Multiphase chemical equilibrium solver. More...

#include <MultiPhaseEquil.h>

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 [40].

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.

Public Member Functions
	MultiPhaseEquil (MultiPhase *mix, bool start=true, int loglevel=0)
	Construct a multiphase equilibrium manager for a multiphase mixture. More...

size_t	constituent (size_t m)

void	getStoichVector (size_t rxn, vector< double > &nu)

int	iterations ()

double	equilibrate (int XY, double err=1.0e-9, int maxsteps=1000, int loglevel=-99)

double	error ()

string	reactionString (size_t j)

void	setInitialMixMoles (int loglevel=0)

size_t	componentIndex (size_t n)

void	reportCSV (const string &reportFile)

double	phaseMoles (size_t iph) const

Protected Member Functions
void	getComponents (const 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. More...

int	setInitialMoles (int loglevel=0)
	Estimate the initial mole numbers. More...

void	computeN ()

double	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. More...

void	unsort (vector< double > &x)
	Re-arrange a vector of species properties in sorted form (components first) into unsorted, sequential form. More...

void	step (double omega, vector< double > &deltaN, int loglevel=0)

double	computeReactionSteps (vector< double > &dxi)
	Compute the change in extent of reaction for each reaction. More...

void	updateMixMoles ()

void	finish ()
	Clean up the composition. More...

double	moles (size_t ns) const

double &	moles (size_t ns)

int	solutionSpecies (size_t n) const

bool	isStoichPhase (size_t n) const

double	mu (size_t n) const

string	speciesName (size_t n) const

size_t	nFree () const
	Number of degrees of freedom. More...

Protected Attributes
size_t	m_nel_mix

size_t	m_nsp_mix

size_t	m_nel = 0

size_t	m_nsp = 0

size_t	m_eloc = 1000

int	m_iter

MultiPhase *	m_mix

double	m_press

double	m_temp

vector< size_t >	m_order

DenseMatrix	m_N

DenseMatrix	m_A

vector< double >	m_work

vector< double >	m_work2

vector< double >	m_work3

vector< double >	m_moles

vector< double >	m_lastmoles

vector< double >	m_dxi

vector< double >	m_deltaG_RT

vector< double >	m_mu

vector< bool >	m_majorsp

vector< size_t >	m_sortindex

vector< int >	m_lastsort

vector< int >	m_dsoln

vector< int >	m_incl_element

vector< int >	m_incl_species

vector< size_t >	m_species

vector< size_t >	m_element

vector< bool >	m_solnrxn

bool	m_force = true

Constructor & Destructor Documentation

◆ MultiPhaseEquil()

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

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.
loglevel	Desired level of debug printing. loglevel = 0 suppresses printing. Higher values request more verbose logging output.

Definition at line 18 of file MultiPhaseEquil.cpp.

Member Function Documentation

◆ getComponents()

void getComponents ( const 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.

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 [40].

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 249 of file MultiPhaseEquil.cpp.

◆ setInitialMoles()

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 192 of file MultiPhaseEquil.cpp.

◆ stepComposition()

double 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 425 of file MultiPhaseEquil.cpp.

◆ unsort()

void unsort ( vector< double > & x )

protected

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

Definition at line 392 of file MultiPhaseEquil.cpp.

◆ computeReactionSteps()

double computeReactionSteps ( vector< double > & dxi )

protected

Compute the change in extent of reaction for each reaction.

Definition at line 508 of file MultiPhaseEquil.cpp.

◆ finish()

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 183 of file MultiPhaseEquil.cpp.

◆ nFree()

size_t nFree ( ) const

inlineprotected

Number of degrees of freedom.

Definition at line 163 of file MultiPhaseEquil.h.

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

Detailed Description

Public Member Functions

Protected Member Functions

Protected Attributes

Constructor & Destructor Documentation

◆ MultiPhaseEquil()

Member Function Documentation

◆ getComponents()

◆ setInitialMoles()

◆ stepComposition()

◆ unsort()

◆ computeReactionSteps()

◆ finish()

◆ nFree()