[Thermo] Use current partial molar volumes in BinarySolutionTabulated…

…Thermo Previously, calculations of partial molar enthalpies, entropies, and chemical potentials were using the pure-species molar volumes rather than the ones calculated by inverting the tabulated mixture molar volume.
Cantera · Mar 4, 2023 · f19bd3f · f19bd3f
1 parent 8658c1b
commit f19bd3f
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Showing 4 changed files with 42 additions and 41 deletions.
diff --git a/include/cantera/thermo/IdealSolidSolnPhase.h b/include/cantera/thermo/IdealSolidSolnPhase.h
@@ -596,9 +596,10 @@ class IdealSolidSolnPhase : public ThermoPhase
 
     //! Vector of molar volumes for each species in the solution
     /**
-     * Species molar volumes \f$ m^3 kmol^-1 \f$
+     * Species molar volumes (\f$ m^3 kmol^-1 \f$) at the current mixture state.
+     * For the IdealSolidSolnPhase class, these are constant.
      */
-    vector_fp m_speciesMolarVolume;
+    mutable vector_fp m_speciesMolarVolume;
 
     //! Vector containing the species reference enthalpies at T = m_tlast
     mutable vector_fp m_h0_RT;

diff --git a/src/thermo/BinarySolutionTabulatedThermo.cpp b/src/thermo/BinarySolutionTabulatedThermo.cpp
@@ -199,17 +199,18 @@ void BinarySolutionTabulatedThermo::diff(const vector_fp& inputData,
 
 void BinarySolutionTabulatedThermo::getPartialMolarVolumes(double* vbar) const
 {
-    double Xtab = moleFraction(m_kk_tab);
-    double Vm = interpolate(Xtab, m_molar_volume_tab);
-    double dVdX_tab = interpolate(Xtab, m_derived_molar_volume_tab);
-    vbar[m_kk_tab] = Vm + (1 - Xtab) * dVdX_tab;
-    vbar[1-m_kk_tab] = Vm - Xtab * dVdX_tab;
+    std::copy(m_speciesMolarVolume.begin(), m_speciesMolarVolume.end(), vbar);
 }
 
 void BinarySolutionTabulatedThermo::calcDensity()
 {
-    double vmol = interpolate(moleFraction(m_kk_tab), m_molar_volume_tab);
-    double dens = meanMolecularWeight()/vmol;
+    double Xtab = moleFraction(m_kk_tab);
+    double Vm = interpolate(Xtab, m_molar_volume_tab);
+    double dVdX_tab = interpolate(Xtab, m_derived_molar_volume_tab);
+    m_speciesMolarVolume[m_kk_tab] = Vm + (1 - Xtab) * dVdX_tab;
+    m_speciesMolarVolume[1-m_kk_tab] = Vm - Xtab * dVdX_tab;
+
+    double dens = meanMolecularWeight() / Vm;
 
     // Set the density in the parent State object directly, by calling the
     // Phase::assignDensity() function.

diff --git a/test/data/consistency-cases.yaml b/test/data/consistency-cases.yaml
@@ -97,11 +97,10 @@ binary-solution-tabulated:
     file: BinarySolutionTabulatedThermo.yaml
     phase: anode
     known-failures:
-      g_eq_h_minus_Ts: "Inconsistent results when P != 1 atm. See GitHub Issue #1301"
-      g_eq_sum_gk_Xk: "Inconsistent results when P != 1 atm. See GitHub Issue #1301"
-      h_eq_sum_hk_Xk: "Inconsistent results. See GitHub Issue #1302"
-      s_eq_sum_sk_Xk: "Problems near composition limit. See GitHub Issue #1303"
-      gk_eq_hk_minus_T_sk: "Problems near composition limit. See GitHub Issue #1303"
+      g_eq_h_minus_Ts/4: "Problems near composition limit. See GitHub Issue #1303"
+      g_eq_sum_gk_Xk/4: "Problems near composition limit. See GitHub Issue #1303"
+      s_eq_sum_sk_Xk/4: "Problems near composition limit. See GitHub Issue #1303"
+      gk_eq_hk_minus_T_sk/[34]: "Problems near composition limit. See GitHub Issue #1303"
       gk0_eq_hk0_minus_T_sk0/[34]:
         "Problems near composition limit. See GitHub Issue #1303"
       chem_potentials_to_activities/3:

diff --git a/test/thermo/BinarySolutionTabulatedThermo_Test.cpp b/test/thermo/BinarySolutionTabulatedThermo_Test.cpp
@@ -58,15 +58,15 @@ TEST_F(BinarySolutionTabulatedThermo_Test,interp_s)
     test_phase->setState_TP(298.15, 101325.);
     // These expected results are purely a regression test
     const double expected_result[9] = {
-        3839.8896914480647,
-        5260.8983334513332,
-        5764.7097019695211,
-        7786.429533070881,
-        10411.474081913055,
-        15276.785945165157,
-        17900.243436157067,
-        22085.482962782506,
-        25989.144060372793
+        3839.8897013463629,
+        5260.8983501505654,
+        5764.7097249117705,
+        7786.4295622389736,
+        10411.474117668258,
+        15276.785988429341,
+        17900.243488318705,
+        22085.483025077028,
+        25989.144133134443
     };
 
     double xmin = 0.10;
@@ -90,15 +90,15 @@ TEST_F(BinarySolutionTabulatedThermo_Test,chem_potentials)
     test_phase->setState_TP(298.15,101325.);
     // These expected results are purely a regression test
     const double expected_result[9] = {
-        -19347891.714810669,
-        -14757822.388050893,
-        -12593133.605195494,
-        -12626837.865623865,
-        -12131010.479908356,
-        -10322881.86739888,
-        - 9573869.8636945337,
-        -10260863.826955771,
-        -10579827.307551134
+        -19347891.744322445,
+        -14757822.415520553,
+        -12593133.63125352,
+        -12626837.890922677,
+        -12131010.504991682,
+        -10322881.892878814,
+        -9573869.8901660107,
+        -10260863.854728648,
+        -10579827.336476315
     };
 
     double xmin = 0.10;
@@ -120,15 +120,15 @@ TEST_F(BinarySolutionTabulatedThermo_Test,partialMolarEntropies)
     test_phase->setState_TP(298.15,101325.);
     // These expected results are purely a regression test
     const double expected_result[9] = {
-        30514.752294683516,
-        21514.841983025333,
-        14848.02859501992,
-        15965.482659621264,
-        18272.567242414199,
-        24453.517437971925,
-        25299.003664716853,
-        28474.69918493319,
-        30810.094532734405
+        30514.752393666495,
+        21514.842075159024,
+        14848.028682418964,
+        15965.482744473897,
+        18272.567326544096,
+        24453.517523432041,
+        25299.003753502617,
+        28474.699278083881,
+        30810.094629749936
     };
 
     double xmin = 0.10;