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)
	Constructor.

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

MultiPhase *	m_mix

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`
	)

Constructor.

Construct a multiphase equilibrium manager for a multiphase mixture.

Parameters

mix	Pointer to a multiphase mixture object.
start	If 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 )

protected

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.

Parameters

order On 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 )

protected

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 )

protected

Take one step in composition, given the gradient of G at the starting point, and a vector of reaction steps dxi.

Definition at line 673 of file MultiPhaseEquil.cpp.

References Cantera::addLogEntry(), Cantera::beginLogGroup(), MultiPhaseEquil::computeReactionSteps(), DATA_PTR, Cantera::endLogGroup(), Cantera::fp2str(), MultiPhase::getValidChemPotentials(), Cantera::multiply(), MultiPhaseEquil::nFree(), MultiPhase::speciesName(), Cantera::Tiny, and MultiPhaseEquil::unsort().

void unsort ( vector_fp & x )

protected

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 )

protected

Compute the change in extent of reaction for each reaction.

Definition at line 782 of file MultiPhaseEquil.cpp.

References DATA_PTR, Cantera::GasConstant, MultiPhase::getValidChemPotentials(), MultiPhaseEquil::nFree(), Phase::nSpecies(), MultiPhase::phase(), MultiPhase::phaseMoles(), MultiPhase::speciesMoles(), and MultiPhase::speciesPhaseIndex().

Referenced by MultiPhaseEquil::stepComposition().

void finish ( )

protected

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

inlineprotected

Number of degrees of freedom.

Definition at line 127 of file MultiPhaseEquil.h.

Referenced by MultiPhaseEquil::computeReactionSteps(), MultiPhaseEquil::getComponents(), MultiPhaseEquil::MultiPhaseEquil(), MultiPhaseEquil::setInitialMoles(), and MultiPhaseEquil::stepComposition().

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

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation