vcs_defs.h

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/**
 * @file vcs_defs.h
 *    Defines and definitions within the vcs package
 */
 
// 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 VCS_DEFS_H
#define VCS_DEFS_H
 
namespace Cantera
{
/*!
 *      ERROR CODES
 */
//! @{
#define VCS_SUCCESS 0
//! @}
 
//! @name  Sizes of Phases and Cutoff Mole Numbers
//!
//! All size parameters are listed here
//! @{
 
//! Cutoff relative mole fraction value, below which species are deleted from
//! the equilibrium problem.
#define VCS_RELDELETE_SPECIES_CUTOFF 1.0e-64
 
//! Cutoff relative mole number value, below which species are deleted from the
//! equilibrium problem.
#define VCS_DELETE_MINORSPECIES_CUTOFF 1.0e-140
 
//! Relative value of multiphase species mole number for a multiphase species
//! which is small.
#define VCS_SMALL_MULTIPHASE_SPECIES 1.0e-25
 
//! Cutoff relative moles below which a phase is deleted
//! from the equilibrium problem.
#define VCS_DELETE_PHASE_CUTOFF 1.0e-13
 
//! Cutoff moles below which a phase or species which comprises the bulk of an
//! element's total concentration is deleted.
#define VCS_DELETE_ELEMENTABS_CUTOFF 1.0e-280
 
//! Maximum steps in the inner loop
#define VCS_MAXSTEPS 50000
 
//! @}
 
//! @name  Species Categories used during the iteration
/*!
 * These defines are valid values for spStatus()
 */
//! @{
 
//! Species is a component which can be nonzero
#define VCS_SPECIES_COMPONENT 2
 
//! Species is a major species
/*!
 * A major species is either a species in a multicomponent phase with
 * significant concentration or it's a Stoich Phase
 */
#define VCS_SPECIES_MAJOR 1
 
//! Species is a major species
/*!
 * A major species is either a species in a multicomponent phase with
 * significant concentration or it's a Stoich Phase
 */
#define VCS_SPECIES_MINOR 0
 
//! Species lies in a multicomponent phase with concentration zero
/*!
 * The species lies in a multicomponent phase which currently doesn't exist.
 * It concentration is currently zero.
 */
#define VCS_SPECIES_ZEROEDMS -2
 
//! Species is a SS phase, that is currently zeroed out.
/*!
 * The species lies in a single-species phase which is currently zeroed out.
 */
#define VCS_SPECIES_ZEROEDSS -3
 
//! Species has such a small mole fraction it is deleted even though its
//! phase may possibly exist.
/*!
 * The species is believed to have such a small mole fraction that it best to
 * throw the calculation of it out. It will be added back in at the end of the
 * calculation.
 */
#define VCS_SPECIES_DELETED -4
 
//! Species refers to an electron in the metal.
/*!
 * The unknown is equal to the electric potential of the phase in which it
 * exists.
 */
#define VCS_SPECIES_INTERFACIALVOLTAGE -5
 
//! Species lies in a multicomponent phase that is zeroed atm
/*!
 * The species lies in a multicomponent phase that is currently deleted and will
 * stay deleted due to a choice from a higher level. These species will formally
 * always have zero mole numbers in the solution vector.
 */
#define VCS_SPECIES_ZEROEDPHASE -6
 
//! Species lies in a multicomponent phase that is active, but species
//! concentration is zero
/*!
 * The species lies in a multicomponent phase which currently does exist. It
 * concentration is currently identically zero, though the phase exists. Note,
 * this is a temporary condition that exists at the start of an equilibrium
 * problem. The species is soon "birthed" or "deleted".
 */
#define VCS_SPECIES_ACTIVEBUTZERO -7
 
//! Species lies in a multicomponent phase that is active,
//! but species concentration is zero due to stoich constraint
/*!
 * The species lies in a multicomponent phase which currently does exist.  Its
 * concentration is currently identically zero, though the phase exists. This is
 * a permanent condition due to stoich constraints.
 *
 * An example of this would be a species that contains Ni. But, the amount of Ni
 * elements in the current problem statement is exactly zero.
 */
#define VCS_SPECIES_STOICHZERO -8
 
//! @}
 
//! @name  Phase Categories used during the iteration
/*!
 * These defines are valid values for the phase existence flag
 */
//! @{
//! Always exists because it contains inerts which can't exist in any other phase
#define VCS_PHASE_EXIST_ALWAYS 3
 
//! Phase is a normal phase that currently exists
#define VCS_PHASE_EXIST_YES 2
 
//! Phase doesn't currently exist in the mixture
#define VCS_PHASE_EXIST_NO 0
 
//! Phase currently is zeroed due to a programmatic issue
/*!
 * We zero phases because we want to follow phase stability boundaries.
 */
#define VCS_PHASE_EXIST_ZEROEDPHASE -6
 
//! @}
//! @name Types of Element Constraint Equations
//!
//! There may be several different types of element constraints handled by the
//! equilibrium program.  These defines are used to assign each constraint to one
//! category.
//! @{
 
//! Normal element constraint consisting of positive coefficients for the
//! formula matrix.
/*!
 * All species have positive coefficients within the formula matrix. With this
 * constraint, we may employ various strategies to handle small values of the
 * element number successfully.
 */
#define VCS_ELEM_TYPE_ABSPOS 0
 
//! This refers to conservation of electrons
/*!
 * Electrons may have positive or negative values in the Formula matrix.
 */
#define VCS_ELEM_TYPE_ELECTRONCHARGE 1
 
//! This refers to a charge neutrality of a single phase
/*!
 * Charge neutrality may have positive or negative values in the Formula matrix.
 */
#define VCS_ELEM_TYPE_CHARGENEUTRALITY 2
 
//! @}
//! @name  Types of Species Unknowns in the problem
//! @{
 
//! Unknown refers to mole number of a single species
#define VCS_SPECIES_TYPE_MOLNUM 0
 
//! Unknown refers to the voltage level of a phase
/*!
 * Typically, these species are electrons in metals. There is an infinite supply
 * of them. However, their electrical potential is sometimes allowed to vary,
 * for example if the open circuit voltage is sought after.
 */
#define VCS_SPECIES_TYPE_INTERFACIALVOLTAGE -5
 
//! @}
//! @name  Types of State Calculations within VCS
//!
//! These values determine where the results are stored within the VCS_SOLVE object.
//! @{
 
//! State Calculation based on the old or base mole numbers
#define VCS_STATECALC_OLD 0
 
//! State Calculation based on the new or tentative mole numbers
#define VCS_STATECALC_NEW 1
 
//! State Calculation based on tentative mole numbers for a phase which is
//! currently zeroed, but is being evaluated for whether it should pop back into
//! existence
#define VCS_STATECALC_PHASESTABILITY 2
 
//! State Calculation based on a temporary set of mole numbers
#define VCS_STATECALC_TMP 3
//! @}
 
}
 
// namespace alias for backward compatibility
namespace VCSnonideal = Cantera;
 
#endif