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/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 2011-2016 OpenFOAM Foundation
\\/ 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/>.
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 "turbulentTransportModel.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"
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 "createMesh.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();
// Update/re-write phi
#include "createPhi.H"
phi.write();
singlePhaseTransportModel laminarTransport(U, phi);
autoPtr<incompressible::turbulenceModel> turbulence
(
incompressible::turbulenceModel::New(U, phi, laminarTransport)
);
if (isA<incompressible::RASModel>(turbulence()))
{
// Calculate nut - reference nut is calculated by the turbulence model
// on its construction
tmp<volScalarField> tnut = turbulence->nut();
volScalarField& nut = tnut.ref();
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
if (args.optionFound("writenut"))
{
Info<< "Writing nut" << endl;
nut.write();
}
//--- Read and modify turbulence fields
// Turbulence k
tmp<volScalarField> tk = turbulence->k();
volScalarField& k = tk.ref();
scalar ck0 = pow025(Cmu)*kappa;
k = (1 - mask)*k + mask*sqr(nut/(ck0*min(y, ybl)));
// do not correct BC - operation may use inconsistent fields wrt these
// local manipulations
// k.correctBoundaryConditions();
Info<< "Writing k\n" << endl;
k.write();
// Turbulence epsilon
tmp<volScalarField> tepsilon = turbulence->epsilon();
volScalarField& epsilon = tepsilon.ref();
scalar ce0 = ::pow(Cmu, 0.75)/kappa;
epsilon = (1 - mask)*epsilon + mask*ce0*k*sqrt(k)/min(y, ybl);
// do not correct BC - wall functions will use non-updated k from
// turbulence model
// 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);
dimensionedScalar k0("VSMALL", k.dimensions(), VSMALL);
omega = (1 - mask)*omega + mask*epsilon/(Cmu*k + k0);
// do not correct BC - wall functions will use non-updated k from
// turbulence model
// 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;
// do not correct BC
// 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;
}
// ************************************************************************* //
|
