cantera/include/cantera/thermo/FixedChemPotSSTP.h

388 lines
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C++

/**
* @file FixedChemPotSSTP.h
* Header file for the FixedChemPotSSTP class, which represents a fixed-composition
* incompressible substance with a constant chemical potential (see \ref thermoprops and
* class \link Cantera::FixedChemPotSSTP FixedChemPotSSTP\endlink)
*/
// This file is part of Cantera. See License.txt in the top-level directory or
// at https://cantera.org/license.txt for license and copyright information.
#ifndef CT_FIXEDCHEMPOTSSTP_H
#define CT_FIXEDCHEMPOTSSTP_H
#include "SingleSpeciesTP.h"
namespace Cantera
{
//! Class FixedChemPotSSTP represents a stoichiometric (fixed composition)
//! incompressible substance.
/*!
* This class internally changes the independent degree of freedom from density
* to pressure. This is necessary because the phase is incompressible. It uses a
* zero volume approximation.
*
* ## Specification of Species Standard State Properties
*
* This class inherits from SingleSpeciesTP. It uses a single value for the
* chemical potential which is assumed to be constant with respect to
* temperature and pressure.
*
* The reference state thermodynamics is inherited from SingleSpeciesTP.
* However, it's only used to set the initial chemical potential to the value of
* the chemical potential at the starting conditions. Thereafter, it is ignored.
*
* For a zero volume material, the internal energy and the enthalpy are equal to
* the chemical potential. The entropy, the heat capacity, and the molar volume
* are equal to zero.
*
* ## Specification of Solution Thermodynamic Properties
*
* All solution properties are obtained from the standard state species
* functions, since there is only one species in the phase.
*
* ## Application within Kinetics Managers
*
* The standard concentration is equal to 1.0. This means that the kinetics
* operator works on an (activities basis). Since this is a stoichiometric
* substance, this means that the concentration of this phase drops out of
* kinetics expressions.
*
* An example of a reaction using this is a sticking coefficient reaction of a
* substance in an ideal gas phase on a surface with a bulk phase species in
* this phase. In this case, the rate of progress for this reaction, \f$ R_s
* \f$, may be expressed via the following equation:
* \f[
* R_s = k_s C_{gas}
* \f]
* where the units for \f$ R_s \f$ are kmol m-2 s-1. \f$ C_{gas} \f$ has units
* of kmol m-3. Therefore, the kinetic rate constant, \f$ k_s \f$, has units of
* m s-1. Nowhere does the concentration of the bulk phase appear in the rate
* constant expression, since it's a stoichiometric phase, and the activity is
* always equal to 1.0.
*
* ## Instantiation of the Class
*
* This phase may be instantiated by calling the default ThermoFactory routine
* for %Cantera. This new FixedChemPotSSTP object must then have a standalone
* XML file description an example of which is given below.
*
* It may also be created by the following code snippets. The code includes the
* special member function setChemicalPotential( chempot), which sets the
* chemical potential to a specific value in J / kmol.
*
* @code
* XML_Node *xm = get_XML_NameID("phase", iFile + "#Li(Fixed)", 0);
* FixedChemPotSSTP *LiFixed = new FixedChemPotSSTP(*xm);
* // Set the chemical potential to -2.3E7 J/kmol
* LiFixed->setChemicalPotential(-2.3E7.)
* @endcode
*
* or by the following call to importPhase():
*
* @code
* XML_Node *xm = get_XML_NameID("phase", iFile + "#NaCl(S)", 0);
* FixedChemPotSSTP solid;
* importPhase(*xm, &solid);
* @endcode
*
* The phase may also be created by a special constructor so that element
* potentials may be set. The constructor takes the name of the element and
* the value of the element chemical potential. An example is given below.
*
* @code
* FixedChemPotSSTP *LiFixed = new FixedChemPotSSTP("Li", -2.3E7);
* @endcode
*
* ## XML Example
*
* The phase model name for this is called FixedChemPot. It must be supplied
* as the model attribute of the thermo XML element entry.
*
* @code
* <?xml version="1.0"?>
* <ctml>
* <validate reactions="yes" species="yes"/>
*
* <!-- phase NaCl(S) -->
* <phase dim="3" id="LiFixed">
* <elementArray datasrc="elements.xml">
* Li
* </elementArray>
* <speciesArray datasrc="#species_Li(Fixed)">
* LiFixed
* </speciesArray>
* <thermo model="FixedChemPot">
* <chemicalPotential units="J/kmol"> -2.3E7 </chemicalPotential>
* </thermo>
* <transport model="None"/>
* <kinetics model="none"/>
* </phase>
*
* <!-- species definitions -->
* <speciesData id="species_Li(Fixed)">
* <species name="LiFixed">
* <atomArray> Li:1 </atomArray>
* <thermo>
* <Shomate Pref="1 bar" Tmax="1075.0" Tmin="250.0">
* <floatArray size="7">
* 50.72389, 6.672267, -2.517167,
* 10.15934, -0.200675, -427.2115,
* 130.3973
* </floatArray>
* </Shomate>
* </thermo>
* </species>
* </speciesData>
* </ctml>
* @endcode
*
* The model attribute, "FixedChemPot", on the thermo element
* identifies the phase as being a FixedChemPotSSTP object.
*
* @ingroup thermoprops
*/
class FixedChemPotSSTP : public SingleSpeciesTP
{
public:
//! Default constructor for the FixedChemPotSSTP class
FixedChemPotSSTP();
//! Construct and initialize a FixedChemPotSSTP ThermoPhase object
//! directly from an ASCII input file
/*!
* @param infile name of the input file
* @param id name of the phase id in the file.
* If this is blank, the first phase in the file is used.
*/
FixedChemPotSSTP(const std::string& infile, const std::string& id = "");
//! Construct and initialize a FixedChemPotSSTP ThermoPhase object
//! directly from an XML database
/*!
* @param phaseRef XML node pointing to a FixedChemPotSSTP description
* @param id Id of the phase.
*/
FixedChemPotSSTP(XML_Node& phaseRef, const std::string& id = "");
//! Special constructor for the FixecChemPotSSTP class setting an element
//! chemical potential directly
/*!
* This will create a FixedChemPotSSTP consisting of a single species with the
* stoichiometry of one of the specified atom. It will have a chemical potential
* that is given by the second argument.
*
* @param Ename String name of the element
* @param chemPot Value of the chemical potential of that element (J/kmol)
*/
FixedChemPotSSTP(const std::string& Ename, doublereal chemPot);
virtual std::string type() const {
return "FixedChemPot";
}
//! @}
//! @name Mechanical Equation of State
//! @{
//! Report the Pressure. Units: Pa.
/*!
* For an incompressible substance, the density is independent of pressure.
* This method simply returns the stored pressure value.
*/
virtual doublereal pressure() const;
//! Set the pressure at constant temperature. Units: Pa.
/*!
* For an incompressible substance, the density is independent of pressure.
* Therefore, this method only stores the specified pressure value. It does
* not modify the density.
*
* @param p Pressure (units - Pa)
*/
virtual void setPressure(doublereal p);
virtual doublereal isothermalCompressibility() const;
virtual doublereal thermalExpansionCoeff() const;
/**
* @}
* @name Activities, Standard States, and Activity Concentrations
*
* This section is largely handled by parent classes, since there
* is only one species. Therefore, the activity is equal to one.
* @{
*/
virtual Units standardConcentrationUnits() const;
//! @copydoc ThermoPhase::getActivityConcentrations
/*!
* For a stoichiometric substance, there is only one species, and the
* generalized concentration is 1.0.
*/
virtual void getActivityConcentrations(doublereal* c) const;
//! Return the standard concentration for the kth species
/*!
* The standard concentration \f$ C^0_k \f$ used to normalize the activity
* (i.e., generalized) concentration. This phase assumes that the kinetics
* operator works on an dimensionless basis. Thus, the standard
* concentration is equal to 1.0.
*
* @param k Optional parameter indicating the species. The default is to
* assume this refers to species 0.
* @return
* Returns The standard Concentration as 1.0
*/
virtual doublereal standardConcentration(size_t k=0) const;
virtual doublereal logStandardConc(size_t k=0) const;
//! 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.
/*!
* For a stoichiometric substance, there is no activity term in the chemical
* potential expression, and therefore the standard chemical potential and
* the chemical potential are both equal to the molar Gibbs function.
*
* These are the standard state chemical potentials \f$ \mu^0_k(T,P) \f$.
* The values are evaluated at the current temperature and pressure of the
* solution
*
* @param mu0 Output vector of chemical potentials. Length: m_kk.
*/
virtual void getStandardChemPotentials(doublereal* mu0) const;
//@}
/// @name Partial Molar Properties of the Solution
/// These properties are handled by the parent class, SingleSpeciesTP
//@{
//! Get the species partial molar volumes. Units: m^3/kmol.
/*!
* This is the phase molar volume. \f$ V(T,P) = V_o(T,P) \f$.
*
* set to zero.
*
* @param vbar On return, contains the molar volume of the single species
* and the phase. Units are m^3 / kmol. Length = 1
*/
virtual void getPartialMolarVolumes(doublereal* vbar) const;
//@}
/// @name Properties of the Standard State of the Species in the Solution
//@{
virtual void getEnthalpy_RT(doublereal* hrt) const;
virtual void getEntropy_R(doublereal* sr) const;
virtual void getGibbs_RT(doublereal* grt) const;
virtual void getCp_R(doublereal* cpr) const;
//! Returns the vector of nondimensional Internal Energies of the standard
//! state species at the current *T* and *P* of the solution
/*!
* For an incompressible, stoichiometric substance, the molar internal
* energy is independent of pressure. Since the thermodynamic properties are
* specified by giving the standard-state enthalpy, the term \f$ P_{ref}
* \hat v\f$ is subtracted from the specified reference molar enthalpy to
* compute the standard state molar internal energy.
*
* @param urt output vector of nondimensional standard state
* internal energies of the species. Length: m_kk.
*/
virtual void getIntEnergy_RT(doublereal* urt) const;
//! Get the molar volumes of each species in their standard states at the
//! current *T* and *P* of the solution.
/*
* units = m^3 / kmol
*
* We set this to zero
*
* @param vbar On output this contains the standard volume of the species
* and phase (m^3/kmol). Vector of length 1
*/
virtual void getStandardVolumes(doublereal* vbar) const;
//@}
/// @name Thermodynamic Values for the Species Reference States
//@{
virtual void getIntEnergy_RT_ref(doublereal* urt) const;
virtual void getEnthalpy_RT_ref(doublereal* hrt) const;
virtual void getGibbs_RT_ref(doublereal* grt) const;
virtual void getGibbs_ref(doublereal* g) const;
virtual void getEntropy_R_ref(doublereal* er) const;
virtual void getCp_R_ref(doublereal* cprt) const;
//@}
virtual void initThermoXML(XML_Node& phaseNode, const std::string& id);
virtual void initThermo();
//! Set the equation of state parameters
/*!
* @internal
* @param n number of parameters = 1
* @param c array of \a n coefficients
* c[0] = density of phase [ kg/m3 ]
*/
virtual void setParameters(int n, doublereal* const c);
//! Get the equation of state parameters in a vector
/*!
* @internal
*
* @param n number of parameters
* @param c array of \a n coefficients
*
* For this phase:
* - n = 1
* - c[0] = density of phase [ kg/m3 ]
*/
virtual void getParameters(int& n, doublereal* const c) const;
//! Set equation of state parameter values from XML entries.
/*!
* This method is called by function importPhase() when processing a phase
* definition in an input file. It should be overloaded in subclasses to set
* any parameters that are specific to that particular phase model. Note,
* this method is called before the phase is initialized with elements
* and/or species.
*
* For this phase, the chemical potential is set.
*
* @param eosdata An XML_Node object corresponding to
* the "thermo" entry for this phase in the input file.
*
* eosdata points to the thermo block, and looks like this:
*
* @code
* <phase id="stoichsolid" >
* <thermo model="FixedChemPot">
* <chemicalPotential units="J/kmol"> -2.7E7 </chemicalPotential>
* </thermo>
* </phase>
* @endcode
*/
virtual void setParametersFromXML(const XML_Node& eosdata);
//! Function to set the chemical potential directly
/*!
* @param chemPot Value of the chemical potential (units J/kmol)
*/
void setChemicalPotential(doublereal chemPot);
protected:
//! Value of the chemical potential of the bath species
/*!
* units are J/kmol
*/
doublereal chemPot_;
};
}
#endif