/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | www.openfoam.com
\\/ M anipulation |
-------------------------------------------------------------------------------
Copyright (C) 2011-2018 OpenFOAM Foundation
Copyright (C) 2020-2022 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
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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 .
\*---------------------------------------------------------------------------*/
#include "standardPhaseChange.H"
#include "addToRunTimeSelectionTable.H"
#include "thermoSingleLayer.H"
#include "zeroField.H"
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
namespace Foam
{
namespace regionModels
{
namespace surfaceFilmModels
{
// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
defineTypeNameAndDebug(standardPhaseChange, 0);
addToRunTimeSelectionTable
(
phaseChangeModel,
standardPhaseChange,
dictionary
);
// * * * * * * * * * * * * Protected Member Functions * * * * * * * * * * * //
scalar standardPhaseChange::Sh
(
const scalar Re,
const scalar Sc
) const
{
if (Re < 5.0E+05)
{
return 0.664*sqrt(Re)*cbrt(Sc);
}
else
{
return 0.037*pow(Re, 0.8)*cbrt(Sc);
}
}
// * * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * //
standardPhaseChange::standardPhaseChange
(
surfaceFilmRegionModel& film,
const dictionary& dict
)
:
phaseChangeModel(typeName, film, dict),
deltaMin_(coeffDict_.get("deltaMin")),
L_(coeffDict_.get("L")),
TbFactor_(coeffDict_.getOrDefault("TbFactor", 1.1)),
YInfZero_(coeffDict_.getOrDefault("YInfZero", false))
{}
// * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * * //
template
void standardPhaseChange::correctModel
(
const scalar dt,
scalarField& availableMass,
scalarField& dMass,
scalarField& dEnergy,
const YInfType& YInf
)
{
const thermoSingleLayer& film = filmType();
// Set local thermo properties
const SLGThermo& thermo = film.thermo();
const filmThermoModel& filmThermo = film.filmThermo();
const label vapId = thermo.carrierId(filmThermo.name());
// Retrieve fields from film model
const scalarField& delta = film.delta();
const scalarField& pInf = film.pPrimary();
const scalarField& T = film.T();
const scalarField& hs = film.hs();
const scalarField& rho = film.rho();
const scalarField& rhoInf = film.rhoPrimary();
const scalarField& muInf = film.muPrimary();
const scalarField& magSf = film.magSf();
const vectorField dU(film.UPrimary() - film.Us());
const scalarField limMass
(
max(scalar(0), availableMass - deltaMin_*rho*magSf)
);
// Molecular weight of vapour [kg/kmol]
const scalar Wvap = thermo.carrier().W(vapId);
// Molecular weight of liquid [kg/kmol]
const scalar Wliq = filmThermo.W();
forAll(dMass, celli)
{
scalar dm = 0;
if (delta[celli] > deltaMin_)
{
// Cell pressure [Pa]
const scalar pc = pInf[celli];
// Calculate the boiling temperature
const scalar Tb = filmThermo.Tb(pc);
// Local temperature - impose lower limit of 200 K for stability
const scalar Tloc = min(TbFactor_*Tb, max(200.0, T[celli]));
// Saturation pressure [Pa]
const scalar pSat = filmThermo.pv(pc, Tloc);
// Latent heat [J/kg]
const scalar hVap = filmThermo.hl(pc, Tloc);
// Calculate mass transfer
if (pSat >= 0.95*pc)
{
// Boiling
const scalar Cp = filmThermo.Cp(pc, Tloc);
const scalar Tcorr = max(0.0, T[celli] - Tb);
const scalar qCorr = limMass[celli]*Cp*(Tcorr);
dm = qCorr/hVap;
}
else
{
// Primary region density [kg/m3]
const scalar rhoInfc = rhoInf[celli];
// Primary region viscosity [Pa.s]
const scalar muInfc = muInf[celli];
// Reynolds number
const scalar Re = rhoInfc*mag(dU[celli])*L_/muInfc;
// Vapour mass fraction at interface
const scalar Ys = Wliq*pSat/(Wliq*pSat + Wvap*(pc - pSat));
// Vapour diffusivity [m2/s]
const scalar Dab = filmThermo.D(pc, Tloc);
// Schmidt number
const scalar Sc = muInfc/(rhoInfc*(Dab + ROOTVSMALL));
// Sherwood number
const scalar Sh = this->Sh(Re, Sc);
// Mass transfer coefficient [m/s]
const scalar hm = Sh*Dab/(L_ + ROOTVSMALL);
// Add mass contribution to source
dm = dt*magSf[celli]*rhoInfc*hm*(Ys - YInf[celli])/(1.0 - Ys);
}
dMass[celli] += min(limMass[celli], max(dm, 0));
// Heat is assumed to be removed by heat-transfer to the wall
// so the energy remains unchanged by the phase-change.
dEnergy[celli] += dm*hs[celli];
// dEnergy[celli] += dm*(hs[celli] + hVap);
}
}
}
void standardPhaseChange::correctModel
(
const scalar dt,
scalarField& availableMass,
scalarField& dMass,
scalarField& dEnergy
)
{
if (YInfZero_)
{
correctModel(dt, availableMass, dMass, dEnergy, zeroField());
}
else
{
const thermoSingleLayer& film = filmType();
const label vapId = film.thermo().carrierId(film.filmThermo().name());
const scalarField& YInf = film.YPrimary()[vapId];
correctModel(dt, availableMass, dMass, dEnergy, YInf);
}
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
} // End namespace surfaceFilmModels
} // End namespace regionModels
} // End namespace Foam
// ************************************************************************* //