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

416 lines
11 KiB
C

/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 2011-2015 OpenFOAM Foundation
\\/ M anipulation | Copyright (C) 2015 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.
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
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.
Compressible modes is automatically selected based on the existence of the
"thermophysicalProperties" dictionary required to construct the
thermodynamics package.
\*---------------------------------------------------------------------------*/
#include "fvCFD.H"
#include "singlePhaseTransportModel.H"
#include "turbulentTransportModel.H"
#include "turbulentFluidThermoModel.H"
#include "wallDist.H"
#include "processorFvPatchField.H"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
// turbulence constants - file-scope
static const scalar Cmu(0.09);
static const scalar kappa(0.41);
void correctProcessorPatches(volScalarField& vf)
{
if (!Pstream::parRun())
{
return;
}
// Not possible to use correctBoundaryConditions on fields as they may
// use local info as opposed to the constraint values employed here,
// but still need to update processor patches
volScalarField::GeometricBoundaryField& bf = vf.boundaryField();
forAll(bf, patchI)
{
if (isA<processorFvPatchField<scalar> >(bf[patchI]))
{
bf[patchI].initEvaluate();
}
}
forAll(bf, patchI)
{
if (isA<processorFvPatchField<scalar> >(bf[patchI]))
{
bf[patchI].evaluate();
}
}
}
template<class TurbulenceModel>
Foam::tmp<Foam::volScalarField> calcK
(
TurbulenceModel& turbulence,
const volScalarField& mask,
const volScalarField& nut,
const volScalarField& y,
const dimensionedScalar& ybl,
const scalar Cmu,
const scalar kappa
)
{
// Turbulence k
tmp<volScalarField> tk = turbulence->k();
volScalarField& k = tk();
scalar ck0 = pow025(Cmu)*kappa;
k = (1 - mask)*k + mask*sqr(nut/(ck0*min(y, ybl)));
k.rename("k");
// Do not correct BC
// - operation may use inconsistent fields wrt these local manipulations
//k.correctBoundaryConditions();
correctProcessorPatches(k);
Info<< "Writing k\n" << endl;
k.write();
return tk;
}
template<class TurbulenceModel>
Foam::tmp<Foam::volScalarField> calcEpsilon
(
TurbulenceModel& turbulence,
const volScalarField& mask,
const volScalarField& k,
const volScalarField& y,
const dimensionedScalar& ybl,
const scalar Cmu,
const scalar kappa
)
{
// Turbulence epsilon
tmp<volScalarField> tepsilon = turbulence->epsilon();
volScalarField& epsilon = tepsilon();
scalar ce0 = ::pow(Cmu, 0.75)/kappa;
epsilon = (1 - mask)*epsilon + mask*ce0*k*sqrt(k)/min(y, ybl);
epsilon.max(SMALL);
epsilon.rename("epsilon");
// Do not correct BC
// - operation may use inconsistent fields wrt these local manipulations
// epsilon.correctBoundaryConditions();
correctProcessorPatches(epsilon);
Info<< "Writing epsilon\n" << endl;
epsilon.write();
return tepsilon;
}
void calcOmega
(
const fvMesh& mesh,
const volScalarField& mask,
const volScalarField& k,
const volScalarField& epsilon
)
{
// Turbulence omega
IOobject omegaHeader
(
"omega",
mesh.time().timeName(),
mesh,
IOobject::MUST_READ,
IOobject::NO_WRITE,
false
);
if (omegaHeader.headerOk())
{
volScalarField omega(omegaHeader, mesh);
dimensionedScalar k0("SMALL", k.dimensions(), SMALL);
omega = (1 - mask)*omega + mask*epsilon/(Cmu*k + k0);
omega.max(SMALL);
// Do not correct BC
// - operation may use inconsistent fields wrt these local
// manipulations
// omega.correctBoundaryConditions();
correctProcessorPatches(omega);
Info<< "Writing omega\n" << endl;
omega.write();
}
}
void setField
(
const fvMesh& mesh,
const word& fieldName,
const volScalarField& value
)
{
IOobject fldHeader
(
fieldName,
mesh.time().timeName(),
mesh,
IOobject::MUST_READ,
IOobject::NO_WRITE,
false
);
if (fldHeader.headerOk())
{
volScalarField fld(fldHeader, mesh);
fld = value;
// Do not correct BC
// - operation may use inconsistent fields wrt these local
// manipulations
// fld.correctBoundaryConditions();
correctProcessorPatches(fld);
Info<< "Writing " << fieldName << nl << endl;
fld.write();
}
}
void calcCompressible
(
const fvMesh& mesh,
const volScalarField& mask,
const volVectorField& U,
const volScalarField& y,
const dimensionedScalar& ybl
)
{
const Time& runTime = mesh.time();
autoPtr<fluidThermo> pThermo(fluidThermo::New(mesh));
fluidThermo& thermo = pThermo();
volScalarField rho(thermo.rho());
// Update/re-write phi
#include "compressibleCreatePhi.H"
phi.write();
autoPtr<compressible::turbulenceModel> turbulence
(
compressible::turbulenceModel::New
(
rho,
U,
phi,
thermo
)
);
// Calculate nut - reference nut is calculated by the turbulence model
// on its construction
tmp<volScalarField> tnut = turbulence->nut();
volScalarField& nut = tnut();
volScalarField S(mag(dev(symm(fvc::grad(U)))));
nut = (1 - mask)*nut + mask*sqr(kappa*min(y, ybl))*::sqrt(2)*S;
// Do not correct BC - wall functions will 'undo' manipulation above
// by using nut from turbulence model
correctProcessorPatches(nut);
nut.write();
tmp<volScalarField> k =
calcK(turbulence, mask, nut, y, ybl, Cmu, kappa);
tmp<volScalarField> epsilon =
calcEpsilon(turbulence, mask, k, y, ybl, Cmu, kappa);
calcOmega(mesh, mask, k, epsilon);
setField(mesh, "nuTilda", nut);
}
void calcIncompressible
(
const fvMesh& mesh,
const volScalarField& mask,
const volVectorField& U,
const volScalarField& y,
const dimensionedScalar& ybl
)
{
const Time& runTime = mesh.time();
// Update/re-write phi
#include "createPhi.H"
phi.write();
singlePhaseTransportModel laminarTransport(U, phi);
autoPtr<incompressible::turbulenceModel> turbulence
(
incompressible::turbulenceModel::New(U, phi, laminarTransport)
);
tmp<volScalarField> tnut = turbulence->nut();
// Calculate nut - reference nut is calculated by the turbulence model
// on its construction
volScalarField& nut = tnut();
volScalarField S(mag(dev(symm(fvc::grad(U)))));
nut = (1 - mask)*nut + mask*sqr(kappa*min(y, ybl))*::sqrt(2)*S;
// Do not correct BC - wall functions will 'undo' manipulation above
// by using nut from turbulence model
correctProcessorPatches(nut);
nut.write();
tmp<volScalarField> k =
calcK(turbulence, mask, nut, y, ybl, Cmu, kappa);
tmp<volScalarField> epsilon =
calcEpsilon(turbulence, mask, k, y, ybl, Cmu, kappa);
calcOmega(mesh, mask, k, epsilon);
setField(mesh, "nuTilda", nut);
}
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."
);
#include "addRegionOption.H"
argList::addOption
(
"ybl",
"scalar",
"specify the boundary-layer thickness"
);
argList::addOption
(
"Cbl",
"scalar",
"boundary-layer thickness as Cbl * mean distance to wall"
);
#include "setRootCase.H"
if (!args.optionFound("ybl") && !args.optionFound("Cbl"))
{
FatalErrorInFunction
<< "Neither option 'ybl' or 'Cbl' have been provided to calculate "
<< "the boundary-layer thickness.\n"
<< "Please choose either 'ybl' OR 'Cbl'."
<< exit(FatalError);
}
else if (args.optionFound("ybl") && args.optionFound("Cbl"))
{
FatalErrorInFunction
<< "Both 'ybl' and 'Cbl' have been provided to calculate "
<< "the boundary-layer thickness.\n"
<< "Please choose either 'ybl' OR 'Cbl'."
<< exit(FatalError);
}
#include "createTime.H"
#include "createNamedMesh.H"
#include "createFields.H"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
// 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
Info<< "Setting boundary layer velocity" << nl << endl;
scalar yblv = ybl.value();
forAll(U, cellI)
{
if (y[cellI] <= yblv)
{
mask[cellI] = 1;
U[cellI] *= ::pow(y[cellI]/yblv, (1.0/7.0));
}
}
mask.correctBoundaryConditions();
Info<< "Writing U\n" << endl;
U.write();
if
(
IOobject
(
basicThermo::dictName,
runTime.constant(),
mesh
).headerOk()
)
{
calcCompressible(mesh, mask, U, y, ybl);
}
else
{
calcIncompressible(mesh, mask, U, y, ybl);
}
Info<< nl << "ExecutionTime = " << runTime.elapsedCpuTime() << " s"
<< " ClockTime = " << runTime.elapsedClockTime() << " s"
<< nl << endl;
Info<< "End\n" << endl;
return 0;
}
// ************************************************************************* //