GibbsExcessVPSSTP.cpp

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/**
 *  @file GibbsExcessVPSSTP.cpp
 *   Definitions for intermediate ThermoPhase object for phases which
 *   employ excess Gibbs free energy formulations
 *  (see \ref thermoprops and class \link Cantera::GibbsExcessVPSSTP GibbsExcessVPSSTP\endlink).
 *
 * Header file for a derived class of ThermoPhase that handles variable pressure
 * standard state methods for calculating thermodynamic properties that are
 * further based upon expressions for the excess Gibbs free energy expressed as
 * a function of the mole fractions.
 */
 
// This file is part of Cantera. See License.txt in the top-level directory or
// at https://cantera.org/license.txt for license and copyright information.
 
#include "cantera/thermo/GibbsExcessVPSSTP.h"
#include "cantera/base/stringUtils.h"
 
using namespace std;
 
namespace Cantera
{
 
void GibbsExcessVPSSTP::compositionChanged()
{
    Phase::compositionChanged();
    getMoleFractions(moleFractions_.data());
}
 
// ------------ Mechanical Properties ------------------------------
 
void GibbsExcessVPSSTP::calcDensity()
{
    vector_fp vbar = getPartialMolarVolumesVector();
    doublereal vtotal = 0.0;
    for (size_t i = 0; i < m_kk; i++) {
        vtotal += vbar[i] * moleFractions_[i];
    }
    doublereal dd = meanMolecularWeight() / vtotal;
    Phase::assignDensity(dd);
}
 
// - Activities, Standard States, Activity Concentrations -----------
 
Units GibbsExcessVPSSTP::standardConcentrationUnits() const
{
    return Units(1.0); // dimensionless
}
 
void GibbsExcessVPSSTP::getActivityConcentrations(doublereal* c) const
{
    getActivities(c);
}
 
doublereal GibbsExcessVPSSTP::standardConcentration(size_t k) const
{
    return 1.0;
}
 
doublereal GibbsExcessVPSSTP::logStandardConc(size_t k) const
{
    return 0.0;
}
 
void GibbsExcessVPSSTP::getActivities(doublereal* ac) const
{
    getActivityCoefficients(ac);
    getMoleFractions(moleFractions_.data());
    for (size_t k = 0; k < m_kk; k++) {
        ac[k] *= moleFractions_[k];
    }
}
 
void GibbsExcessVPSSTP::getActivityCoefficients(doublereal* const ac) const
{
    getLnActivityCoefficients(ac);
    for (size_t k = 0; k < m_kk; k++) {
        if (ac[k] > 700.) {
            ac[k] = exp(700.0);
        } else if (ac[k] < -700.) {
            ac[k] = exp(-700.0);
        } else {
            ac[k] = exp(ac[k]);
        }
    }
}
 
// ------------ Partial Molar Properties of the Solution ------------
 
void GibbsExcessVPSSTP::getPartialMolarVolumes(doublereal* vbar) const
{
    // Get the standard state values in m^3 kmol-1
    getStandardVolumes(vbar);
}
 
const vector_fp& GibbsExcessVPSSTP::getPartialMolarVolumesVector() const
{
    return getStandardVolumes();
}
 
double GibbsExcessVPSSTP::checkMFSum(const doublereal* const x) const
{
    doublereal norm = std::accumulate(x, x + m_kk, 0.0);
    if (fabs(norm - 1.0) > 1.0E-9) {
        throw CanteraError("GibbsExcessVPSSTP::checkMFSum",
            "(MF sum - 1) exceeded tolerance of 1.0E-9: {}", norm);
    }
    return norm;
}
 
bool GibbsExcessVPSSTP::addSpecies(shared_ptr<Species> spec)
{
    bool added = VPStandardStateTP::addSpecies(spec);
    if (added) {
        if (m_kk == 1) {
            moleFractions_.push_back(1.0);
        } else {
            moleFractions_.push_back(0.0);
        }
        lnActCoeff_Scaled_.push_back(0.0);
        dlnActCoeffdT_Scaled_.push_back(0.0);
        d2lnActCoeffdT2_Scaled_.push_back(0.0);
        dlnActCoeffdlnX_diag_.push_back(0.0);
        dlnActCoeffdlnN_diag_.push_back(0.0);
        dlnActCoeffdlnN_.resize(m_kk, m_kk);
    }
    return added;
}
 
} // end of namespace Cantera