Classes
class	MultiPhase
	A class for multiphase mixtures. More...

class	vcs_MultiPhaseEquil
	Cantera's Interface to the Multiphase chemical equilibrium solver. More...

Functions
int	equilibrate (thermo_t &s, const char *XY, int solver=-1, doublereal rtol=1.0e-9, int maxsteps=VCS_MAXSTEPS, int maxiter=100, int loglevel=-99)
	Equilibrate a ThermoPhase object. More...

doublereal	equilibrate (MultiPhase &s, const char *XY, doublereal rtol=1.0e-9, int maxsteps=5000, int maxiter=100, int loglevel=-99)
	Equilibrate a MultiPhase object. More...

void	equilibrate (const std::string &XY, const std::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 MultiPhase object. More...

size_t	BasisOptimize (int usedZeroedSpecies, bool doFormRxn, MultiPhase mphase, std::vector< size_t > &orderVectorSpecies, std::vector< size_t > &orderVectorElements, vector_fp &formRxnMatrix)
	Choose the optimum basis of species for the equilibrium calculations. More...

size_t	ElemRearrange (size_t nComponents, const vector_fp &elementAbundances, MultiPhase *mphase, std::vector< size_t > &orderVectorSpecies, std::vector< size_t > &orderVectorElements)
	Handles the potential rearrangement of the constraint equations represented by the Formula Matrix. More...

int	vcs_equilibrate (thermo_t &s, const char *XY, int estimateEquil=0, int printLvl=0, int solver=-1, doublereal rtol=1.0e-9, int maxsteps=VCS_MAXSTEPS, int maxiter=100, int loglevel=-99)
	Set a single-phase chemical solution to chemical equilibrium. More...

int	vcs_equilibrate (MultiPhase &s, const char *XY, int estimateEquil=0, int printLvl=0, int solver=2, doublereal rtol=1.0e-9, int maxsteps=VCS_MAXSTEPS, int maxiter=100, int loglevel=-99)
	Set a multi-phase chemical solution to chemical equilibrium. More...

int	vcs_equilibrate_1 (MultiPhase &s, int ixy, int estimateEquil=0, int printLvl=0, int solver=2, doublereal rtol=1.0e-9, int maxsteps=VCS_MAXSTEPS, int maxiter=100, int loglevel=-99)
	Set a multi-phase chemical solution to chemical equilibrium. More...

Chemical Equilibrium
Chemical equilibrium.
void	equilibrate (const std::string &XY, const std::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. More...

virtual void	setToEquilState (const doublereal *lambda_RT)
	This method is used by the ChemEquil equilibrium solver. More...

void	setElementPotentials (const vector_fp &lambda)
	Stores the element potentials in the ThermoPhase object. More...

bool	getElementPotentials (doublereal *lambda) const
	Returns the element potentials stored in the ThermoPhase object. More...

Detailed Description

Cantera has several different equilibrium routines.

Function Documentation

int equilibrate	(	thermo_t &	s,
		const char *	XY,
		int	solver = `-1`,
		doublereal	rtol = `1.0e-9`,
		int	maxsteps = `VCS_MAXSTEPS`,
		int	maxiter = `100`,
		int	loglevel = `-99`
	)

Equilibrate a ThermoPhase object.

Set a single-phase chemical solution to chemical equilibrium. This is a convenience function that uses one or the other of the two chemical equilibrium solvers. The XY parameter indicates what two thermodynamic quantities, other than element composition, are to be held constant during the equilibration process.

Parameters

s	ThermoPhase object that will be equilibrated.
XY	String representation of what two properties are being held constant
solver	ID of the solver to be used to equilibrate the phase. If solver = 0, the ChemEquil solver will be used, and if solver = 1, the MultiPhaseEquil solver will be used (slower than ChemEquil, but more stable). If solver < 0 (default, then ChemEquil will be tried first, and if it fails MultiPhaseEquil will be tried.
rtol	Relative tolerance
maxsteps	Maximum number of steps to take to find the solution
maxiter	For the MultiPhaseEquil solver only, this is the maximum number of outer temperature or pressure iterations to take when T and/or P is not held fixed.
loglevel	loglevel Controls amount of diagnostic output. loglevel = 0 suppresses diagnostics, and increasingly-verbose messages are written as loglevel increases.

Returns: The number of iterations it took to equilibrate the system.

Deprecated:: Use ThermoPhase::equilibrate instead. To be removed after Cantera 2.2.

Definition at line 34 of file equilibrate.cpp.

References MultiPhase::addPhase(), Cantera::equilibrate(), ChemEquil::equilibrate(), MultiPhase::init(), EquilOpt::maxIterations, ChemEquil::options, EquilOpt::relTolerance, CanteraError::save(), ThermoPhase::setElementPotentials(), Cantera::vcs_equilibrate(), and Cantera::warn_deprecated().

doublereal equilibrate	(	MultiPhase &	s,
		const char *	XY,
		doublereal	rtol = `1.0e-9`,
		int	maxsteps = `5000`,
		int	maxiter = `100`,
		int	loglevel = `-99`
	)

Equilibrate a MultiPhase object.

Equilibrate a MultiPhase object. The XY parameter indicates what two thermodynamic quantities, other than element composition, are to be held constant during the equilibration process.

This is the top-level driver for multiphase equilibrium. It doesn't do much more than call the equilibrate method of class MultiPhase, except that it adds some messages to the logfile, if loglevel is set > 0.

Parameters

s	MultiPhase object that will be equilibrated.
XY	String representation of what is being held constant
rtol	Relative tolerance
maxsteps	Maximum number of steps
maxiter	Maximum iterations
loglevel	loglevel

Returns: The number of iterations it took to equilibrate the system.

Deprecated:: Use MultiPhase::equilibrate instead. To be removed after Cantera 2.2.

Definition at line 11 of file equilibrate.cpp.

References Cantera::_equilflag(), MultiPhase::equilibrate(), MultiPhase::init(), CanteraError::save(), and Cantera::warn_deprecated().

Referenced by Cantera::equilibrate(), and Cantera::vcs_equilibrate().

void equilibrate	(	const std::string &	XY,
		const std::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 MultiPhase object.

Set this mixture to chemical equilibrium by calling one of Cantera's equilibrium solvers. The XY parameter indicates what two thermodynamic quantities are to be held constant during the equilibration process.

Parameters

XY	String representation of what two properties are being held constant
solver	Name of the solver to be used to equilibrate the phase. If solver = 'vcs', the vcs_MultiPhaseEquil solver will be used. If solver = 'gibbs', the MultiPhaseEquil solver will be used. If solver = 'auto', the 'vcs' solver will be tried first, followed by the 'gibbs' solver if the first one fails.
rtol	Relative tolerance
max_steps	Maximum number of steps to take to find the solution
max_iter	The maximum number of outer temperature or pressure iterations to take when T and/or P is not held fixed.
estimate_equil	integer indicating whether the solver should estimate its own initial condition. If 0, the initial mole fraction vector in the ThermoPhase object is used as the initial condition. If 1, the initial mole fraction vector is used if the element abundances are satisfied. If -1, the initial mole fraction vector is thrown out, and an estimate is formulated.
log_level	loglevel Controls amount of diagnostic output. log_level=0 suppresses diagnostics, and increasingly-verbose messages are written as loglevel increases.

Definition at line 757 of file MultiPhase.cpp.

References Cantera::_equilflag(), vcs_MultiPhaseEquil::equilibrate(), MultiPhase::equilibrate_MultiPhaseEquil(), Cantera::int2str(), MultiPhase::m_moleFractions, MultiPhase::m_moles, MultiPhase::m_press, MultiPhase::m_temp, MultiPhase::updatePhases(), and Cantera::writelog().

size_t BasisOptimize	(	int *	usedZeroedSpecies,
		bool	doFormRxn,
		MultiPhase *	mphase,
		std::vector< size_t > &	orderVectorSpecies,
		std::vector< size_t > &	orderVectorElements,
		vector_fp &	formRxnMatrix
	)

Choose the optimum basis of species for the equilibrium calculations.

This is done by choosing the species with the largest mole fraction not currently a linear combination of the previous components. Then, calculate the stoichiometric coefficient matrix for that basis.

Calculates the identity of the component species in the mechanism. Rearranges the solution data to put the component data at the front of the species list.

Then, calculates SC(J,I) the formation reactions for all noncomponent species in the mechanism.

Parameters

[in]	mphase	Pointer to the multiphase object. Contains the species mole fractions, which are used to pick the current optimal species component basis.
[in]	orderVectorElements	Order vector for the elements. The element rows in the formula matrix are rearranged according to this vector.
[in]	orderVectorSpecies	Order vector for the species. The species are rearranged according to this formula. The first nCompoments of this vector contain the calculated species components on exit.
[in]	doFormRxn	If true, the routine calculates the formation reaction matrix based on the calculated component species. If false, this step is skipped.
[out]	usedZeroedSpecies	= If true, then a species with a zero concentration was used as a component. The problem may be converged.
[out]	formRxnMatrix

Returns: The number of components.

Definition at line 28 of file BasisOptimize.cpp.

References Cantera::BasisOptimize_print_lvl, DATA_PTR, MultiPhase::elementName(), MultiPhase::getMoles(), MultiPhase::nAtoms(), MultiPhase::nElements(), Cantera::npos, MultiPhase::nSpecies(), print_stringTrunc(), MultiPhase::speciesName(), Cantera::writelog(), and Cantera::writelogf().

Referenced by ChemEquil::estimateElementPotentials().

size_t ElemRearrange	(	size_t	nComponents,
		const vector_fp &	elementAbundances,
		MultiPhase *	mphase,
		std::vector< size_t > &	orderVectorSpecies,
		std::vector< size_t > &	orderVectorElements
	)

Handles the potential rearrangement of the constraint equations represented by the Formula Matrix.

Rearrangement is only necessary when the number of components is less than the number of elements. For this case, some constraints can never be satisfied exactly, because the range space represented by the Formula Matrix of the components can't span the extra space. These constraints, which are out of the range space of the component Formula matrix entries, are migrated to the back of the Formula matrix.

A prototypical example is an extra element column in FormulaMatrix[], which is identically zero. For example, let's say that argon is has an element column in FormulaMatrix[], but no species in the mechanism actually contains argon. Then, nc < ne. Unless the entry for desired element abundance vector for Ar is zero, then this element abundance constraint can never be satisfied. The constraint vector is not in the range space of the formula matrix.

Also, without perturbation of FormulaMatrix[], BasisOptimize[] would produce a zero pivot because the matrix would be singular (unless the argon element column was already the last column of FormulaMatrix[].

This routine borrows heavily from BasisOptimize algorithm. It finds nc constraints which span the range space of the Component Formula matrix, and assigns them as the first nc components in the formula matrix. This guarantees that BasisOptimize has a nonsingular matrix to invert.

Parameters

[in]	nComponents	Number of components calculated previously.
[in]	elementAbundances	Current value of the element abundances
[in]	mphase	Input pointer to a MultiPhase object
[in]	orderVectorSpecies	input vector containing the ordering of the global species in mphase. This is used to extract the component basis of the mphase object.
[out]	orderVectorElements	Output vector containing the order of the elements that is necessary for calculation of the formula matrix.

Deprecated:

The return value for this function is deprecated. After Cantera 2.2, this function will return void.

Definition at line 424 of file BasisOptimize.cpp.

References Cantera::BasisOptimize_print_lvl, MultiPhase::elementName(), MultiPhase::nAtoms(), MultiPhase::nElements(), Cantera::npos, MultiPhase::nSpecies(), Cantera::writelog(), and Cantera::writelogf().

Referenced by ChemEquil::estimateElementPotentials().

int vcs_equilibrate	(	thermo_t &	s,
		const char *	XY,
		int	estimateEquil = `0`,
		int	printLvl = `0`,
		int	solver = `-1`,
		doublereal	rtol = `1.0e-9`,
		int	maxsteps = `VCS_MAXSTEPS`,
		int	maxiter = `100`,
		int	loglevel = `-99`
	)

Set a single-phase chemical solution to chemical equilibrium.

The function uses the element abundance vector that is currently consistent with the composition within the phase itself. Two other thermodynamic quantities, determined by the XY string, are held constant during the equilibration. This is a convenience function that uses one or the other of the two chemical equilibrium solvers.

Parameters

s	The object to set to an equilibrium state
XY	An integer specifying the two properties to be held constant.
estimateEquil	integer indicating whether the solver should estimate its own initial condition. If 0, the initial mole fraction vector in the ThermoPhase object is used as the initial condition. If 1, the initial mole fraction vector is used if the element abundances are satisfied. if -1, the initial mole fraction vector is thrown out, and an estimate is formulated.
printLvl	Determines the amount of printing that gets sent to stdout from the vcs package (Note, you may have to compile with debug flags to get some printing).
solver	The equilibrium solver to use. If solver = 0, the ChemEquil solver will be used, and if solver = 1, the vcs_MultiPhaseEquil solver will be used (slower than ChemEquil, but more stable). If solver < 0 (default, then ChemEquil will be tried first, and if it fails vcs_MultiPhaseEquil will be tried.
rtol	Relative tolerance of the solve. Defaults to 1.0E-9.
maxsteps	The maximum number of steps to take to find the solution.
maxiter	For the MultiPhaseEquil solver only, this is the maximum number of outer temperature or pressure iterations to take when T and/or P is not held fixed.
loglevel	Controls amount of diagnostic output. loglevel = 0 suppresses diagnostics, and increasingly-verbose messages are written as loglevel increases.

Deprecated:: Use ThermoPhase::equilibrate instead. To be removed after Cantera 2.2.

Definition at line 20 of file vcs_equilibrate.cpp.

References MultiPhase::addPhase(), Cantera::equilibrate(), ChemEquil::equilibrate(), MultiPhase::init(), EquilOpt::maxIterations, ChemEquil::options, EquilOpt::relTolerance, CanteraError::save(), ThermoPhase::setElementPotentials(), Cantera::vcs_equilibrate(), and Cantera::warn_deprecated().

Referenced by Cantera::equilibrate().

int vcs_equilibrate	(	MultiPhase &	s,
		const char *	XY,
		int	estimateEquil = `0`,
		int	printLvl = `0`,
		int	solver = `2`,
		doublereal	rtol = `1.0e-9`,
		int	maxsteps = `VCS_MAXSTEPS`,
		int	maxiter = `100`,
		int	loglevel = `-99`
	)

Set a multi-phase chemical solution to chemical equilibrium.

This function uses the vcs_MultiPhaseEquil interface to the vcs solver. The function uses the element abundance vector that is currently consistent with the composition within the phases themselves. Two other thermodynamic quantities, determined by the XY string, are held constant during the equilibration.

Parameters

s	The object to set to an equilibrium state
XY	A character string representing the unknowns to be held constant
estimateEquil	integer indicating whether the solver should estimate its own initial condition. If 0, the initial mole fraction vector in the ThermoPhase object is used as the initial condition. If 1, the initial mole fraction vector is used if the element abundances are satisfied. If -1, the initial mole fraction vector is thrown out, and an estimate is formulated.
printLvl	Determines the amount of printing that gets sent to stdout from the vcs package (Note, you may have to compile with debug flags to get some printing).
solver	Determines which solver is used. 1 MultiPhaseEquil solver 2 VCSnonideal Solver (default)
rtol	Relative tolerance of the solve. Defaults to 1.0E-9.
maxsteps	The maximum number of steps to take to find the solution.
maxiter	For the MultiPhaseEquil solver only, this is the maximum number of outer temperature or pressure iterations to take when T and/or P is not held fixed.
loglevel	Controls amount of diagnostic output. loglevel = 0 suppresses diagnostics, and increasingly-verbose messages are written as loglevel increases.

Deprecated:: Use MultiPhase::equilibrate instead. To be removed after Cantera 2.2.

Definition at line 97 of file vcs_equilibrate.cpp.

References Cantera::_equilflag(), and Cantera::vcs_equilibrate_1().

Referenced by Cantera::vcs_equilibrate().

int vcs_equilibrate_1	(	MultiPhase &	s,
		int	ixy,
		int	estimateEquil = `0`,
		int	printLvl = `0`,
		int	solver = `2`,
		doublereal	rtol = `1.0e-9`,
		int	maxsteps = `VCS_MAXSTEPS`,
		int	maxiter = `100`,
		int	loglevel = `-99`
	)

Set a multi-phase chemical solution to chemical equilibrium.

This function uses the vcs_MultiPhaseEquil interface to the vcs solver. The function uses the element abundance vector that is currently consistent with the composition within the phases themselves. Two other thermodynamic quantities, determined by the XY string, are held constant during the equilibration.

Parameters

s	The MultiPhase object to be set to an equilibrium state
ixy	An integer specifying the two properties to be held constant.
estimateEquil	integer indicating whether the solver should estimate its own initial condition. If 0, the initial mole fraction vector in the ThermoPhase object is used as the initial condition. If 1, the initial mole fraction vector is used if the element abundances are satisfied. if -1, the initial mole fraction vector is thrown out, and an estimate is formulated.
printLvl	Determines the amount of printing that gets sent to stdout from the vcs package (Note, you may have to compile with debug flags to get some printing).
solver	Determines which solver is used. 1 MultiPhaseEquil solver 2 VCSnonideal Solver (default)
rtol	Relative tolerance of the solve. Defaults to 1.0E-9.
maxsteps	The maximum number of steps to take to find the solution.
maxiter	For the MultiPhaseEquil solver only, this is the maximum number of outer temperature or pressure iterations to take when T and/or P is not held fixed.
loglevel	Controls amount of diagnostic output. loglevel = 0 suppresses diagnostics, and increasingly-verbose messages are written as loglevel increases.

Deprecated:: Use MultiPhase::equilibrate instead. To be removed after Cantera 2.2.

Definition at line 108 of file vcs_equilibrate.cpp.

References vcs_MultiPhaseEquil::equilibrate(), MultiPhase::equilibrate(), MultiPhase::init(), Cantera::int2str(), vcs_MultiPhaseEquil::reportCSV(), CanteraError::save(), and Cantera::warn_deprecated().

Referenced by Cantera::vcs_equilibrate().

void equilibrate	(	const std::string &	XY,
		const std::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.

Set this phase to chemical equilibrium by calling one of several equilibrium solvers. The XY parameter indicates what two thermodynamic quantities are to be held constant during the equilibration process.

Parameters

XY	String representation of what two properties are being held constant
solver	Name of the solver to be used to equilibrate the phase. If solver = 'element_potential', the ChemEquil element potential solver will be used. If solver = 'vcs', the VCS solver will be used. If solver = 'gibbs', the MultiPhaseEquil solver will be used. If solver = 'auto', the solvers will be tried in order if the initial solver(s) fail.
rtol	Relative tolerance
max_steps	Maximum number of steps to take to find the solution
max_iter	For the 'gibbs' and 'vcs' solvers, this is the maximum number of outer temperature or pressure iterations to take when T and/or P is not held fixed.
estimate_equil	integer indicating whether the solver should estimate its own initial condition. If 0, the initial mole fraction vector in the ThermoPhase object is used as the initial condition. If 1, the initial mole fraction vector is used if the element abundances are satisfied. If -1, the initial mole fraction vector is thrown out, and an estimate is formulated.
log_level	loglevel Controls amount of diagnostic output. log_level=0 suppresses diagnostics, and increasingly-verbose messages are written as loglevel increases.

Definition at line 748 of file ThermoPhase.cpp.

References MultiPhase::addPhase(), ChemEquil::equilibrate(), MultiPhase::equilibrate(), MultiPhase::init(), Cantera::int2str(), EquilOpt::maxIterations, ChemEquil::options, EquilOpt::relTolerance, Phase::restoreState(), Phase::saveState(), ThermoPhase::setElementPotentials(), and Cantera::writelog().

virtual void setToEquilState ( const doublereal * lambda_RT )

inlinevirtual

This method is used by the ChemEquil equilibrium solver.

It sets the state such that the chemical potentials satisfy

\[ \frac{\mu_k}{\hat R T} = \sum_m A_{k,m} \left(\frac{\lambda_m} {\hat R T}\right) \]

where \( \lambda_m \) is the element potential of element m. The temperature is unchanged. Any phase (ideal or not) that implements this method can be equilibrated by ChemEquil.

Parameters

lambda_RT Input vector of dimensionless element potentials The length is equal to nElements().

Reimplemented in HMWSoln, DebyeHuckel, IdealGasPhase, IdealSolidSolnPhase, MolalityVPSSTP, IdealMolalSoln, RedlichKwongMFTP, IdealSolnGasVPSS, and ConstDensityThermo.

Definition at line 1186 of file ThermoPhase.h.

Referenced by ChemEquil::setToEquilState().

void setElementPotentials ( const vector_fp & lambda )

Stores the element potentials in the ThermoPhase object.

Called by the ChemEquil equilibrium solver to transfer the element potentials to this object after every successful equilibration routine. The element potentials are stored in their dimensionless forms, calculated by dividing by RT.

Parameters

lambda Input vector containing the element potentials. Length = nElements. Units are Joules/kmol.

Definition at line 796 of file ThermoPhase.cpp.

References Cantera::GasConstant, ThermoPhase::m_hasElementPotentials, ThermoPhase::m_lambdaRRT, Phase::nElements(), Cantera::scale(), and Phase::temperature().

Referenced by Cantera::equilibrate(), ChemEquil::equilibrate(), ThermoPhase::equilibrate(), and Cantera::vcs_equilibrate().

bool getElementPotentials ( doublereal * lambda ) const

Returns the element potentials stored in the ThermoPhase object.

Returns the stored element potentials. The element potentials are retrieved from their stored dimensionless forms by multiplying by RT.

Parameters

lambda Output vector containing the element potentials. Length = nElements. Units are Joules/kmol.

Returns: bool indicating whether there are any valid stored element potentials. The calling routine should check this bool. In the case that there aren't any, lambda is not touched.

Definition at line 809 of file ThermoPhase.cpp.

References Cantera::GasConstant, ThermoPhase::m_hasElementPotentials, ThermoPhase::m_lambdaRRT, Cantera::scale(), and Phase::temperature().

Referenced by ChemEquil::equilibrate().

Classes

Functions

Chemical Equilibrium

Detailed Description

Function Documentation