MolalityVPSSTP Class Reference

MolalityVPSSTP is a derived class of ThermoPhase that handles variable pressure standard state methods for calculating thermodynamic properties that are further based on molality-scaled activities. More...

#include <MolalityVPSSTP.h>

Inheritance diagram for MolalityVPSSTP:

Detailed Description

MolalityVPSSTP is a derived class of ThermoPhase that handles variable pressure standard state methods for calculating thermodynamic properties that are further based on molality-scaled activities.

This category incorporates most of the methods for calculating liquid electrolyte thermodynamics that have been developed since the 1970's.

This class adds additional functions onto the ThermoPhase interface that handle molality based standard states. The ThermoPhase class includes a member function, ThermoPhase::activityConvention() that indicates which convention the activities are based on. The default is to assume activities are based on the molar convention. However, classes which derive from the MolalityVPSSTP class return cAC_CONVENTION_MOLALITY from this member function.

The molality of a solute, \( m_i \), is defined as

\[ m_i = \frac{n_i}{\tilde{M}_o n_o} \]

where

\[ \tilde{M}_o = \frac{M_o}{1000} \]

where \( M_o \) is the molecular weight of the solvent. The molality has units of gmol/kg. For the solute, the molality may be considered as the amount of gmol's of solute per kg of solvent, a natural experimental quantity.

The formulas for calculating mole fractions if given the molalities of the solutes is stated below. First calculate \( L^{sum} \), an intermediate quantity.

\[ L^{sum} = \frac{1}{\tilde{M}_o X_o} = \frac{1}{\tilde{M}_o} + \sum_{i\ne o} m_i \]

Then,

\[ X_o = \frac{1}{\tilde{M}_o L^{sum}} \]

\[ X_i = \frac{m_i}{L^{sum}} \]

where \( X_o \) is the mole fraction of solvent, and \( X_o \) is the mole fraction of solute i. Thus, the molality scale and the mole fraction scale offer a one-to-one mapping between each other, except in the limit of a zero solvent mole fraction.

The standard states for thermodynamic objects that derive from MolalityVPSSTP are on the unit molality basis. Chemical potentials of the solutes, \( \mu_k \), and the solvent, \( \mu_o \), which are based on the molality form, have the following general format:

\[ \mu_k = \mu^{\triangle}_k(T,P) + R T \ln(\gamma_k^{\triangle} \frac{m_k}{m^\triangle}) \]

\[ \mu_o = \mu^o_o(T,P) + RT \ln(a_o) \]

where \( \gamma_k^{\triangle} \) is the molality based activity coefficient for species \( k \).

The chemical potential of the solvent is thus expressed in a different format than the chemical potential of the solutes. Additionally, the activity of the solvent, \( a_o \), is further reexpressed in terms of an osmotic coefficient, \( \phi \).

\[ \phi = \frac{- \ln(a_o)}{\tilde{M}_o \sum_{i \ne o} m_i} \]

MolalityVPSSTP::osmoticCoefficient() returns the value of \( \phi \). Note there are a few of definitions of the osmotic coefficient floating around. We use the one defined in (Activity Coefficients in Electrolyte Solutions, K. S. Pitzer CRC Press, Boca Raton, 1991, p. 85, Eqn. 28). This definition is most clearly related to theoretical calculation.

The molar-based activity coefficients \( \gamma_k \) may be calculated from the molality-based activity coefficients, \( \gamma_k^\triangle \) by the following formula.

\[ \gamma_k = \frac{\gamma_k^\triangle}{X_o} \]

For purposes of establishing a convention, the molar activity coefficient of the solvent is set equal to the molality-based activity coefficient of the solvent:

\[ \gamma_o = \gamma_o^\triangle \]

The molality-based and molarity-based standard states may be related to one another by the following formula.

\[ \mu_k^\triangle(T,P) = \mu_k^o(T,P) + R T \ln(\tilde{M}_o m^\triangle) \]

An important convention is followed in all routines that derive from MolalityVPSSTP. Standard state thermodynamic functions and reference state thermodynamic functions return the molality-based quantities. Also all functions which return activities return the molality-based activities. The reason for this convention has been discussed in supporting memos. However, it's important because the term in the equation above is non-trivial. For example it's equal to 2.38 kcal/gmol for water at 298 K.

In order to prevent a singularity, this class includes the concept of a minimum value for the solvent mole fraction. All calculations involving the formulation of activity coefficients and other non-ideal solution behavior adhere to this concept of a minimal value for the solvent mole fraction. This makes sense because these solution behavior were all designed and measured far away from the zero solvent singularity condition and are not applicable in that limit.

This objects add a layer that supports molality. It inherits from VPStandardStateTP.

All objects that derive from this are assumed to have molality based standard states.

Molality based activity coefficients are scaled according to the current pH scale. See the Eq3/6 manual for details.

Activity coefficients for species k may be altered between scales s1 to s2 using the following formula

\[ \ln(\gamma_k^{s2}) = \ln(\gamma_k^{s1}) + \frac{z_k}{z_j} \left( \ln(\gamma_j^{s2}) - \ln(\gamma_j^{s1}) \right) \]

where j is any one species. For the NBS scale, j is equal to the Cl- species and

\[ \ln(\gamma_{Cl-}^{s2}) = \frac{-A_{\phi} \sqrt{I}}{1.0 + 1.5 \sqrt{I}} \]

The Pitzer scale doesn't actually change anything. The pitzer scale is defined as the raw unscaled activity coefficients produced by the underlying objects.

SetState Strategy

The MolalityVPSSTP object does not have a setState strategy concerning the molalities. It does not keep track of whether the molalities have changed. It's strictly an interfacial layer that writes the current mole fractions to the State object. When molalities are needed it recalculates the molalities from the State object's mole fraction vector.

Todo:

Make two solvent minimum fractions. One would be for calculation of the non-ideal factors. The other one would be for purposes of stoichiometry evaluation. the stoichiometry evaluation one would be a 1E-13 limit. Anything less would create problems with roundoff error.

Definition at line 226 of file MolalityVPSSTP.h.

Public Member Functions
	MolalityVPSSTP ()
	Default Constructor.
void	setState_TPM (double t, double p, const double *const molalities)
	Set the temperature (K), pressure (Pa), and molalities (gmol kg-1) of the solutes.
void	setState_TPM (double t, double p, const Composition &m)
	Set the temperature (K), pressure (Pa), and molalities.
void	setState_TPM (double t, double p, const string &m)
	Set the temperature (K), pressure (Pa), and molalities.
void	setState (const AnyMap &state) override
	Set the state using an AnyMap containing any combination of properties supported by the thermodynamic model.
void	getdlnActCoeffdlnN (const size_t ld, double *const dlnActCoeffdlnN) override
	Get the array of derivatives of the log activity coefficients with respect to the log of the species mole numbers.
string	report (bool show_thermo=true, double threshold=1e-14) const override
	returns a summary of the state of the phase as a string
Utilities
string	phaseOfMatter () const override
	String indicating the mechanical phase of the matter in this Phase.
void	setpHScale (const int pHscaleType)
	Set the pH scale, which determines the scale for single-ion activity coefficients.
int	pHScale () const
	Reports the pH scale, which determines the scale for single-ion activity coefficients.
Utilities for Solvent ID and Molality
void	setMoleFSolventMin (double xmolSolventMIN)
	Sets the minimum mole fraction in the molality formulation.
double	moleFSolventMin () const
	Returns the minimum mole fraction in the molality formulation.
void	calcMolalities () const
	Calculates the molality of all species and stores the result internally.
void	getMolalities (double *const molal) const
	This function will return the molalities of the species.
void	setMolalities (const double *const molal)
	Set the molalities of the solutes in a phase.
void	setMolalitiesByName (const Composition &xMap)
	Set the molalities of a phase.
void	setMolalitiesByName (const string &name)
	Set the molalities of a phase.
Activities, Standard States, and Activity Concentrations
The activity \( a_k \) of a species in solution is related to the chemical potential by \[ \mu_k = \mu_k^0(T) + \hat R T \ln a_k. \] The quantity \( \mu_k^0(T,P) \) is the chemical potential at unit activity, which depends only on temperature and pressure.
int	activityConvention () const override
	We set the convention to molality here.
void	getActivityConcentrations (double *c) const override
	This method returns an array of generalized concentrations.
double	standardConcentration (size_t k=0) const override
	Return the standard concentration for the kth species.
void	getActivities (double *ac) const override
	Get the array of non-dimensional activities (molality based for this class and classes that derive from it) at the current solution temperature, pressure, and solution concentration.
void	getActivityCoefficients (double *ac) const override
	Get the array of non-dimensional activity coefficients at the current solution temperature, pressure, and solution concentration.
virtual void	getMolalityActivityCoefficients (double *acMolality) const
	Get the array of non-dimensional molality based activity coefficients at the current solution temperature, pressure, and solution concentration.
virtual double	osmoticCoefficient () const
	Calculate the osmotic coefficient.
Initialization
The following methods are used in the process of constructing the phase and setting its parameters from a specification in an input file. They are not normally used in application programs. To see how they are used, see importPhase().
bool	addSpecies (shared_ptr< Species > spec) override
	Add a Species to this Phase.
void	initThermo () override
	Initialize the ThermoPhase object after all species have been set up.
Public Member Functions inherited from VPStandardStateTP
void	setTemperature (const double temp) override
	Set the temperature of the phase.
void	setPressure (double p) override
	Set the internally stored pressure (Pa) at constant temperature and composition.
void	setState_TP (double T, double pres) override
	Set the temperature and pressure at the same time.
double	pressure () const override
	Returns the current pressure of the phase.
virtual void	updateStandardStateThermo () const
	Updates the standard state thermodynamic functions at the current T and P of the solution.
double	minTemp (size_t k=npos) const override
	Minimum temperature for which the thermodynamic data for the species or phase are valid.
double	maxTemp (size_t k=npos) const override
	Maximum temperature for which the thermodynamic data for the species are valid.
PDSS *	providePDSS (size_t k)
const PDSS *	providePDSS (size_t k) const
	VPStandardStateTP ()
	Constructor.
bool	isCompressible () const override
	Return whether phase represents a compressible substance.
int	standardStateConvention () const override
	This method returns the convention used in specification of the standard state, of which there are currently two, temperature based, and variable pressure based.
void	getChemPotentials_RT (double *mu) const override
	Get the array of non-dimensional species chemical potentials.
void	getStandardChemPotentials (double *mu) const override
	Get the array of chemical potentials at unit activity for the species at their standard states at the current T and P of the solution.
void	getEnthalpy_RT (double *hrt) const override
	Get the nondimensional Enthalpy functions for the species at their standard states at the current T and P of the solution.
void	getEntropy_R (double *sr) const override
	Get the array of nondimensional Entropy functions for the standard state species at the current T and P of the solution.
void	getGibbs_RT (double *grt) const override
	Get the nondimensional Gibbs functions for the species in their standard states at the current T and P of the solution.
void	getPureGibbs (double *gpure) const override
	Get the Gibbs functions for the standard state of the species at the current T and P of the solution.
void	getIntEnergy_RT (double *urt) const override
	Returns the vector of nondimensional Internal Energies of the standard state species at the current T and P of the solution.
void	getCp_R (double *cpr) const override
	Get the nondimensional Heat Capacities at constant pressure for the species standard states at the current T and P of the solution.
void	getStandardVolumes (double *vol) const override
	Get the molar volumes of the species standard states at the current T and P of the solution.
virtual const vector< double > &	getStandardVolumes () const
void	initThermo () override
	Initialize the ThermoPhase object after all species have been set up.
void	getSpeciesParameters (const string &name, AnyMap &speciesNode) const override
	Get phase-specific parameters of a Species object such that an identical one could be reconstructed and added to this phase.
bool	addSpecies (shared_ptr< Species > spec) override
	Add a Species to this Phase.
void	installPDSS (size_t k, unique_ptr< PDSS > &&pdss)
	Install a PDSS object for species k
virtual bool	addSpecies (shared_ptr< Species > spec)
	Add a Species to this Phase.
void	getEnthalpy_RT_ref (double *hrt) const override
	Returns the vector of nondimensional enthalpies of the reference state at the current temperature of the solution and the reference pressure for the species.
void	getGibbs_RT_ref (double *grt) const override
	Returns the vector of nondimensional Gibbs Free Energies of the reference state at the current temperature of the solution and the reference pressure for the species.
void	getGibbs_ref (double *g) const override
	Returns the vector of the Gibbs function of the reference state at the current temperature of the solution and the reference pressure for the species.
void	getEntropy_R_ref (double *er) const override
	Returns the vector of nondimensional entropies of the reference state at the current temperature of the solution and the reference pressure for each species.
void	getCp_R_ref (double *cprt) const override
	Returns the vector of nondimensional constant pressure heat capacities of the reference state at the current temperature of the solution and reference pressure for each species.
void	getStandardVolumes_ref (double *vol) const override
	Get the molar volumes of the species reference states at the current T and P_ref of the solution.
Public Member Functions inherited from ThermoPhase
	ThermoPhase ()=default
	Constructor.
double	RT () const
	Return the Gas Constant multiplied by the current temperature.
double	equivalenceRatio () const
	Compute the equivalence ratio for the current mixture from available oxygen and required oxygen.
string	type () const override
	String indicating the thermodynamic model implemented.
virtual bool	isIdeal () const
	Boolean indicating whether phase is ideal.
virtual double	refPressure () const
	Returns the reference pressure in Pa.
double	Hf298SS (const size_t k) const
	Report the 298 K Heat of Formation of the standard state of one species (J kmol-1)
virtual void	modifyOneHf298SS (const size_t k, const double Hf298New)
	Modify the value of the 298 K Heat of Formation of one species in the phase (J kmol-1)
virtual void	resetHf298 (const size_t k=npos)
	Restore the original heat of formation of one or more species.
bool	chargeNeutralityNecessary () const
	Returns the chargeNeutralityNecessity boolean.
virtual double	enthalpy_mole () const
	Molar enthalpy. Units: J/kmol.
virtual double	intEnergy_mole () const
	Molar internal energy. Units: J/kmol.
virtual double	entropy_mole () const
	Molar entropy. Units: J/kmol/K.
virtual double	gibbs_mole () const
	Molar Gibbs function. Units: J/kmol.
virtual double	cp_mole () const
	Molar heat capacity at constant pressure. Units: J/kmol/K.
virtual double	cv_mole () const
	Molar heat capacity at constant volume. Units: J/kmol/K.
virtual double	isothermalCompressibility () const
	Returns the isothermal compressibility. Units: 1/Pa.
virtual double	thermalExpansionCoeff () const
	Return the volumetric thermal expansion coefficient. Units: 1/K.
virtual double	soundSpeed () const
	Return the speed of sound. Units: m/s.
void	setElectricPotential (double v)
	Set the electric potential of this phase (V).
double	electricPotential () const
	Returns the electric potential of this phase (V).
virtual Units	standardConcentrationUnits () const
	Returns the units of the "standard concentration" for this phase.
virtual double	logStandardConc (size_t k=0) const
	Natural logarithm of the standard concentration of the kth species.
virtual void	getLnActivityCoefficients (double *lnac) const
	Get the array of non-dimensional molar-based ln activity coefficients at the current solution temperature, pressure, and solution concentration.
virtual void	getChemPotentials (double *mu) const
	Get the species chemical potentials. Units: J/kmol.
void	getElectrochemPotentials (double *mu) const
	Get the species electrochemical potentials.
virtual void	getPartialMolarEnthalpies (double *hbar) const
	Returns an array of partial molar enthalpies for the species in the mixture.
virtual void	getPartialMolarEntropies (double *sbar) const
	Returns an array of partial molar entropies of the species in the solution.
virtual void	getPartialMolarIntEnergies (double *ubar) const
	Return an array of partial molar internal energies for the species in the mixture.
virtual void	getPartialMolarCp (double *cpbar) const
	Return an array of partial molar heat capacities for the species in the mixture.
virtual void	getPartialMolarVolumes (double *vbar) const
	Return an array of partial molar volumes for the species in the mixture.
virtual void	getIntEnergy_RT_ref (double *urt) const
	Returns the vector of nondimensional internal Energies of the reference state at the current temperature of the solution and the reference pressure for each species.
double	enthalpy_mass () const
	Specific enthalpy. Units: J/kg.
double	intEnergy_mass () const
	Specific internal energy. Units: J/kg.
double	entropy_mass () const
	Specific entropy. Units: J/kg/K.
double	gibbs_mass () const
	Specific Gibbs function. Units: J/kg.
double	cp_mass () const
	Specific heat at constant pressure. Units: J/kg/K.
double	cv_mass () const
	Specific heat at constant volume. Units: J/kg/K.
virtual void	setState_TPX (double t, double p, const double *x)
	Set the temperature (K), pressure (Pa), and mole fractions.
virtual void	setState_TPX (double t, double p, const Composition &x)
	Set the temperature (K), pressure (Pa), and mole fractions.
virtual void	setState_TPX (double t, double p, const string &x)
	Set the temperature (K), pressure (Pa), and mole fractions.
virtual void	setState_TPY (double t, double p, const double *y)
	Set the internally stored temperature (K), pressure (Pa), and mass fractions of the phase.
virtual void	setState_TPY (double t, double p, const Composition &y)
	Set the internally stored temperature (K), pressure (Pa), and mass fractions of the phase.
virtual void	setState_TPY (double t, double p, const string &y)
	Set the internally stored temperature (K), pressure (Pa), and mass fractions of the phase.
virtual void	setState_PX (double p, double *x)
	Set the pressure (Pa) and mole fractions.
virtual void	setState_PY (double p, double *y)
	Set the internally stored pressure (Pa) and mass fractions.
virtual void	setState_HP (double h, double p, double tol=1e-9)
	Set the internally stored specific enthalpy (J/kg) and pressure (Pa) of the phase.
virtual void	setState_UV (double u, double v, double tol=1e-9)
	Set the specific internal energy (J/kg) and specific volume (m^3/kg).
virtual void	setState_SP (double s, double p, double tol=1e-9)
	Set the specific entropy (J/kg/K) and pressure (Pa).
virtual void	setState_SV (double s, double v, double tol=1e-9)
	Set the specific entropy (J/kg/K) and specific volume (m^3/kg).
virtual void	setState_ST (double s, double t, double tol=1e-9)
	Set the specific entropy (J/kg/K) and temperature (K).
virtual void	setState_TV (double t, double v, double tol=1e-9)
	Set the temperature (K) and specific volume (m^3/kg).
virtual void	setState_PV (double p, double v, double tol=1e-9)
	Set the pressure (Pa) and specific volume (m^3/kg).
virtual void	setState_UP (double u, double p, double tol=1e-9)
	Set the specific internal energy (J/kg) and pressure (Pa).
virtual void	setState_VH (double v, double h, double tol=1e-9)
	Set the specific volume (m^3/kg) and the specific enthalpy (J/kg)
virtual void	setState_TH (double t, double h, double tol=1e-9)
	Set the temperature (K) and the specific enthalpy (J/kg)
virtual void	setState_SH (double s, double h, double tol=1e-9)
	Set the specific entropy (J/kg/K) and the specific enthalpy (J/kg)
void	setState_RP (double rho, double p)
	Set the density (kg/m**3) and pressure (Pa) at constant composition.
virtual void	setState_DP (double rho, double p)
	Set the density (kg/m**3) and pressure (Pa) at constant composition.
virtual void	setState_RPX (double rho, double p, const double *x)
	Set the density (kg/m**3), pressure (Pa) and mole fractions.
virtual void	setState_RPX (double rho, double p, const Composition &x)
	Set the density (kg/m**3), pressure (Pa) and mole fractions.
virtual void	setState_RPX (double rho, double p, const string &x)
	Set the density (kg/m**3), pressure (Pa) and mole fractions.
virtual void	setState_RPY (double rho, double p, const double *y)
	Set the density (kg/m**3), pressure (Pa) and mass fractions.
virtual void	setState_RPY (double rho, double p, const Composition &y)
	Set the density (kg/m**3), pressure (Pa) and mass fractions.
virtual void	setState_RPY (double rho, double p, const string &y)
	Set the density (kg/m**3), pressure (Pa) and mass fractions.
void	setMixtureFraction (double mixFrac, const double *fuelComp, const double *oxComp, ThermoBasis basis=ThermoBasis::molar)
	Set the mixture composition according to the mixture fraction = kg fuel / (kg oxidizer + kg fuel)
void	setMixtureFraction (double mixFrac, const string &fuelComp, const string &oxComp, ThermoBasis basis=ThermoBasis::molar)
	Set the mixture composition according to the mixture fraction = kg fuel / (kg oxidizer + kg fuel)
void	setMixtureFraction (double mixFrac, const Composition &fuelComp, const Composition &oxComp, ThermoBasis basis=ThermoBasis::molar)
	Set the mixture composition according to the mixture fraction = kg fuel / (kg oxidizer + kg fuel)
double	mixtureFraction (const double *fuelComp, const double *oxComp, ThermoBasis basis=ThermoBasis::molar, const string &element="Bilger") const
	Compute the mixture fraction = kg fuel / (kg oxidizer + kg fuel) for the current mixture given fuel and oxidizer compositions.
double	mixtureFraction (const string &fuelComp, const string &oxComp, ThermoBasis basis=ThermoBasis::molar, const string &element="Bilger") const
	Compute the mixture fraction = kg fuel / (kg oxidizer + kg fuel) for the current mixture given fuel and oxidizer compositions.
double	mixtureFraction (const Composition &fuelComp, const Composition &oxComp, ThermoBasis basis=ThermoBasis::molar, const string &element="Bilger") const
	Compute the mixture fraction = kg fuel / (kg oxidizer + kg fuel) for the current mixture given fuel and oxidizer compositions.
void	setEquivalenceRatio (double phi, const double *fuelComp, const double *oxComp, ThermoBasis basis=ThermoBasis::molar)
	Set the mixture composition according to the equivalence ratio.
void	setEquivalenceRatio (double phi, const string &fuelComp, const string &oxComp, ThermoBasis basis=ThermoBasis::molar)
	Set the mixture composition according to the equivalence ratio.
void	setEquivalenceRatio (double phi, const Composition &fuelComp, const Composition &oxComp, ThermoBasis basis=ThermoBasis::molar)
	Set the mixture composition according to the equivalence ratio.
double	equivalenceRatio (const double *fuelComp, const double *oxComp, ThermoBasis basis=ThermoBasis::molar) const
	Compute the equivalence ratio for the current mixture given the compositions of fuel and oxidizer.
double	equivalenceRatio (const string &fuelComp, const string &oxComp, ThermoBasis basis=ThermoBasis::molar) const
	Compute the equivalence ratio for the current mixture given the compositions of fuel and oxidizer.
double	equivalenceRatio (const Composition &fuelComp, const Composition &oxComp, ThermoBasis basis=ThermoBasis::molar) const
	Compute the equivalence ratio for the current mixture given the compositions of fuel and oxidizer.
double	stoichAirFuelRatio (const double *fuelComp, const double *oxComp, ThermoBasis basis=ThermoBasis::molar) const
	Compute the stoichiometric air to fuel ratio (kg oxidizer / kg fuel) given fuel and oxidizer compositions.
double	stoichAirFuelRatio (const string &fuelComp, const string &oxComp, ThermoBasis basis=ThermoBasis::molar) const
	Compute the stoichiometric air to fuel ratio (kg oxidizer / kg fuel) given fuel and oxidizer compositions.
double	stoichAirFuelRatio (const Composition &fuelComp, const Composition &oxComp, ThermoBasis basis=ThermoBasis::molar) const
	Compute the stoichiometric air to fuel ratio (kg oxidizer / kg fuel) given fuel and oxidizer compositions.
void	equilibrate (const string &XY, const string &solver="auto", double rtol=1e-9, int max_steps=50000, int max_iter=100, int estimate_equil=0, int log_level=0)
	Equilibrate a ThermoPhase object.
virtual void	setToEquilState (const double *mu_RT)
	This method is used by the ChemEquil equilibrium solver.
virtual bool	compatibleWithMultiPhase () const
	Indicates whether this phase type can be used with class MultiPhase for equilibrium calculations.
virtual double	critTemperature () const
	Critical temperature (K).
virtual double	critPressure () const
	Critical pressure (Pa).
virtual double	critVolume () const
	Critical volume (m3/kmol).
virtual double	critCompressibility () const
	Critical compressibility (unitless).
virtual double	critDensity () const
	Critical density (kg/m3).
virtual double	satTemperature (double p) const
	Return the saturation temperature given the pressure.
virtual double	satPressure (double t)
	Return the saturation pressure given the temperature.
virtual double	vaporFraction () const
	Return the fraction of vapor at the current conditions.
virtual void	setState_Tsat (double t, double x)
	Set the state to a saturated system at a particular temperature.
virtual void	setState_Psat (double p, double x)
	Set the state to a saturated system at a particular pressure.
void	setState_TPQ (double T, double P, double Q)
	Set the temperature, pressure, and vapor fraction (quality).
void	modifySpecies (size_t k, shared_ptr< Species > spec) override
	Modify the thermodynamic data associated with a species.
virtual MultiSpeciesThermo &	speciesThermo (int k=-1)
	Return a changeable reference to the calculation manager for species reference-state thermodynamic properties.
virtual const MultiSpeciesThermo &	speciesThermo (int k=-1) const
void	initThermoFile (const string &inputFile, const string &id)
	Initialize a ThermoPhase object using an input file.
virtual void	setParameters (const AnyMap &phaseNode, const AnyMap &rootNode=AnyMap())
	Set equation of state parameters from an AnyMap phase description.
AnyMap	parameters (bool withInput=true) const
	Returns the parameters of a ThermoPhase object such that an identical one could be reconstructed using the newThermo(AnyMap&) function.
const AnyMap &	input () const
	Access input data associated with the phase description.
AnyMap &	input ()
virtual void	getdlnActCoeffds (const double dTds, const double *const dXds, double *dlnActCoeffds) const
	Get the change in activity coefficients wrt changes in state (temp, mole fraction, etc) along a line in parameter space or along a line in physical space.
virtual void	getdlnActCoeffdlnX_diag (double *dlnActCoeffdlnX_diag) const
	Get the array of ln mole fraction derivatives of the log activity coefficients - diagonal component only.
virtual void	getdlnActCoeffdlnN_diag (double *dlnActCoeffdlnN_diag) const
	Get the array of log species mole number derivatives of the log activity coefficients.
virtual void	getdlnActCoeffdlnN_numderiv (const size_t ld, double *const dlnActCoeffdlnN)
virtual void	reportCSV (std::ofstream &csvFile) const
	returns a summary of the state of the phase to a comma separated file.
Public Member Functions inherited from Phase
	Phase ()=default
	Default constructor.
	Phase (const Phase &)=delete
Phase &	operator= (const Phase &)=delete
virtual bool	isPure () const
	Return whether phase represents a pure (single species) substance.
virtual bool	hasPhaseTransition () const
	Return whether phase represents a substance with phase transitions.
virtual bool	isCompressible () const
	Return whether phase represents a compressible substance.
virtual map< string, size_t >	nativeState () const
	Return a map of properties defining the native state of a substance.
string	nativeMode () const
	Return string acronym representing the native state of a Phase.
virtual vector< string >	fullStates () const
	Return a vector containing full states defining a phase.
virtual vector< string >	partialStates () const
	Return a vector of settable partial property sets within a phase.
virtual size_t	stateSize () const
	Return size of vector defining internal state of the phase.
void	saveState (vector< double > &state) const
	Save the current internal state of the phase.
virtual void	saveState (size_t lenstate, double *state) const
	Write to array 'state' the current internal state.
void	restoreState (const vector< double > &state)
	Restore a state saved on a previous call to saveState.
virtual void	restoreState (size_t lenstate, const double *state)
	Restore the state of the phase from a previously saved state vector.
double	molecularWeight (size_t k) const
	Molecular weight of species k.
void	getMolecularWeights (vector< double > &weights) const
	Copy the vector of molecular weights into vector weights.
void	getMolecularWeights (double *weights) const
	Copy the vector of molecular weights into array weights.
const vector< double > &	molecularWeights () const
	Return a const reference to the internal vector of molecular weights.
const vector< double > &	inverseMolecularWeights () const
	Return a const reference to the internal vector of molecular weights.
void	getCharges (double *charges) const
	Copy the vector of species charges into array charges.
virtual void	setMolesNoTruncate (const double *const N)
	Set the state of the object with moles in [kmol].
double	elementalMassFraction (const size_t m) const
	Elemental mass fraction of element m.
double	elementalMoleFraction (const size_t m) const
	Elemental mole fraction of element m.
const double *	moleFractdivMMW () const
	Returns a const pointer to the start of the moleFraction/MW array.
double	charge (size_t k) const
	Dimensionless electrical charge of a single molecule of species k The charge is normalized by the the magnitude of the electron charge.
double	chargeDensity () const
	Charge density [C/m^3].
size_t	nDim () const
	Returns the number of spatial dimensions (1, 2, or 3)
void	setNDim (size_t ndim)
	Set the number of spatial dimensions (1, 2, or 3).
virtual bool	ready () const
	Returns a bool indicating whether the object is ready for use.
int	stateMFNumber () const
	Return the State Mole Fraction Number.
virtual void	invalidateCache ()
	Invalidate any cached values which are normally updated only when a change in state is detected.
bool	caseSensitiveSpecies () const
	Returns true if case sensitive species names are enforced.
void	setCaseSensitiveSpecies (bool cflag=true)
	Set flag that determines whether case sensitive species are enforced in look-up operations, for example speciesIndex.
vector< double >	getCompositionFromMap (const Composition &comp) const
	Converts a Composition to a vector with entries for each species Species that are not specified are set to zero in the vector.
void	massFractionsToMoleFractions (const double *Y, double *X) const
	Converts a mixture composition from mole fractions to mass fractions.
void	moleFractionsToMassFractions (const double *X, double *Y) const
	Converts a mixture composition from mass fractions to mole fractions.
string	name () const
	Return the name of the phase.
void	setName (const string &nm)
	Sets the string name for the phase.
string	elementName (size_t m) const
	Name of the element with index m.
size_t	elementIndex (const string &name) const
	Return the index of element named 'name'.
const vector< string > &	elementNames () const
	Return a read-only reference to the vector of element names.
double	atomicWeight (size_t m) const
	Atomic weight of element m.
double	entropyElement298 (size_t m) const
	Entropy of the element in its standard state at 298 K and 1 bar.
int	atomicNumber (size_t m) const
	Atomic number of element m.
int	elementType (size_t m) const
	Return the element constraint type Possible types include:
int	changeElementType (int m, int elem_type)
	Change the element type of the mth constraint Reassigns an element type.
const vector< double > &	atomicWeights () const
	Return a read-only reference to the vector of atomic weights.
size_t	nElements () const
	Number of elements.
void	checkElementIndex (size_t m) const
	Check that the specified element index is in range.
void	checkElementArraySize (size_t mm) const
	Check that an array size is at least nElements().
double	nAtoms (size_t k, size_t m) const
	Number of atoms of element m in species k.
void	getAtoms (size_t k, double *atomArray) const
	Get a vector containing the atomic composition of species k.
size_t	speciesIndex (const string &name) const
	Returns the index of a species named 'name' within the Phase object.
string	speciesName (size_t k) const
	Name of the species with index k.
string	speciesSPName (int k) const
	Returns the expanded species name of a species, including the phase name This is guaranteed to be unique within a Cantera problem.
const vector< string > &	speciesNames () const
	Return a const reference to the vector of species names.
size_t	nSpecies () const
	Returns the number of species in the phase.
void	checkSpeciesIndex (size_t k) const
	Check that the specified species index is in range.
void	checkSpeciesArraySize (size_t kk) const
	Check that an array size is at least nSpecies().
void	setMoleFractionsByName (const Composition &xMap)
	Set the species mole fractions by name.
void	setMoleFractionsByName (const string &x)
	Set the mole fractions of a group of species by name.
void	setMassFractionsByName (const Composition &yMap)
	Set the species mass fractions by name.
void	setMassFractionsByName (const string &x)
	Set the species mass fractions by name.
void	setState_TRX (double t, double dens, const double *x)
	Set the internally stored temperature (K), density, and mole fractions.
void	setState_TRX (double t, double dens, const Composition &x)
	Set the internally stored temperature (K), density, and mole fractions.
void	setState_TRY (double t, double dens, const double *y)
	Set the internally stored temperature (K), density, and mass fractions.
void	setState_TRY (double t, double dens, const Composition &y)
	Set the internally stored temperature (K), density, and mass fractions.
void	setState_TNX (double t, double n, const double *x)
	Set the internally stored temperature (K), molar density (kmol/m^3), and mole fractions.
void	setState_TR (double t, double rho)
	Set the internally stored temperature (K) and density (kg/m^3)
void	setState_TD (double t, double rho)
	Set the internally stored temperature (K) and density (kg/m^3)
void	setState_TX (double t, double *x)
	Set the internally stored temperature (K) and mole fractions.
void	setState_TY (double t, double *y)
	Set the internally stored temperature (K) and mass fractions.
void	setState_RX (double rho, double *x)
	Set the density (kg/m^3) and mole fractions.
void	setState_RY (double rho, double *y)
	Set the density (kg/m^3) and mass fractions.
Composition	getMoleFractionsByName (double threshold=0.0) const
	Get the mole fractions by name.
double	moleFraction (size_t k) const
	Return the mole fraction of a single species.
double	moleFraction (const string &name) const
	Return the mole fraction of a single species.
Composition	getMassFractionsByName (double threshold=0.0) const
	Get the mass fractions by name.
double	massFraction (size_t k) const
	Return the mass fraction of a single species.
double	massFraction (const string &name) const
	Return the mass fraction of a single species.
void	getMoleFractions (double *const x) const
	Get the species mole fraction vector.
virtual void	setMoleFractions (const double *const x)
	Set the mole fractions to the specified values.
virtual void	setMoleFractions_NoNorm (const double *const x)
	Set the mole fractions to the specified values without normalizing.
void	getMassFractions (double *const y) const
	Get the species mass fractions.
const double *	massFractions () const
	Return a const pointer to the mass fraction array.
virtual void	setMassFractions (const double *const y)
	Set the mass fractions to the specified values and normalize them.
virtual void	setMassFractions_NoNorm (const double *const y)
	Set the mass fractions to the specified values without normalizing.
virtual void	getConcentrations (double *const c) const
	Get the species concentrations (kmol/m^3).
virtual double	concentration (const size_t k) const
	Concentration of species k.
virtual void	setConcentrations (const double *const conc)
	Set the concentrations to the specified values within the phase.
virtual void	setConcentrationsNoNorm (const double *const conc)
	Set the concentrations without ignoring negative concentrations.
double	temperature () const
	Temperature (K).
virtual double	electronTemperature () const
	Electron Temperature (K)
virtual double	density () const
	Density (kg/m^3).
virtual double	molarDensity () const
	Molar density (kmol/m^3).
virtual double	molarVolume () const
	Molar volume (m^3/kmol).
virtual void	setDensity (const double density_)
	Set the internally stored density (kg/m^3) of the phase.
virtual void	setMolarDensity (const double molarDensity)
	Set the internally stored molar density (kmol/m^3) of the phase.
virtual void	setElectronTemperature (double etemp)
	Set the internally stored electron temperature of the phase (K).
double	mean_X (const double *const Q) const
	Evaluate the mole-fraction-weighted mean of an array Q.
double	mean_X (const vector< double > &Q) const
	Evaluate the mole-fraction-weighted mean of an array Q.
double	meanMolecularWeight () const
	The mean molecular weight. Units: (kg/kmol)
double	sum_xlogx () const
	Evaluate \( \sum_k X_k \ln X_k \).
size_t	addElement (const string &symbol, double weight=-12345.0, int atomicNumber=0, double entropy298=ENTROPY298_UNKNOWN, int elem_type=CT_ELEM_TYPE_ABSPOS)
	Add an element.
void	addSpeciesAlias (const string &name, const string &alias)
	Add a species alias (that is, a user-defined alternative species name).
virtual vector< string >	findIsomers (const Composition &compMap) const
	Return a vector with isomers names matching a given composition map.
virtual vector< string >	findIsomers (const string &comp) const
	Return a vector with isomers names matching a given composition string.
shared_ptr< Species >	species (const string &name) const
	Return the Species object for the named species.
shared_ptr< Species >	species (size_t k) const
	Return the Species object for species whose index is k.
void	ignoreUndefinedElements ()
	Set behavior when adding a species containing undefined elements to just skip the species.
void	addUndefinedElements ()
	Set behavior when adding a species containing undefined elements to add those elements to the phase.
void	throwUndefinedElements ()
	Set the behavior when adding a species containing undefined elements to throw an exception.

Protected Member Functions
void	getCsvReportData (vector< string > &names, vector< vector< double > > &data) const override
	Fills names and data with the column names and species thermo properties to be included in the output of the reportCSV method.
virtual void	getUnscaledMolalityActivityCoefficients (double *acMolality) const
	Get the array of unscaled non-dimensional molality based activity coefficients at the current solution temperature, pressure, and solution concentration.
virtual void	applyphScale (double *acMolality) const
	Apply the current phScale to a set of activity Coefficients or activities.
Protected Member Functions inherited from VPStandardStateTP
virtual void	calcDensity ()
	Calculate the density of the mixture using the partial molar volumes and mole fractions as input.
virtual void	_updateStandardStateThermo () const
	Updates the standard state thermodynamic functions at the current T and P of the solution.
void	invalidateCache () override
	Invalidate any cached values which are normally updated only when a change in state is detected.
const vector< double > &	Gibbs_RT_ref () const
Protected Member Functions inherited from ThermoPhase
virtual void	getParameters (AnyMap &phaseNode) const
	Store the parameters of a ThermoPhase object such that an identical one could be reconstructed using the newThermo(AnyMap&) function.
virtual void	getCsvReportData (vector< string > &names, vector< vector< double > > &data) const
	Fills names and data with the column names and species thermo properties to be included in the output of the reportCSV method.
Protected Member Functions inherited from Phase
void	assertCompressible (const string &setter) const
	Ensure that phase is compressible.
void	assignDensity (const double density_)
	Set the internally stored constant density (kg/m^3) of the phase.
void	setMolecularWeight (const int k, const double mw)
	Set the molecular weight of a single species to a given value.
virtual void	compositionChanged ()
	Apply changes to the state which are needed after the composition changes.

Protected Attributes
int	m_pHScalingType = PHSCALE_PITZER
	Scaling to be used for output of single-ion species activity coefficients.
size_t	m_indexCLM = npos
	Index of the phScale species.
double	m_weightSolvent = 18.01528
	Molecular weight of the Solvent.
double	m_xmolSolventMIN = 0.01
	In any molality implementation, it makes sense to have a minimum solvent mole fraction requirement, since the implementation becomes singular in the xmolSolvent=0 limit.
double	m_Mnaught = 18.01528E-3
	This is the multiplication factor that goes inside log expressions involving the molalities of species.
vector< double >	m_molalities
	Current value of the molalities of the species in the phase.
Protected Attributes inherited from VPStandardStateTP
double	m_Pcurrent = OneAtm
	Current value of the pressure - state variable.
double	m_minTemp = 0.0
	The minimum temperature at which data for all species is valid.
double	m_maxTemp = BigNumber
	The maximum temperature at which data for all species is valid.
double	m_Tlast_ss = -1.0
	The last temperature at which the standard state thermodynamic properties were calculated at.
double	m_Plast_ss = -1.0
	The last pressure at which the Standard State thermodynamic properties were calculated at.
vector< unique_ptr< PDSS > >	m_PDSS_storage
	Storage for the PDSS objects for the species.
vector< double >	m_h0_RT
	Vector containing the species reference enthalpies at T = m_tlast and P = p_ref.
vector< double >	m_cp0_R
	Vector containing the species reference constant pressure heat capacities at T = m_tlast and P = p_ref.
vector< double >	m_g0_RT
	Vector containing the species reference Gibbs functions at T = m_tlast and P = p_ref.
vector< double >	m_s0_R
	Vector containing the species reference entropies at T = m_tlast and P = p_ref.
vector< double >	m_V0
	Vector containing the species reference molar volumes.
vector< double >	m_hss_RT
	Vector containing the species Standard State enthalpies at T = m_tlast and P = m_plast.
vector< double >	m_cpss_R
	Vector containing the species Standard State constant pressure heat capacities at T = m_tlast and P = m_plast.
vector< double >	m_gss_RT
	Vector containing the species Standard State Gibbs functions at T = m_tlast and P = m_plast.
vector< double >	m_sss_R
	Vector containing the species Standard State entropies at T = m_tlast and P = m_plast.
vector< double >	m_Vss
	Vector containing the species standard state volumes at T = m_tlast and P = m_plast.
Protected Attributes inherited from ThermoPhase
MultiSpeciesThermo	m_spthermo
	Pointer to the calculation manager for species reference-state thermodynamic properties.
AnyMap	m_input
	Data supplied via setParameters.
double	m_phi = 0.0
	Stored value of the electric potential for this phase. Units are Volts.
bool	m_chargeNeutralityNecessary = false
	Boolean indicating whether a charge neutrality condition is a necessity.
int	m_ssConvention = cSS_CONVENTION_TEMPERATURE
	Contains the standard state convention.
double	m_tlast = 0.0
	last value of the temperature processed by reference state
Protected Attributes inherited from Phase
ValueCache	m_cache
	Cached for saved calculations within each ThermoPhase.
size_t	m_kk = 0
	Number of species in the phase.
size_t	m_ndim = 3
	Dimensionality of the phase.
vector< double >	m_speciesComp
	Atomic composition of the species.
vector< double >	m_speciesCharge
	Vector of species charges. length m_kk.
map< string, shared_ptr< Species > >	m_species
UndefElement::behavior	m_undefinedElementBehavior = UndefElement::add
	Flag determining behavior when adding species with an undefined element.
bool	m_caseSensitiveSpecies = false
	Flag determining whether case sensitive species names are enforced.

Private Member Functions
size_t	findCLMIndex () const
	Returns the index of the Cl- species.

Constructor & Destructor Documentation

MolalityVPSSTP()

MolalityVPSSTP

(

)

Default Constructor.

This doesn't do much more than initialize constants with default values for water at 25C. Water molecular weight comes from the default elements definitions. It actually differs slightly from the IAPWS95 value of 18.015268. However, density conservation and therefore element conservation is the more important principle to follow.

Definition at line 21 of file MolalityVPSSTP.cpp.

Member Function Documentation

phaseOfMatter()

string phaseOfMatter ( ) const

inlineoverridevirtual

String indicating the mechanical phase of the matter in this Phase.

All derived phases from MolalityVPSSTP always represent liquids.

Reimplemented from ThermoPhase.

Definition at line 246 of file MolalityVPSSTP.h.

setpHScale()

void setpHScale

(

const int

pHscaleType

)

Set the pH scale, which determines the scale for single-ion activity coefficients.

Single ion activity coefficients are not unique in terms of the representing actual measurable quantities.

Parameters

pHscaleType

Integer representing the pHscale

Definition at line 31 of file MolalityVPSSTP.cpp.

pHScale()

int pHScale

(

)

const

Reports the pH scale, which determines the scale for single-ion activity coefficients.

Single ion activity coefficients are not unique in terms of the representing actual measurable quantities.

Returns

the pHscale type

Definition at line 40 of file MolalityVPSSTP.cpp.

setMoleFSolventMin()

void setMoleFSolventMin

(

double

xmolSolventMIN

)

Sets the minimum mole fraction in the molality formulation.

Note the molality formulation is singular in the limit that the solvent mole fraction goes to zero. Numerically, how this limit is treated and resolved is an ongoing issue within Cantera. The minimum mole fraction must be in the range 0 to 0.9.

Parameters

xmolSolventMIN

Input double containing the minimum mole fraction

Definition at line 45 of file MolalityVPSSTP.cpp.

moleFSolventMin()

double moleFSolventMin

(

)

const

Returns the minimum mole fraction in the molality formulation.

Definition at line 55 of file MolalityVPSSTP.cpp.

calcMolalities()

void calcMolalities

(

)

const

Calculates the molality of all species and stores the result internally.

We calculate the vector of molalities of the species in the phase and store the result internally:

\[ m_i = \frac{X_i}{1000 * M_o * X_{o,p}} \]

where

• \( M_o \) is the molecular weight of the solvent
• \( X_o \) is the mole fraction of the solvent
• \( X_i \) is the mole fraction of the solute.
• \( X_{o,p} = \max (X_{o}^{min}, X_o) \)
• \( X_{o}^{min} \) = minimum mole fraction of solvent allowed in the denominator.

Definition at line 60 of file MolalityVPSSTP.cpp.

getMolalities()

void getMolalities

(

double *const

molal

)

const

This function will return the molalities of the species.

We calculate the vector of molalities of the species in the phase

\[ m_i = \frac{X_i}{1000 * M_o * X_{o,p}} \]

where

• \( M_o \) is the molecular weight of the solvent
• \( X_o \) is the mole fraction of the solvent
• \( X_i \) is the mole fraction of the solute.
• \( X_{o,p} = \max (X_{o}^{min}, X_o) \)
• \( X_{o}^{min} \) = minimum mole fraction of solvent allowed in the denominator.

Parameters

molal

Output vector of molalities. Length: m_kk.

Definition at line 70 of file MolalityVPSSTP.cpp.

setMolalities()

void setMolalities

(

const double *const

molal

)

Set the molalities of the solutes in a phase.

Note, the entry for the solvent is not used. We are supplied with the molalities of all of the solute species. We then calculate the mole fractions of all species and update the ThermoPhase object.

\[ m_i = \frac{X_i}{M_o/1000 * X_{o,p}} \]

where

• \( M_o \) is the molecular weight of the solvent
• \( X_o \) is the mole fraction of the solvent
• \( X_i \) is the mole fraction of the solute.
• \( X_{o,p} = \max(X_o^{min}, X_o) \)
• \( X_o^{min} \) = minimum mole fraction of solvent allowed in the denominator.

The formulas for calculating mole fractions are

\[ L^{sum} = \frac{1}{\tilde{M}_o X_o} = \frac{1}{\tilde{M}_o} + \sum_{i\ne o} m_i \]

Then,

\[ X_o = \frac{1}{\tilde{M}_o L^{sum}} \]

\[ X_i = \frac{m_i}{L^{sum}} \]

It is currently an error if the solvent mole fraction is attempted to be set to a value lower than \( X_o^{min} \).

Parameters

molal

Input vector of molalities. Length: m_kk.

Definition at line 78 of file MolalityVPSSTP.cpp.

setMolalitiesByName() [1/2]

void setMolalitiesByName

(

const Composition &

xMap

)

Set the molalities of a phase.

Set the molalities of the solutes in a phase. Note, the entry for the solvent is not used.

Parameters

xMap	Composition Map containing the molalities.

Definition at line 105 of file MolalityVPSSTP.cpp.

setMolalitiesByName() [2/2]

void setMolalitiesByName

(

const string &

name

)

Set the molalities of a phase.

Set the molalities of the solutes in a phase. Note, the entry for the solvent is not used.

Parameters

name	String containing the information for a composition map.

Definition at line 173 of file MolalityVPSSTP.cpp.

activityConvention()

int activityConvention ( ) const

overridevirtual

We set the convention to molality here.

Reimplemented from ThermoPhase.

Definition at line 181 of file MolalityVPSSTP.cpp.

getActivityConcentrations()

void getActivityConcentrations ( double *  c ) const

overridevirtual

This method returns an array of generalized concentrations.

\( C^a_k \) are defined such that \( a_k = C^a_k / C^0_k, \) where \( C^0_k \) is a standard concentration defined below and \( a_k \) are activities used in the thermodynamic functions. These activity (or generalized) concentrations are used by kinetics manager classes to compute the forward and reverse rates of elementary reactions. Note that they may or may not have units of concentration — they might be partial pressures, mole fractions, or surface coverages, for example.

Parameters

c	Output array of generalized concentrations. The units depend upon the implementation of the reaction rate expressions within the phase.

Reimplemented from ThermoPhase.

Definition at line 186 of file MolalityVPSSTP.cpp.

standardConcentration()

double standardConcentration ( size_t  k = 0 ) const

overridevirtual

Return the standard concentration for the kth species.

The standard concentration \( C^0_k \) used to normalize the activity (that is, generalized) concentration. In many cases, this quantity will be the same for all species in a phase - for example, for an ideal gas \( C^0_k = P/\hat R T \). For this reason, this method returns a single value, instead of an array. However, for phases in which the standard concentration is species-specific (such as surface species of different sizes), this method may be called with an optional parameter indicating the species.

Parameters

k	Optional parameter indicating the species. The default is to assume this refers to species 0.

Returns

Returns the standard concentration. The units are by definition dependent on the ThermoPhase and kinetics manager representation.

Reimplemented from ThermoPhase.

Definition at line 191 of file MolalityVPSSTP.cpp.

getActivities()

void getActivities ( double *  ac ) const

overridevirtual

Get the array of non-dimensional activities (molality based for this class and classes that derive from it) at the current solution temperature, pressure, and solution concentration.

All standard state properties for molality-based phases are evaluated consistent with the molality scale. Therefore, this function must return molality-based activities.

\[ a_i^\triangle = \gamma_k^{\triangle} \frac{m_k}{m^\triangle} \]

This function must be implemented in derived classes.

Parameters

ac	Output vector of molality-based activities. Length: m_kk.

Reimplemented from ThermoPhase.

Definition at line 196 of file MolalityVPSSTP.cpp.

getActivityCoefficients()

void getActivityCoefficients ( double *  ac ) const

overridevirtual

Get the array of non-dimensional activity coefficients at the current solution temperature, pressure, and solution concentration.

These are mole-fraction based activity coefficients. In this object, their calculation is based on translating the values of the molality-based activity coefficients. See Denbigh p. 278 [5] for a thorough discussion.

The molar-based activity coefficients \( \gamma_k \) may be calculated from the molality-based activity coefficients, \( \gamma_k^\triangle \) by the following formula.

\[ \gamma_k = \frac{\gamma_k^\triangle}{X_o} \]

For purposes of establishing a convention, the molar activity coefficient of the solvent is set equal to the molality-based activity coefficient of the solvent:

\[ \gamma_o = \gamma_o^\triangle \]

Derived classes don't need to overload this function. This function is handled at this level.

Parameters

ac	Output vector containing the mole-fraction based activity coefficients. length: m_kk.

Reimplemented from ThermoPhase.

Definition at line 201 of file MolalityVPSSTP.cpp.

getMolalityActivityCoefficients()

void getMolalityActivityCoefficients ( double *  acMolality ) const

virtual

Get the array of non-dimensional molality based activity coefficients at the current solution temperature, pressure, and solution concentration.

See Denbigh p. 278 [5] for a thorough discussion. This method must be overridden in classes which derive from MolalityVPSSTP. This function takes over from the molar-based activity coefficient calculation, getActivityCoefficients(), in derived classes.

These molality based activity coefficients are scaled according to the current pH scale. See the Eq3/6 manual for details.

Activity coefficients for species k may be altered between scales s1 to s2 using the following formula

\[ \ln(\gamma_k^{s2}) = \ln(\gamma_k^{s1}) + \frac{z_k}{z_j} \left( \ln(\gamma_j^{s2}) - \ln(\gamma_j^{s1}) \right) \]

where j is any one species. For the NBS scale, j is equal to the Cl- species and

\[ \ln(\gamma_{Cl-}^{s2}) = \frac{-A_{\phi} \sqrt{I}}{1.0 + 1.5 \sqrt{I}} \]

Parameters

acMolality

Output vector containing the molality based activity coefficients. length: m_kk.

Reimplemented in DebyeHuckel, and IdealMolalSoln.

Definition at line 210 of file MolalityVPSSTP.cpp.

osmoticCoefficient()

double osmoticCoefficient ( ) const

virtual

Calculate the osmotic coefficient.

\[ \phi = \frac{- \ln(a_o)}{\tilde{M}_o \sum_{i \ne o} m_i} \]

Note there are a few of definitions of the osmotic coefficient floating around. We use the one defined in (Activity Coefficients in Electrolyte Solutions, K. S. Pitzer CRC Press, Boca Raton, 1991, p. 85, Eqn. 28). This definition is most clearly related to theoretical calculation.

units = dimensionless

Definition at line 216 of file MolalityVPSSTP.cpp.

addSpecies()

bool addSpecies ( shared_ptr< Species >  spec )

overridevirtual

Add a Species to this Phase.

Returns true if the species was successfully added, or false if the species was ignored.

Derived classes which need to size arrays according to the number of species should overload this method. The derived class implementation should call the base class method, and, if this returns true (indicating that the species has been added), adjust their array sizes accordingly.

See also

ignoreUndefinedElements addUndefinedElements throwUndefinedElements

Reimplemented from Phase.

Definition at line 343 of file MolalityVPSSTP.cpp.

initThermo()

void initThermo ( )

overridevirtual

Initialize the ThermoPhase object after all species have been set up.

This method is provided to allow subclasses to perform any initialization required after all species have been added. For example, it might be used to resize internal work arrays that must have an entry for each species. The base class implementation does nothing, and subclasses that do not require initialization do not need to overload this method. Derived classes which do override this function should call their parent class's implementation of this function as their last action.

When importing from an AnyMap phase description (or from a YAML file), setupPhase() adds all the species, stores the input data in m_input, and then calls this method to set model parameters from the data stored in m_input.

Reimplemented from ThermoPhase.

Definition at line 269 of file MolalityVPSSTP.cpp.

setState_TPM() [1/3]

void setState_TPM	(	double	t,
		double	p,
		const double *const	molalities
	)

Set the temperature (K), pressure (Pa), and molalities (gmol kg-1) of the solutes.

Parameters

t	Temperature (K)
p	Pressure (Pa)
molalities	Input vector of molalities of the solutes. Length: m_kk.

Definition at line 234 of file MolalityVPSSTP.cpp.

setState_TPM() [2/3]

void setState_TPM	(	double	t,
		double	p,
		const Composition &	m
	)

Set the temperature (K), pressure (Pa), and molalities.

Parameters

t	Temperature (K)
p	Pressure (Pa)
m	Composition containing the molalities

Definition at line 240 of file MolalityVPSSTP.cpp.

setState_TPM() [3/3]

void setState_TPM	(	double	t,
		double	p,
		const string &	m
	)

Set the temperature (K), pressure (Pa), and molalities.

Parameters

t	Temperature (K)
p	Pressure (Pa)
m	String which gets translated into a composition map for the molalities of the solutes.

Definition at line 246 of file MolalityVPSSTP.cpp.

setState()

void setState ( const AnyMap &  state )

overridevirtual

Set the state using an AnyMap containing any combination of properties supported by the thermodynamic model.

Accepted keys are:

• X (mole fractions)
• Y (mass fractions)
• T or temperature
• P or pressure [Pa]
• H or enthalpy [J/kg]
• U or internal-energy [J/kg]
• S or entropy [J/kg/K]
• V or specific-volume [m^3/kg]
• D or density [kg/m^3]

Composition can be specified as either an AnyMap of species names to values or as a composition string. All other values can be given as floating point values in Cantera's default units, or as strings with the units specified, which will be converted using the Units class.

If no thermodynamic property pair is given, or only one of temperature or pressure is given, then 298.15 K and 101325 Pa will be used as necessary to fully set the state.

Additionally uses the keys molalities or M to set the molalities.

Reimplemented from ThermoPhase.

Definition at line 252 of file MolalityVPSSTP.cpp.

getdlnActCoeffdlnN()

void getdlnActCoeffdlnN ( const size_t  ld, double *const  dlnActCoeffdlnN  )

inlineoverridevirtual

Get the array of derivatives of the log activity coefficients with respect to the log of the species mole numbers.

Implementations should take the derivative of the logarithm of the activity coefficient with respect to a species log mole number (with all other species mole numbers held constant). The default treatment in the ThermoPhase object is to set this vector to zero.

units = 1 / kmol

dlnActCoeffdlnN[ ld * k + m] will contain the derivative of log act_coeff for the m-th species with respect to the number of moles of the k-th species.

\[ \frac{d \ln(\gamma_m) }{d \ln( n_k ) }\Bigg|_{n_i} \]

When implemented, this method is used within the VCS equilibrium solver to calculate the Jacobian elements, which accelerates convergence of the algorithm.

Parameters

ld	Number of rows in the matrix
dlnActCoeffdlnN	Output vector of derivatives of the log Activity Coefficients. length = m_kk * m_kk

Reimplemented from ThermoPhase.

Definition at line 535 of file MolalityVPSSTP.h.

report()

string report ( bool  show_thermo = true, double  threshold = 1e-14  ) const

overridevirtual

returns a summary of the state of the phase as a string

Parameters

show_thermo	If true, extra information is printed out about the thermodynamic state of the system.
threshold	Show information about species with mole fractions greater than threshold.

Reimplemented from ThermoPhase.

Definition at line 357 of file MolalityVPSSTP.cpp.

getCsvReportData()

void getCsvReportData ( vector< string > &  names, vector< vector< double > > &  data  ) const

overrideprotectedvirtual

Fills names and data with the column names and species thermo properties to be included in the output of the reportCSV method.

Deprecated:

To be removed after Cantera 3.0.

Reimplemented from ThermoPhase.

Definition at line 465 of file MolalityVPSSTP.cpp.

getUnscaledMolalityActivityCoefficients()

void getUnscaledMolalityActivityCoefficients ( double *  acMolality ) const

protectedvirtual

Get the array of unscaled non-dimensional molality based activity coefficients at the current solution temperature, pressure, and solution concentration.

See Denbigh p. 278 [5] for a thorough discussion. This method must be overridden in classes which derive from MolalityVPSSTP. This function takes over from the molar-based activity coefficient calculation, getActivityCoefficients(), in derived classes.

Parameters

acMolality

Output vector containing the molality based activity coefficients. length: m_kk.

Reimplemented in HMWSoln.

Definition at line 277 of file MolalityVPSSTP.cpp.

applyphScale()

void applyphScale ( double *  acMolality ) const

protectedvirtual

Apply the current phScale to a set of activity Coefficients or activities.

See the Eq3/6 Manual for a thorough discussion.

Parameters

acMolality

input/Output vector containing the molality based activity coefficients. length: m_kk.

Reimplemented in HMWSoln.

Definition at line 282 of file MolalityVPSSTP.cpp.

findCLMIndex()

size_t findCLMIndex ( ) const

private

Returns the index of the Cl- species.

The Cl- species is special in the sense that its single ion molality- based activity coefficient is used in the specification of the pH scale for single ions. Therefore, we need to know what species index is Cl-. If the species isn't in the species list then this routine returns -1, and we can't use the NBS pH scale.

Right now we use a restrictive interpretation. The species must be named "Cl-". It must consist of exactly one Cl and one E atom.

Definition at line 287 of file MolalityVPSSTP.cpp.

Member Data Documentation

m_pHScalingType

int m_pHScalingType = PHSCALE_PITZER

protected

Scaling to be used for output of single-ion species activity coefficients.

Index of the species to be used in the single-ion scaling law. This is the identity of the Cl- species for the PHSCALE_NBS scaling. Either PHSCALE_PITZER or PHSCALE_NBS

Definition at line 591 of file MolalityVPSSTP.h.

m_indexCLM

size_t m_indexCLM = npos

protected

Index of the phScale species.

Index of the species to be used in the single-ion scaling law. This is the identity of the Cl- species for the PHSCALE_NBS scaling

Definition at line 598 of file MolalityVPSSTP.h.

m_weightSolvent

double m_weightSolvent = 18.01528

protected

Molecular weight of the Solvent.

Definition at line 601 of file MolalityVPSSTP.h.

m_xmolSolventMIN

double m_xmolSolventMIN = 0.01

protected

In any molality implementation, it makes sense to have a minimum solvent mole fraction requirement, since the implementation becomes singular in the xmolSolvent=0 limit.

The default is to set it to 0.01. We then modify the molality definition to ensure that molal_solvent = 0 when xmol_solvent = 0.

Definition at line 610 of file MolalityVPSSTP.h.

m_Mnaught

double m_Mnaught = 18.01528E-3

protected

This is the multiplication factor that goes inside log expressions involving the molalities of species.

It's equal to Wt_0 / 1000, where Wt_0 = weight of solvent (kg/kmol)

Definition at line 615 of file MolalityVPSSTP.h.

m_molalities

vector<double> m_molalities

mutableprotected

Current value of the molalities of the species in the phase.

Note this vector is a mutable quantity. units are (kg/kmol)

Definition at line 619 of file MolalityVPSSTP.h.

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The documentation for this class was generated from the following files:

• MolalityVPSSTP.h
• MolalityVPSSTP.cpp