This repository has been archived on 2023-11-20. You can view files and clone it, but cannot push or open issues or pull requests.
foam-extend4.1-coherent-io/applications/solvers/multiphase/interMixingFoam/threePhaseInterfaceProperties/threePhaseInterfaceProperties.C
2010-09-22 19:13:13 +01:00

209 lines
6.3 KiB
C

/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright held by original author
\\/ 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 2 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, write to the Free Software Foundation,
Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Application
threePhaseInterfaceProperties
Description
Properties to aid interFoam :
1. Correct the alpha boundary condition for dynamic contact angle.
2. Calculate interface curvature.
\*---------------------------------------------------------------------------*/
#include "threePhaseInterfaceProperties.H"
#include "alphaContactAngleFvPatchScalarField.H"
#include "mathematicalConstants.H"
#include "surfaceInterpolate.H"
#include "fvcDiv.H"
#include "fvcGrad.H"
// * * * * * * * * * * * * * * * Static Member Data * * * * * * * * * * * * //
const Foam::scalar Foam::threePhaseInterfaceProperties::convertToRad =
Foam::mathematicalConstant::pi/180.0;
// * * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * //
// Correction for the boundary condition on the unit normal nHat on
// walls to produce the correct contact angle.
// The dynamic contact angle is calculated from the component of the
// velocity on the direction of the interface, parallel to the wall.
void Foam::threePhaseInterfaceProperties::correctContactAngle
(
surfaceVectorField::GeometricBoundaryField& nHatb
) const
{
const volScalarField::GeometricBoundaryField& alpha1 =
mixture_.alpha1().boundaryField();
const volScalarField::GeometricBoundaryField& alpha2 =
mixture_.alpha2().boundaryField();
const volScalarField::GeometricBoundaryField& alpha3 =
mixture_.alpha3().boundaryField();
const volVectorField::GeometricBoundaryField& U =
mixture_.U().boundaryField();
const fvMesh& mesh = mixture_.U().mesh();
const fvBoundaryMesh& boundary = mesh.boundary();
forAll(boundary, patchi)
{
if (isA<alphaContactAngleFvPatchScalarField>(alpha1[patchi]))
{
const alphaContactAngleFvPatchScalarField& a2cap =
refCast<const alphaContactAngleFvPatchScalarField>
(alpha2[patchi]);
const alphaContactAngleFvPatchScalarField& a3cap =
refCast<const alphaContactAngleFvPatchScalarField>
(alpha3[patchi]);
scalarField twoPhaseAlpha2 = max(a2cap, scalar(0));
scalarField twoPhaseAlpha3 = max(a3cap, scalar(0));
scalarField sumTwoPhaseAlpha =
twoPhaseAlpha2 + twoPhaseAlpha3 + SMALL;
twoPhaseAlpha2 /= sumTwoPhaseAlpha;
twoPhaseAlpha3 /= sumTwoPhaseAlpha;
fvsPatchVectorField& nHatp = nHatb[patchi];
scalarField theta =
convertToRad
*(
twoPhaseAlpha2*(180 - a2cap.theta(U[patchi], nHatp))
+ twoPhaseAlpha3*(180 - a3cap.theta(U[patchi], nHatp))
);
vectorField nf = boundary[patchi].nf();
// Reset nHatPatch to correspond to the contact angle
scalarField a12 = nHatp & nf;
scalarField b1 = cos(theta);
scalarField b2(nHatp.size());
forAll(b2, facei)
{
b2[facei] = cos(acos(a12[facei]) - theta[facei]);
}
scalarField det = 1.0 - a12*a12;
scalarField a = (b1 - a12*b2)/det;
scalarField b = (b2 - a12*b1)/det;
nHatp = a*nf + b*nHatp;
nHatp /= (mag(nHatp) + deltaN_.value());
}
}
}
void Foam::threePhaseInterfaceProperties::calculateK()
{
const volScalarField& alpha1 = mixture_.alpha1();
const fvMesh& mesh = alpha1.mesh();
const surfaceVectorField& Sf = mesh.Sf();
// Cell gradient of alpha
volVectorField gradAlpha = fvc::grad(alpha1);
// Interpolated face-gradient of alpha
surfaceVectorField gradAlphaf = fvc::interpolate(gradAlpha);
// Face unit interface normal
surfaceVectorField nHatfv = gradAlphaf/(mag(gradAlphaf) + deltaN_);
correctContactAngle(nHatfv.boundaryField());
// Face unit interface normal flux
nHatf_ = nHatfv & Sf;
// Simple expression for curvature
K_ = -fvc::div(nHatf_);
// Complex expression for curvature.
// Correction is formally zero but numerically non-zero.
//volVectorField nHat = gradAlpha/(mag(gradAlpha) + deltaN_);
//nHat.boundaryField() = nHatfv.boundaryField();
//K_ = -fvc::div(nHatf_) + (nHat & fvc::grad(nHatfv) & nHat);
}
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
Foam::threePhaseInterfaceProperties::threePhaseInterfaceProperties
(
const threePhaseMixture& mixture
)
:
mixture_(mixture),
cAlpha_
(
readScalar
(
mixture.U().mesh().solutionDict().subDict("PISO").lookup("cAlpha")
)
),
sigma12_(mixture.lookup("sigma12")),
sigma13_(mixture.lookup("sigma13")),
deltaN_
(
"deltaN",
1e-8/pow(average(mixture.U().mesh().V()), 1.0/3.0)
),
nHatf_
(
(
fvc::interpolate(fvc::grad(mixture.alpha1()))
/(mag(fvc::interpolate(fvc::grad(mixture.alpha1()))) + deltaN_)
) & mixture.alpha1().mesh().Sf()
),
K_
(
IOobject
(
"K",
mixture.alpha1().time().timeName(),
mixture.alpha1().mesh()
),
-fvc::div(nHatf_)
)
{
calculateK();
}
// ************************************************************************* //