From fb68cae145d28556e4d7cc58ffc1ec871e0b0be4 Mon Sep 17 00:00:00 2001
From: Ray Speth <speth@mit.edu>
Date: Fri, 3 Aug 2018 15:18:30 -0400
Subject: [PATCH] [Thermo] Keep PureFluidPhase state data consistent

Previously, calls to setTemperature, setDensity, and setState_TR did not result
in the underlying Substance object being updated. In addition, the
isothermalCompressibility and thermalExpansionCoeff methods did not synchronize
the state.

Now, setting the state of the PureFluidPhase object always sets the state of the
Substance object, and no synchronization is required in property calculation
functions.
---
 include/cantera/thermo/PureFluidPhase.h       |  5 +--
 .../cython/cantera/test/test_purefluid.py     |  5 +++
 src/thermo/PureFluidPhase.cpp                 | 37 +++++++++----------
 3 files changed, 24 insertions(+), 23 deletions(-)

diff --git a/include/cantera/thermo/PureFluidPhase.h b/include/cantera/thermo/PureFluidPhase.h
index 6ea1f83b3..41320c9db 100644
--- a/include/cantera/thermo/PureFluidPhase.h
+++ b/include/cantera/thermo/PureFluidPhase.h
@@ -68,6 +68,8 @@ public:
      * @param p  Pressure (Pa)
      */
     virtual void setPressure(doublereal p);
+    virtual void setTemperature(double T);
+    virtual void setDensity(double rho);
 
     virtual void getChemPotentials(doublereal* mu) const {
         mu[0] = gibbs_mole();
@@ -178,9 +180,6 @@ protected:
      */
     void Set(tpx::PropertyPair::type n, double x, double y) const;
 
-    //! Sets the state using a TPX::TV call
-    void setTPXState() const;
-
 private:
     //! Pointer to the underlying tpx object Substance that does the work
     mutable std::unique_ptr<tpx::Substance> m_sub;
diff --git a/interfaces/cython/cantera/test/test_purefluid.py b/interfaces/cython/cantera/test/test_purefluid.py
index 37ed15715..919fe7276 100644
--- a/interfaces/cython/cantera/test/test_purefluid.py
+++ b/interfaces/cython/cantera/test/test_purefluid.py
@@ -138,6 +138,11 @@ class TestPureFluid(utilities.CanteraTest):
         self.assertNear(ref.thermal_expansion_coeff,
                         self.water.thermal_expansion_coeff, 1e-5)
 
+    def test_thermal_expansion_coeff_TD(self):
+        for T in [440, 550, 660]:
+            self.water.TD = T, 0.1
+            self.assertNear(T * self.water.thermal_expansion_coeff, 1.0, 1e-2)
+
     def test_fd_properties_twophase(self):
         self.water.TX = 400, 0.1
         self.assertEqual(self.water.cp, np.inf)
diff --git a/src/thermo/PureFluidPhase.cpp b/src/thermo/PureFluidPhase.cpp
index b65996888..a51ca4928 100644
--- a/src/thermo/PureFluidPhase.cpp
+++ b/src/thermo/PureFluidPhase.cpp
@@ -85,50 +85,55 @@ double PureFluidPhase::maxTemp(size_t k) const
 
 doublereal PureFluidPhase::enthalpy_mole() const
 {
-    setTPXState();
     return m_sub->h() * m_mw;
 }
 
 doublereal PureFluidPhase::intEnergy_mole() const
 {
-    setTPXState();
     return m_sub->u() * m_mw;
 }
 
 doublereal PureFluidPhase::entropy_mole() const
 {
-    setTPXState();
     return m_sub->s() * m_mw;
 }
 
 doublereal PureFluidPhase::gibbs_mole() const
 {
-    setTPXState();
     return m_sub->g() * m_mw;
 }
 
 doublereal PureFluidPhase::cp_mole() const
 {
-    setTPXState();
     return m_sub->cp() * m_mw;
 }
 
 doublereal PureFluidPhase::cv_mole() const
 {
-    setTPXState();
     return m_sub->cv() * m_mw;
 }
 
 doublereal PureFluidPhase::pressure() const
 {
-    setTPXState();
     return m_sub->P();
 }
 
 void PureFluidPhase::setPressure(doublereal p)
 {
     Set(tpx::PropertyPair::TP, temperature(), p);
-    setDensity(1.0/m_sub->v());
+    ThermoPhase::setDensity(1.0/m_sub->v());
+}
+
+void PureFluidPhase::setTemperature(double T)
+{
+    ThermoPhase::setTemperature(T);
+    Set(tpx::PropertyPair::TV, T, m_sub->v());
+}
+
+void PureFluidPhase::setDensity(double rho)
+{
+    ThermoPhase::setDensity(rho);
+    Set(tpx::PropertyPair::TV, m_sub->Temp(), 1.0/rho);
 }
 
 void PureFluidPhase::Set(tpx::PropertyPair::type n, double x, double y) const
@@ -136,11 +141,6 @@ void PureFluidPhase::Set(tpx::PropertyPair::type n, double x, double y) const
     m_sub->Set(n, x, y);
 }
 
-void PureFluidPhase::setTPXState() const
-{
-    Set(tpx::PropertyPair::TV, temperature(), 1.0/density());
-}
-
 doublereal PureFluidPhase::isothermalCompressibility() const
 {
     return m_sub->isothermalCompressibility();
@@ -356,24 +356,21 @@ doublereal PureFluidPhase::satPressure(doublereal t)
 
 doublereal PureFluidPhase::vaporFraction() const
 {
-    setTPXState();
     return m_sub->x();
 }
 
 void PureFluidPhase::setState_Tsat(doublereal t, doublereal x)
 {
-    setTemperature(t);
-    setTPXState();
     Set(tpx::PropertyPair::TX, t, x);
-    setDensity(1.0/m_sub->v());
+    ThermoPhase::setTemperature(t);
+    ThermoPhase::setDensity(1.0/m_sub->v());
 }
 
 void PureFluidPhase::setState_Psat(doublereal p, doublereal x)
 {
-    setTPXState();
     Set(tpx::PropertyPair::PX, p, x);
-    setTemperature(m_sub->Temp());
-    setDensity(1.0/m_sub->v());
+    ThermoPhase::setTemperature(m_sub->Temp());
+    ThermoPhase::setDensity(1.0/m_sub->v());
 }
 
 std::string PureFluidPhase::report(bool show_thermo, doublereal threshold) const