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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
potentialFoam
Description
Potential flow solver which solves for the velocity potential, to
calculate the flux-field, from which the velocity field is obtained by
reconstructing the flux.
This application is particularly useful to generate starting fields for
Navier-Stokes codes.
\*---------------------------------------------------------------------------*/
#include "fvCFD.H"
#include "pisoControl.H"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
int main(int argc, char *argv[])
{
argList::addOption
(
"pName",
"pName",
"Name of the pressure field"
);
argList::addBoolOption
(
"initialiseUBCs",
"Initialise U boundary conditions"
);
argList::addBoolOption
(
"writePhi",
"Write the velocity potential field"
);
argList::addBoolOption
(
"writep",
"Calculate and write the pressure field"
);
argList::addBoolOption
(
"withFunctionObjects",
"execute functionObjects"
);
#include "setRootCase.H"
#include "createTime.H"
#include "createMesh.H"
pisoControl potentialFlow(mesh, "potentialFlow");
#include "createFields.H"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Info<< nl << "Calculating potential flow" << endl;
// Since solver contains no time loop it would never execute
// function objects so do it ourselves
runTime.functionObjects().start();
MRF.makeRelative(phi);
adjustPhi(phi, U, p);
// Non-orthogonal velocity potential corrector loop
while (potentialFlow.correctNonOrthogonal())
{
fvScalarMatrix PhiEqn
(
fvm::laplacian(dimensionedScalar("1", dimless, 1), Phi)
==
fvc::div(phi)
);
PhiEqn.setReference(PhiRefCell, PhiRefValue);
PhiEqn.solve();
if (potentialFlow.finalNonOrthogonalIter())
{
phi -= PhiEqn.flux();
}
}
MRF.makeAbsolute(phi);
Info<< "Continuity error = "
<< mag(fvc::div(phi))().weightedAverage(mesh.V()).value()
<< endl;
U = fvc::reconstruct(phi);
U.correctBoundaryConditions();
Info<< "Interpolated velocity error = "
<< (sqrt(sum(sqr(fvc::flux(U) - phi)))/sum(mesh.magSf())).value()
<< endl;
// Write U and phi
U.write();
phi.write();
// Optionally write Phi
if (args.optionFound("writePhi"))
{
Phi.write();
}
// Calculate the pressure field
if (args.optionFound("writep"))
{
Info<< nl << "Calculating approximate pressure field" << endl;
label pRefCell = 0;
scalar pRefValue = 0.0;
setRefCell
(
p,
potentialFlow.dict(),
pRefCell,
pRefValue
);
// Calculate the flow-direction filter tensor
volScalarField magSqrU(magSqr(U));
volSymmTensorField F(sqr(U)/(magSqrU + SMALL*average(magSqrU)));
// Calculate the divergence of the flow-direction filtered div(U*U)
// Filtering with the flow-direction generates a more reasonable
// pressure distribution in regions of high velocity gradient in the
// direction of the flow
volScalarField divDivUU
(
fvc::div
(
F & fvc::div(phi, U),
"div(div(phi,U))"
)
);
// Solve a Poisson equation for the approximate pressure
while (potentialFlow.correctNonOrthogonal())
{
fvScalarMatrix pEqn
(
fvm::laplacian(p) + divDivUU
);
pEqn.setReference(pRefCell, pRefValue);
pEqn.solve();
}
p.write();
}
runTime.functionObjects().end();
Info<< "ExecutionTime = " << runTime.elapsedCpuTime() << " s"
<< " ClockTime = " << runTime.elapsedClockTime() << " s"
<< nl << endl;
Info<< "End\n" << endl;
return 0;
}
// ************************************************************************* //
|
