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LBC.hpp
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// -*- mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
// vi: set et ts=4 sw=4 sts=4:
/*
Copyright 2022 NORCE.
This file is part of the Open Porous Media project (OPM).
OPM 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.
OPM 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 OPM. If not, see <http://www.gnu.org/licenses/>.
Consult the COPYING file in the top-level source directory of this
module for the precise wording of the license and the list of
copyright holders.
*/
#ifndef LBC_HPP
#define LBC_HPP
#include <cmath>
#include <vector>
namespace Opm
{
template <class Scalar, class FluidSystem>
class ViscosityModels
{
public:
// Standard LBC model. (Lohrenz, Bray & Clark: "Calculating Viscosities of Reservoir
// fluids from Their Compositions", JPT 16.10 (1964).
template <class FluidState, class Params, class LhsEval = typename FluidState::Scalar>
static LhsEval LBC(const FluidState& fluidState,
const Params& /*paramCache*/,
unsigned phaseIdx)
{
const Scalar MPa_atm = 0.101325;
const Scalar R = Opm::Constants<Scalar>::R;
const auto& T = Opm::decay<LhsEval>(fluidState.temperature(phaseIdx));
const auto& P = Opm::decay<LhsEval>(fluidState.pressure(phaseIdx));
const auto& Z = Opm::decay<LhsEval>(fluidState.compressFactor(phaseIdx));
LhsEval sumVolume = 0.0;
for (unsigned compIdx = 0; compIdx < FluidSystem::numComponents; ++compIdx) {
const auto& x = Opm::decay<LhsEval>(fluidState.moleFraction(phaseIdx, compIdx));
const Scalar v_c = FluidSystem::criticalVolume(compIdx) / 1000; // converting to m3/mol from m3/kmol
sumVolume += x*v_c;
}
LhsEval rho_pc = 1.0 / sumVolume;
LhsEval V = (R * T * Z)/P;
LhsEval rho = 1.0 / V;
LhsEval rho_r = rho / rho_pc;
LhsEval xsum_T_c = 0.0; // mixture pseudocritical temperature
LhsEval xsum_Mm = 0.0; // mixture molar mass
LhsEval xsum_p_ca = 0.0; // mixture pseudocritical pressure
for (unsigned compIdx = 0; compIdx < FluidSystem::numComponents; ++compIdx) {
const Scalar& p_c = FluidSystem::criticalPressure(compIdx) / 1e6; // converting to Mpa from pascal
const Scalar& T_c = FluidSystem::criticalTemperature(compIdx);
const Scalar Mm = FluidSystem::molarMass(compIdx) * 1000; // converting to kg/kmol from kg/mol;
const auto& x = Opm::decay<LhsEval>(fluidState.moleFraction(phaseIdx, compIdx));
Scalar p_ca = p_c / MPa_atm;
xsum_T_c += x * T_c;
xsum_Mm += x * Mm;
xsum_p_ca += x * p_ca;
}
LhsEval zeta_tot = Opm::pow(xsum_T_c / (Opm::pow(xsum_Mm,3.0) * Opm::pow(xsum_p_ca,4.0)),1./6);
LhsEval my0 = 0.0;
LhsEval sumxrM = 0.0;
for (unsigned compIdx = 0; compIdx < FluidSystem::numComponents; ++compIdx) {
const Scalar& p_c = FluidSystem::criticalPressure(compIdx) / 1e6; // converting to Mpa from pa;
const Scalar& T_c = FluidSystem::criticalTemperature(compIdx);
const Scalar Mm = FluidSystem::molarMass(compIdx) * 1000; // converting to kg/kmol from kg/mol;
const auto& x = Opm::decay<LhsEval>(fluidState.moleFraction(phaseIdx, compIdx));
Scalar p_ca = p_c / MPa_atm;
Scalar zeta = std::pow(T_c / (std::pow(Mm,3.0) * std::pow(p_ca,4.0)),1./6);
LhsEval T_r = T/T_c;
LhsEval xrM = x * std::pow(Mm,0.5);
LhsEval mys = 0.0;
if (T_r <= 1.5) {
mys = 34.0e-5*Opm::pow(T_r,0.94)/zeta;
} else {
mys = 17.78e-5*Opm::pow(4.58*T_r - 1.67, 0.625)/zeta;
}
my0 += xrM*mys;
sumxrM += xrM;
}
my0 /= sumxrM;
std::vector<Scalar> LBC = {0.10230,
0.023364,
0.058533,
-0.040758, // typo in 1964-paper: -0.40758
0.0093324};
LhsEval sumLBC = 0.0;
for (int i = 0; i < 5; ++i) {
sumLBC += Opm::pow(rho_r,i)*LBC[i];
}
return (my0 + (Opm::pow(sumLBC,4.0) - 1e-4)/zeta_tot)/1e3; // mPas-> Pas
}
};
} // namespace Opm
#endif // LBC_HPP
Opm::Constants::R
static constexpr Scalar R
The ideal gas constant [J/(mol K)].
Definition Constants.hpp:45
Opm::ViscosityModels
Definition LBC.hpp:40
Opm
This class implements a small container which holds the transmissibility mulitpliers for all the face...
Definition Exceptions.hpp:30