Brine.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:
/*
  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 OPM_BRINE_HPP
#define OPM_BRINE_HPP
 
#include <opm/material/components/Component.hpp>
#include <opm/material/common/MathToolbox.hpp>
 
namespace Opm {
 
template <class Scalar, class H2O>
class Brine : public Component<Scalar, Brine<Scalar, H2O> >
{
public:
    static Scalar salinity;
 
    static const char* name()
    { return "Brine"; }
 
    static bool gasIsIdeal()
    { return H2O::gasIsIdeal(); }
 
    static bool gasIsCompressible()
    { return H2O::gasIsCompressible(); }
 
    static bool liquidIsCompressible()
    { return H2O::liquidIsCompressible(); }
 
    static Scalar molarMass()
    {
        const Scalar M1 = H2O::molarMass();
        constexpr Scalar M2 = 58e-3; // molar mass of NaCl [kg/mol]
        const Scalar X2 = salinity; // mass fraction of salt in brine
        return M1*M2/(M2 + X2*(M1 - M2));
    }
 
    static Scalar criticalTemperature()
    { return H2O::criticalTemperature(); /* [K] */ }
 
    static Scalar criticalPressure()
    { return H2O::criticalPressure(); /* [N/m^2] */ }
 
    static Scalar criticalVolume()
    { return H2O::criticalVolume(); /* [m3/kmol] */ }
 
    static Scalar acentricFactor()
    { return H2O::acentricFactor(); }
 
    static Scalar tripleTemperature()
    { return H2O::tripleTemperature(); /* [K] */ }
 
    static Scalar triplePressure()
    { return H2O::triplePressure(); /* [N/m^2] */ }
 
    template <class Evaluation>
    static Evaluation vaporPressure(const Evaluation& T)
    { return H2O::vaporPressure(T); /* [N/m^2] */ }
 
    template <class Evaluation>
    static Evaluation gasEnthalpy(const Evaluation& temperature,
                                  const Evaluation& pressure)
    { return H2O::gasEnthalpy(temperature, pressure); /* [J/kg] */ }
 
    template <class Evaluation>
    static Evaluation liquidEnthalpy(const Evaluation& temperature,
                                     const Evaluation& pressure)
    {
        // Numerical coefficents from Palliser and McKibbin
        static constexpr Scalar f[] = {
            2.63500e-1, 7.48368e-6, 1.44611e-6, -3.80860e-10
        };
 
        // Numerical coefficents from Michaelides for the enthalpy of brine
        static constexpr Scalar a[4][3] = {
            { -9633.6, -4080.0, +286.49 },
            { +166.58, +68.577, -4.6856 },
            { -0.90963, -0.36524, +0.249667e-1 },
            { +0.17965e-2, +0.71924e-3, -0.4900e-4 }
        };
 
        const Evaluation theta = temperature - 273.15;
 
        Evaluation S = salinity;
        const Evaluation S_lSAT =
            f[0]
            + f[1]*theta
            + f[2]*pow(theta, 2)
            + f[3]*pow(theta, 3);
 
        // Regularization
        if (S > S_lSAT)
            S = S_lSAT;
 
        const Evaluation hw = H2O::liquidEnthalpy(temperature, pressure)/1e3; // [kJ/kg]
 
        // From Daubert and Danner
        const Evaluation h_NaCl =
            (3.6710e4*temperature
             + (6.2770e1/2)*temperature*temperature
             - (6.6670e-2/3)*temperature*temperature*temperature
             + (2.8000e-5/4)*pow(temperature, 4.0))/58.44e3
            - 2.045698e+02; // [kJ/kg]
 
        const Evaluation m = S/(1-S)/58.44e-3;
 
        Evaluation d_h = 0;
        for (int i = 0; i<=3; ++i) {
            for (int j = 0; j <= 2; ++j) {
                d_h += a[i][j] * pow(theta, i) * pow(m, j);
            }
        }
 
        const Evaluation delta_h = 4.184/(1e3 + (58.44 * m))*d_h;
 
        // Enthalpy of brine
        const Evaluation h_ls = (1-S)*hw + S*h_NaCl + S*delta_h; // [kJ/kg]
        return h_ls*1e3; // convert to [J/kg]
    }
 
 
    template <class Evaluation>
    static Evaluation liquidHeatCapacity(const Evaluation& temperature,
                                         const Evaluation& pressure)
    {
        Scalar eps = scalarValue(temperature)*1e-8;
        return (liquidEnthalpy(temperature + eps, pressure) - liquidEnthalpy(temperature, pressure))/eps;
    }
 
    template <class Evaluation>
    static Evaluation gasHeatCapacity(const Evaluation& temperature,
                                      const Evaluation& pressure)
    { return H2O::gasHeatCapacity(temperature, pressure); }
 
    template <class Evaluation>
    static Evaluation gasInternalEnergy(const Evaluation& temperature,
                                        const Evaluation& pressure)
    {
        return
            gasEnthalpy(temperature, pressure) -
            pressure/gasDensity(temperature, pressure);
    }
 
    template <class Evaluation>
    static Evaluation liquidInternalEnergy(const Evaluation& temperature,
                                           const Evaluation& pressure)
    {
        return
            liquidEnthalpy(temperature, pressure) -
            pressure/liquidDensity(temperature, pressure);
    }
 
    template <class Evaluation>
    static Evaluation gasDensity(const Evaluation& temperature, const Evaluation& pressure)
    { return H2O::gasDensity(temperature, pressure); }
 
    template <class Evaluation>
    static Evaluation liquidDensity(const Evaluation& temperature, const Evaluation& pressure, bool extrapolate = false)
    {
        Evaluation tempC = temperature - 273.15;
        Evaluation pMPa = pressure/1.0E6;
 
        const Evaluation rhow = H2O::liquidDensity(temperature, pressure, extrapolate);
        return
            rhow +
            1000*salinity*(
                0.668 +
                0.44*salinity +
                1.0E-6*(
                    300*pMPa -
                    2400*pMPa*salinity +
                    tempC*(
                        80.0 -
                        3*tempC -
                        3300*salinity -
                        13*pMPa +
                        47*pMPa*salinity)));
    }
 
    template <class Evaluation>
    static Evaluation gasPressure(const Evaluation& temperature, const Evaluation& density)
    { return H2O::gasPressure(temperature, density); }
 
    template <class Evaluation>
    static Evaluation liquidPressure(const Evaluation& temperature, const Evaluation& density)
    {
        // We use the newton method for this. For the initial value we
        // assume the pressure to be 10% higher than the vapor
        // pressure
        Evaluation pressure = 1.1*vaporPressure(temperature);
        Scalar eps = scalarValue(pressure)*1e-7;
 
        Evaluation deltaP = pressure*2;
        for (int i = 0;
             i < 5
                 && std::abs(scalarValue(pressure)*1e-9) < std::abs(scalarValue(deltaP));
             ++i)
        {
            const Evaluation f = liquidDensity(temperature, pressure) - density;
 
            Evaluation df_dp = liquidDensity(temperature, pressure + eps);
            df_dp -= liquidDensity(temperature, pressure - eps);
            df_dp /= 2*eps;
 
            deltaP = - f/df_dp;
 
            pressure += deltaP;
        }
 
        return pressure;
    }
 
    template <class Evaluation>
    static Evaluation gasViscosity(const Evaluation& temperature, const Evaluation& pressure)
    { return H2O::gasViscosity(temperature, pressure); }
 
    template <class Evaluation>
    static Evaluation liquidViscosity(const Evaluation& temperature, const Evaluation& /*pressure*/)
    {
        Evaluation T_C = temperature - 273.15;
        if(temperature <= 275.) // regularization
            T_C = 275.0;
 
        Evaluation A = (0.42*std::pow((std::pow(salinity, 0.8)-0.17), 2) + 0.045)*pow(T_C, 0.8);
        Evaluation mu_brine = 0.1 + 0.333*salinity + (1.65+91.9*salinity*salinity*salinity)*exp(-A);
 
        return mu_brine/1000.0; // convert to [Pa s] (todo: check if correct cP->Pa s is times 10...)
    }
};
 
template <class Scalar, class H2O>
Scalar Brine<Scalar, H2O>::salinity = 0.1; // also needs to be adapted in CO2 solubility table!
 
} // namespace Opm
 
#endif