Cantera  2.0
Public Types | Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
MultiPhaseEquil Class Reference

Multiphase chemical equilibrium solver. More...

#include <MultiPhaseEquil.h>

Collaboration diagram for MultiPhaseEquil:

Public Types

typedef size_t index_t

Public Member Functions

 MultiPhaseEquil (MultiPhase *mix, bool start=true, int loglevel=0)
size_t constituent (index_t m)
void getStoichVector (index_t rxn, vector_fp &nu)
int iterations ()
doublereal equilibrate (int XY, doublereal err=1.0e-9, int maxsteps=1000, int loglevel=-99)
doublereal error ()
std::string reactionString (index_t j)
 Return a string specifying the jth reaction.
void printInfo (int loglevel)
void setInitialMixMoles (int loglevel=0)
size_t componentIndex (index_t n)
void reportCSV (const std::string &reportFile)
double phaseMoles (index_t iph) const

Protected Member Functions

void getComponents (const std::vector< size_t > &order)
 This method finds a set of component species and a complete set of formation reactions for the non-components in terms of the components.
int setInitialMoles (int loglevel=0)
 Estimate the initial mole numbers.
void computeN ()
doublereal stepComposition (int loglevel=0)
 Take one step in composition, given the gradient of G at the starting point, and a vector of reaction steps dxi.
void unsort (vector_fp &x)
 Re-arrange a vector of species properties in sorted form (components first) into unsorted, sequential form.
void step (doublereal omega, vector_fp &deltaN, int loglevel=0)
doublereal computeReactionSteps (vector_fp &dxi)
 Compute the change in extent of reaction for each reaction.
void updateMixMoles ()
void finish ()
 Clean up the composition.
double moles (size_t ns) const
double & moles (size_t ns)
int solutionSpecies (size_t n) const
bool isStoichPhase (size_t n) const
doublereal mu (size_t n) const
std::string speciesName (size_t n) const
index_t nFree () const
 Number of degrees of freedom.

Protected Attributes

index_t m_nel_mix
index_t m_nsp_mix
index_t m_np
index_t m_nel
index_t m_nsp
index_t m_eloc
int m_iter
doublereal m_press
doublereal m_temp
std::vector< size_t > m_order
DenseMatrix m_N
DenseMatrix m_A
vector_fp m_work
vector_fp m_work2
vector_fp m_work3
vector_fp m_moles
vector_fp m_lastmoles
vector_fp m_dxi
vector_fp m_deltaG_RT
vector_fp m_mu
std::vector< bool > m_majorsp
std::vector< size_t > m_sortindex
vector_int m_lastsort
vector_int m_dsoln
vector_int m_incl_element
vector_int m_incl_species
std::vector< size_t > m_species
std::vector< size_t > m_element
std::vector< bool > m_solnrxn
bool m_force

Detailed Description

Multiphase chemical equilibrium solver.

Class MultiPhaseEquil is designed to be used to set a mixture containing one or more phases to a state of chemical equilibrium. It implements the VCS algorithm, described in Smith and Missen, "Chemical Reaction Equilibrium."

This class only handles chemical equilibrium at a specified temperature and pressure. To compute equilibrium holding other properties fixed, it is necessary to iterate on T and P in an "outer" loop, until the specified properties have the desired values. This is done, for example, in method equilibrate of class MultiPhase.

This class is primarily meant to be used internally by the equilibrate method of class MultiPhase, although there is no reason it cannot be used directly in application programs if desired.

Definition at line 32 of file MultiPhaseEquil.h.

Constructor & Destructor Documentation

MultiPhaseEquil ( MultiPhase mix,
bool  start = true,
int  loglevel = 0 


Construct a multiphase equilibrium manager for a multiphase mixture.

mixPointer to a multiphase mixture object.
startIf true, the initial composition will be determined by a linear Gibbs minimization, otherwise the initial mixture composition will be used.

Definition at line 54 of file MultiPhaseEquil.cpp.

References DATA_PTR, MultiPhase::elementMoles(), MultiPhase::elementName(), ckr::max(), Cantera::multiply(), MultiPhase::nAtoms(), MultiPhase::nElements(), MultiPhaseEquil::nFree(), MultiPhase::nPhases(), MultiPhase::nSpecies(), MultiPhase::pressure(), DenseMatrix::resize(), MultiPhaseEquil::setInitialMoles(), MultiPhase::solutionSpecies(), MultiPhase::speciesMoles(), MultiPhase::speciesName(), MultiPhase::speciesPhaseIndex(), MultiPhase::temperature(), MultiPhase::tempOK(), and MultiPhaseEquil::unsort().

Member Function Documentation

string reactionString ( index_t  j)

Return a string specifying the jth reaction.

Definition at line 607 of file MultiPhaseEquil.cpp.

References Cantera::coeffString(), and MultiPhase::speciesName().

void getComponents ( const std::vector< size_t > &  order)

This method finds a set of component species and a complete set of formation reactions for the non-components in terms of the components.

Note that in most cases, many different component sets are possible, and therefore neither the components returned by this method nor the formation reactions are unique. The algorithm used here is described in Smith and Missen, Chemical Reaction Equilibrium Analysis.

The component species are taken to be the first M species in array 'species' that have linearly-independent compositions.

orderOn entry, vector order should contain species index numbers in the order of decreasing desirability as a component. For example, if it is desired to choose the components from among the major species, this array might list species index numbers in decreasing order of mole fraction. If array 'species' does not have length = nSpecies(), then the species will be considered as candidates to be components in declaration order, beginning with the first phase added.

Definition at line 399 of file MultiPhaseEquil.cpp.

References ckr::min(), MultiPhase::nAtoms(), MultiPhaseEquil::nFree(), Cantera::npos, and MultiPhase::solutionSpecies().

int setInitialMoles ( int  loglevel = 0)

Estimate the initial mole numbers.

This is done by running each reaction as far forward or backward as possible, subject to the constraint that all mole numbers remain non-negative. Reactions for which \( \Delta \mu^0 \) are positive are run in reverse, and ones for which it is negative are run in the forward direction. The end result is equivalent to solving the linear programming problem of minimizing the linear Gibbs function subject to the element and non-negativity constraints.

Definition at line 293 of file MultiPhaseEquil.cpp.

References Cantera::addLogEntry(), Cantera::beginLogGroup(), DATA_PTR, Cantera::endLogGroup(), MultiPhase::getValidChemPotentials(), and MultiPhaseEquil::nFree().

Referenced by MultiPhaseEquil::MultiPhaseEquil().

doublereal stepComposition ( int  loglevel = 0)
void unsort ( vector_fp x)

Re-arrange a vector of species properties in sorted form (components first) into unsorted, sequential form.

Definition at line 555 of file MultiPhaseEquil.cpp.

Referenced by MultiPhaseEquil::MultiPhaseEquil(), and MultiPhaseEquil::stepComposition().

doublereal computeReactionSteps ( vector_fp dxi)
void finish ( )

Clean up the composition.

The solution algorithm can leave some species in stoichiometric condensed phases with very small negative mole numbers. This method simply sets these to zero.

Definition at line 273 of file MultiPhaseEquil.cpp.

References DATA_PTR, and MultiPhase::setMoles().

index_t nFree ( ) const

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