Fixes ConstDensityThermo::standardConcentration()

`ConstDensityThermo::standardConcentration(k)` is now calculated as `density()/molecularWeight(k)`, rather than the previously incorrect `molarDemsity()`. Note that this causes a problem for any species where `molecularWeight(k)=0` (i.e. vacancies). Such species should be avoided, in this phase model. For that reason, `sofc-test.xml` is changed so that the oxide bulk is modeled as an `IdealSolidSolution`
Cantera · Dec 5, 2017 · 90474dd · 90474dd
1 parent 17dfa2d
commit 90474dd
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Showing 2 changed files with 39 additions and 32 deletions.
diff --git a/src/thermo/ConstDensityThermo.cpp b/src/thermo/ConstDensityThermo.cpp
@@ -59,7 +59,7 @@ void ConstDensityThermo::getActivityCoefficients(doublereal* ac) const
 
 doublereal ConstDensityThermo::standardConcentration(size_t k) const
 {
-    return molarDensity();
+    return density()/molecularWeight(k);
 }
 
 void ConstDensityThermo::getChemPotentials(doublereal* mu) const

diff --git a/test/data/sofc-test.xml b/test/data/sofc-test.xml
@@ -33,18 +33,19 @@
 
   <!-- phase oxide_bulk     -->
   <phase dim="3" id="oxide_bulk">
-    <elementArray datasrc="elements.xml">O E</elementArray>
-    <speciesArray datasrc="#species_data">Ox VO**</speciesArray>
-    <state>
-      <temperature units="K">1073.15</temperature>
-      <pressure units="Pa">101325.0</pressure>
-      <moleFractions>Ox:0.95 VO**:0.05</moleFractions>
-    </state>
-    <thermo model="Incompressible">
-      <density units="g/cm3">0.7</density>
-    </thermo>
-    <transport model="None"/>
-    <kinetics model="none"/>
+      <elementArray datasrc="elements.xml">O E</elementArray>
+      <speciesArray datasrc="#species_data">Ox VO**</speciesArray>
+      <state>
+          <temperature units="K">1073.15</temperature>
+          <pressure units="Pa">101325.0</pressure>
+          <moleFractions>Ox:0.95 VO**:0.05</moleFractions>
+      </state>
+      <thermo model="IdealSolidSolution">
+          <density units="g/cm3">0.7</density>
+      </thermo>
+      <standardConc model="unity"/>
+      <transport model="None"/>
+      <kinetics model="none"/>
   </phase>
 
   <!-- phase metal_surface     -->
@@ -123,29 +124,35 @@
 
     <!-- species VO**    -->
     <species name="VO**">
-      <atomArray/>
-      <thermo>
-        <const_cp Tmax="5000.0" Tmin="100.0">
-           <t0 units="K">298.15</t0>
-           <h0 units="kJ/mol">0.0</h0>
-           <s0 units="J/mol/K">0.0</s0>
-           <cp0 units="J/mol/K">0.0</cp0>
-        </const_cp>
-      </thermo>
+        <atomArray/>
+        <thermo>
+            <const_cp Tmax="5000.0" Tmin="100.0">
+                <t0 units="K">298.15</t0>
+                <h0 units="kJ/mol">0.0</h0>
+                <s0 units="J/mol/K">0.0</s0>
+                <cp0 units="J/mol/K">0.0</cp0>
+            </const_cp>
+        </thermo>
+        <standardState>
+            <molarVolume>0.0018</molarVolume>
+        </standardState>
     </species>
 
     <!-- species Ox    -->
     <species name="Ox">
-      <atomArray>E:2 O:1 </atomArray>
-      <charge>-2</charge>
-      <thermo>
-        <const_cp Tmax="5000.0" Tmin="100.0">
-           <t0 units="K">298.15</t0>
-           <h0 units="kJ/mol">-170.0</h0>
-           <s0 units="J/K/mol">50.0</s0>
-           <cp0 units="J/mol/K">0.0</cp0>
-        </const_cp>
-      </thermo>
+        <atomArray>E:2 O:1 </atomArray>
+        <charge>-2</charge>
+        <thermo>
+            <const_cp Tmax="5000.0" Tmin="100.0">
+                <t0 units="K">298.15</t0>
+                <h0 units="kJ/mol">-170.0</h0>
+                <s0 units="J/K/mol">50.0</s0>
+                <cp0 units="J/mol/K">0.0</cp0>
+            </const_cp>
+        </thermo>
+        <standardState>
+            <molarVolume>0.0018</molarVolume>
+        </standardState>
     </species>
 
     <!-- species (m)    -->