field name | no | p
result | Acoustic pressure field name | no | Curle
patches | Sound generation patch names | yes |
c0 | Reference speed of sound | yes |
\endtable
See also
- Foam::functionObjects::fieldExpression
- Foam::functionObjects::fvMeshFunctionObject
SourceFiles
Curle.C
\*---------------------------------------------------------------------------*/
#ifndef functionObjects_Curle_H
#define functionObjects_Curle_H
#include "fieldExpression.H"
#include "dimensionedScalar.H"
#include "dimensionedVector.H"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
namespace Foam
{
namespace functionObjects
{
/*---------------------------------------------------------------------------*\
Class Curle Declaration
\*---------------------------------------------------------------------------*/
class Curle
:
public fieldExpression
{
// Private data
// Read from dictionary
//- Patches to integrate forces over
labelHashSet patchSet_;
//- Area-averaged centre of patch faces
dimensionedVector x0_;
//- Reference speed of souund
dimensionedScalar c0_;
// Private Member Functions
//- Disallow default bitwise copy construct
Curle(const Curle&) = delete;
//- Disallow default bitwise assignment
void operator=(const Curle&) = delete;
protected:
//- Calculate the acoustic pressure field and return true if successful
virtual bool calc();
public:
//- Runtime type information
TypeName("Curle");
// Constructors
//- Construct from Time and dictionary
Curle
(
const word& name,
const Time& runTime,
const dictionary& dict
);
//- Destructor
virtual ~Curle();
// Member Functions
//- Read the Curle data
virtual bool read(const dictionary&);
};
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
} // End namespace functionObjects
} // End namespace Foam
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
#endif
// ************************************************************************* //
......@@ -52,6 +52,7 @@ PecletNo/PecletNo.C
blendingFactor/blendingFactor.C
pressure/pressure.C
MachNo/MachNo.C
Curle/Curle.C
fieldsExpression/fieldsExpression.C
add/add.C
......
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