Make the gas constant an adjustable parameter and update to CODATA 20…

…14 value
CoolProp · Apr 8, 2016 · cd996fb · cd996fb
1 parent 616d775
commit cd996fb
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Showing 4 changed files with 4 additions and 5 deletions.
diff --git a/include/Configuration.h b/include/Configuration.h
@@ -32,6 +32,7 @@
     X(DONT_CHECK_PROPERTY_LIMITS, "DONT_CHECK_PROPERTY_LIMITS", false, "If true, when possible, CoolProp will skip checking whether values are inside the property limits") \
 	X(HENRYS_LAW_TO_GENERATE_VLE_GUESSES, "HENRYS_LAW_TO_GENERATE_VLE_GUESSES", false, "If true, when doing water-based mixture dewpoint calculations, use Henry's Law to generate guesses for liquid-phase composition") \
     X(PHASE_ENVELOPE_STARTING_PRESSURE_PA, "PHASE_ENVELOPE_STARTING_PRESSURE_PA", 100.0, "Starting pressure [Pa] for phase envelope construction") \
+    X(R_U_CODATA, "R_U_CODATA", 8.3144598, "The value for the ideal gas constant in J/mol/K according to CODATA 2014.  This value is used to harmonize all the ideal gas constants. This is especially important in the critical region.") \
 
  // Use preprocessor to create the Enum
  enum configuration_keys{

diff --git a/include/DataStructures.h b/include/DataStructures.h
@@ -197,8 +197,6 @@ std::string get_csv_parameter_list();
 /// These are constants for the compositions
 enum composition_types{IFRAC_MASS, IFRAC_MOLE, IFRAC_VOLUME, IFRAC_UNDEFINED, IFRAC_PURE};
 
-const CoolPropDbl R_u_CODATA = 8.3144621; ///< The value for the ideal gas constant in J/mol/K according to CODATA 2010.  This value is used to harmonize all the ideal gas constants.  This is especially important in the critical region.
-
 /// These are unit types for the fluid
 enum fluid_types{FLUID_TYPE_PURE, FLUID_TYPE_PSEUDOPURE, FLUID_TYPE_REFPROP, FLUID_TYPE_INCOMPRESSIBLE_LIQUID, FLUID_TYPE_INCOMPRESSIBLE_SOLUTION, FLUID_TYPE_UNDEFINED};
 

diff --git a/src/AbstractState.cpp b/src/AbstractState.cpp
@@ -76,10 +76,10 @@ AbstractState * AbstractState::factory(const std::string &backend, const std::ve
         throw ValueError("TREND backend not yet implemented");
     }
     else if (backend == "SRK"){
-        return new SRKBackend(fluid_names, R_u_CODATA);
+        return new SRKBackend(fluid_names, get_config_double(R_U_CODATA));
     }
     else if (backend == "PR" || backend == "Peng-Robinson"){
-        return new PengRobinsonBackend(fluid_names, R_u_CODATA);
+        return new PengRobinsonBackend(fluid_names, get_config_double(R_u_CODATA));
     }
     else if (!backend.compare("?") || backend.empty())
     {

diff --git a/src/Backends/Helmholtz/HelmholtzEOSMixtureBackend.cpp b/src/Backends/Helmholtz/HelmholtzEOSMixtureBackend.cpp
@@ -348,7 +348,7 @@ CoolPropDbl HelmholtzEOSMixtureBackend::calc_gas_constant(void)
     }
     else{
         if (get_config_bool(NORMALIZE_GAS_CONSTANTS)){
-            return R_u_CODATA;
+            return get_config_double(R_U_CODATA);
         }
         else{
             // mass fraction weighted average of the components