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Implement and test MaskellSolidSolnPhase::getActivityCoefficients().

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This commit is contained in:
Victor Brunini 2014-03-07 00:53:33 +00:00
parent 7abb459bbe
commit 0981391ac4
3 changed files with 57 additions and 12 deletions
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1
include/cantera/thermo/MaskellSolidSolnPhase.h
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@ -349,6 +349,7 @@ protected:
//! Index of the species whose mole fraction defines the extent of reduction r
int product_species_index;
int reactant_species_index;
private:
// Functions to calculate some of the pieces of the mixing terms.

40
src/thermo/MaskellSolidSolnPhase.cpp
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@ -29,7 +29,8 @@ MaskellSolidSolnPhase::MaskellSolidSolnPhase() :
m_g0_RT(2),
m_s0_R(2),
h_mixing(0.0),
product_species_index(0)
product_species_index(0),
reactant_species_index(1)
{
}
//=====================================================================================================
@ -42,7 +43,8 @@ MaskellSolidSolnPhase::MaskellSolidSolnPhase(const MaskellSolidSolnPhase& b) :
m_g0_RT(2),
m_s0_R(2),
h_mixing(0.0),
product_species_index(0)
product_species_index(0),
reactant_species_index(1)
{
*this = b;
}
@ -163,8 +165,17 @@ void MaskellSolidSolnPhase::setMolarDensity(const doublereal n)
void MaskellSolidSolnPhase::
getActivityCoefficients(doublereal* ac) const
{
// throw CanteraError("MaskellSolidSolnPhase::getActivityCoefficients()",
// "needs to be implemented");
_updateThermo();
const doublereal r = moleFraction(product_species_index);
const doublereal pval = p(r);
const doublereal fmval = fm(r);
const doublereal rfm = r * fmval;
const doublereal RT = GasConstant * temperature();
const doublereal A = (std::pow(1 - rfm, pval) * std::pow(rfm, pval) * std::pow(r - rfm, 1 - pval)) /
(std::pow(1 - r - rfm, 1 + pval) * (1 - r));
const doublereal B = pval * h_mixing / RT;
ac[product_species_index] = 1 / (A * r * r) * std::exp(-B);
ac[reactant_species_index] = A * r / (1 - r) * std::exp(B);
}
void MaskellSolidSolnPhase::
@ -176,12 +187,12 @@ getChemPotentials(doublereal* mu) const
const doublereal fmval = fm(r);
const doublereal rfm = r * fmval;
const doublereal RT = GasConstant * temperature();
const doublereal muDelta = -pval * h_mixing - GasConstant * temperature()
* std::log( (std::pow(1 - rfm, pval) * std::pow(rfm, pval) * std::pow(r - rfm, 1 - pval) * r) /
(std::pow(1 - r - rfm, 1 + pval) * (1 - r)) );
const int sign = (product_species_index == 0) ? 1 : -1;
mu[0] = RT * m_g0_RT[0] + sign * muDelta;
mu[1] = RT * m_g0_RT[1] - sign * muDelta;
const doublereal DgbarDr = pval * h_mixing +
GasConstant * temperature() *
std::log( (std::pow(1 - rfm, pval) * std::pow(rfm, pval) * std::pow(r - rfm, 1 - pval) * r) /
(std::pow(1 - r - rfm, 1 + pval) * (1 - r)) );
mu[product_species_index] = RT * m_g0_RT[product_species_index] - DgbarDr;
mu[reactant_species_index] = RT * m_g0_RT[reactant_species_index] + DgbarDr;
}
void MaskellSolidSolnPhase::
@ -280,12 +291,17 @@ void MaskellSolidSolnPhase::initThermoXML(XML_Node& phaseNode, const std::string
XML_Node& scNode = thNode.child("product_species");
std::string product_species_name = scNode.value();
product_species_index = speciesIndex(product_species_name);
if( product_species_index == npos )
if( product_species_index == static_cast<int>(npos) )
{
throw CanteraError(subname.c_str(),
"Species " + product_species_name + " not found.");
}
std::cout << "parsed product_species_index = " << product_species_index << std::endl;
if( product_species_index == 0 )
{
reactant_species_index = 1;
} else {
reactant_species_index = 0;
}
}
} else {

28
test/thermo/MaskellSolidSolnPhase_Test.cpp
View file

@ -63,6 +63,7 @@ TEST_F(MaskellSolidSolnPhase_Test, chem_potentials)
set_r(0.5);
MaskellSolidSolnPhase * maskell_phase = dynamic_cast<MaskellSolidSolnPhase *>(test_phase);
ASSERT_TRUE(maskell_phase != NULL);
maskell_phase->set_h_mix(0.);
const double expected_result_0[9] = {1.2338461168724738e7, 8.011774549216799e6, 4.990989640314685e6, 2.415973128783114e6, 0., -2.415973128783114e6, -4.99098964031469e6, -8.0117745492168e6, -1.2338461168724738e7};
@ -77,6 +78,33 @@ TEST_F(MaskellSolidSolnPhase_Test, chem_potentials)
check_chemPotentials(expected_result_minus_5000);
}
TEST_F(MaskellSolidSolnPhase_Test, activityCoeffs)
{
const std::string valid_file("../data/MaskellSolidSolnPhase_valid.xml");
initializeTestPhaseWithXML(valid_file);
test_phase->setState_TP(298., 1.);
set_r(0.5);
MaskellSolidSolnPhase * maskell_phase = dynamic_cast<MaskellSolidSolnPhase *>(test_phase);
ASSERT_TRUE(maskell_phase != NULL);
// Test that mu0 + RT log(activityCoeff * MoleFrac) == mu
const double RT = GasConstant * 298.;
std::vector<double> mu0(2);
std::vector<double> activityCoeffs(2);
std::vector<double> chemPotentials(2);
for(int i=0; i < 9; ++i)
{
const double r = 0.1 * (i+1);
set_r(r);
test_phase->getChemPotentials(&chemPotentials[0]);
test_phase->getActivityCoefficients(&activityCoeffs[0]);
test_phase->getStandardChemPotentials(&mu0[0]);
EXPECT_NEAR(chemPotentials[0], mu0[0] + RT*std::log(activityCoeffs[0] * r), 1.e-6);
EXPECT_NEAR(chemPotentials[1], mu0[1] + RT*std::log(activityCoeffs[1] * (1-r)), 1.e-6);
}
}
TEST_F(MaskellSolidSolnPhase_Test, partialMolarVolumes)
{
const std::string valid_file("../data/MaskellSolidSolnPhase_valid.xml");