Phase Thermodynamic Models#

On this page, we list the phase thermodynamic models implemented in Cantera, with links to the documentation for their YAML input parameters and the documentation for the C++ classes which implement these models. This API documentation may also provide references or a mathematical description of the model.

Cantera has a wide variety of models for bulk phases. Special attention has been paid to the performance of the ideal gas phase implementation, which is widely used in combustion applications. Non-ideal liquid phase thermodynamic models are provided for use in electrochemical and battery applications. These models include a Pitzer implementation for brine solutions and a Margules excess Gibbs free energy implementation for molten salts.

Models for Gaseous Mixtures#

Ideal Gas Mixture: A mixture which follows the ideal gas law. Defined in the YAML format by specifying ideal-gas in the thermo field of the phase definition. Implemented by class IdealGasPhase.

Redlich-Kwong Real Gas Mixture: A multi-species real gas following the Redlich-Kwong equation of state. Defined in the YAML format by specifying Redlich-Kwong in the thermo field of the phase definition. Implemented by class RedlichKwongMFTP.

Peng-Robinson Real Gas Mixture: A multi-species real gas following the Peng-Robinson equation of state. Defined in the YAML format by specifying Peng-Robinson in the thermo field of the phase definition. Implemented by class PengRobinson.

Plasma: A phase that extends the ideal gas model to handle plasma properties such as the electron energy distribution and electron temperature with different models. Defined in the YAML format by specifying plasma in the thermo field of the phase definition. Implemented by class PlasmaPhase.

Models for Surfaces and Interfaces#

Ideal Surface: An interface between two bulk phases where the species behave as an ideal solution and the composition is described by the coverage of each species on the surface. Defined in the YAML format by specifying ideal-surface in the thermo field of the phase definition. Implemented by class SurfPhase.

Surface Phase with Coverage-Dependent Thermo: A coverage-dependent surface phase. That is, a surface phase where the enthalpy, entropy, and heat capacity of each species may depend on its coverage and the coverage of other species in the phase. Defined in the YAML format by specifying coverage-dependent-surface in the thermo field of the phase definition. Implemented by class CoverageDependentSurfPhase.

Edge: A one-dimensional edge between two surfaces, which defines a triple phase boundary. Defined in the YAML format by specifying edge in the thermo field of the phase definition. Implemented by class EdgePhase.

Single-species Phase Models#

Stoichiometric Substance: A stoichiometric substance is one that is modeled as having a precise, fixed composition, given by the composition of the one species present. Defined in the YAML format by specifying fixed-stoichiometry in the thermo field of the phase definition. Implemented by class StoichSubstance.

Electron Cloud: A phase representing an electron cloud, such as conduction electrons in a metal. Defined in the YAML format by specifying electron-cloud in the thermo field of the phase definition. Implemented by class MetalPhase.

Pure Fluid Phases: A phase representing a pure fluid equation of state for one of several pure substances including liquid, vapor, two-phase, and supercritical regions. Defined in the YAML format by specifying pure-fluid in the thermo field of the phase definition. Implemented by class PureFluidPhase.

Liquid Water using the IAPWS95 Equation of State: An implementation of the IAPWS95 equation of state for water [Wagner and Pruß, 2002], for the liquid region only. Defined in the YAML format by specifying liquid-water-IAPWS95 in the thermo field of the phase definition. Implemented by class WaterSSTP.

Ideal Solid and Liquid Solutions#

Ideal Molal Solution: An ideal solution based on the mixing-rule assumption that all molality-based activity coefficients are equal to one. Defined in the YAML format by specifying ideal-molal-solution in the thermo field of the phase definition. Implemented by class IdealMolalSoln.

Ideal Condensed Phase: An ideal liquid or solid solution based on the mixing-rule assumption that all molar concentration-based activity coefficients are equal to one. Defined in the YAML format by specifying ideal-condensed in the thermo field of the phase definition. Implemented by class IdealSolidSolnPhase.

Ideal Condensed Phase with VPSS Species: An ideal solution model using variable pressure standard state methods. This allows the standard state molar volume of species to be specified as a function of temperature. Defined in the YAML format by specifying ideal-solution-VPSS in the thermo field of the phase definition. Implemented by class IdealSolnGasVPSS.

Lattice Phase: A simple thermodynamic model for a bulk phase, assuming an incompressible lattice of solid atoms. Defined in the YAML format by specifying lattice in the thermo field of the phase definition. Implemented by class LatticePhase.

Compound Lattice Phase: A phase that is comprised of a fixed additive combination of other lattice phases. Defined in the YAML format by specifying compound-lattice in the thermo field of the phase definition. Implemented by class LatticeSolidPhase.

Non-ideal Solid and Liquid Solutions#

Binary Solution with Tabulated Enthalpy and Entropy: A phase representing a non-ideal binary solution where the excess enthalpy and entropy are interpolated between tabulated values as a function of mole fraction. Defined in the YAML format by specifying binary-solution-tabulated in the thermo field of the phase definition. Implemented by class BinarySolutionTabulatedThermo.

Debye-Huckel Solution: A dilute liquid electrolyte which obeys the Debye-Hückel formulation for nonideality. Defined in the YAML format by specifying Debye-Huckel in the thermo field of the phase definition. Implemented by class DebyeHuckel.

Harvie–Møller–Weare electrolyte: A dilute or concentrated liquid electrolyte phase that obeys the Pitzer formulation for nonideality. Defined in the YAML format by specifying HMW-electrolyte in the thermo field of the phase definition. Implemented by class HMWSoln.

Margules Solution: A condensed phase employing the Margules approximation for the excess Gibbs free energy. Defined in the YAML format by specifying Margules in the thermo field of the phase definition. Implemented by class MargulesVPSSTP.

Redlich-Kister Solution: A phase employing the Redlich-Kister approximation for the excess Gibbs free energy. Defined in the YAML format by specifying Redlich-Kister in the thermo field of the phase definition. Implemented by class RedlichKisterVPSSTP.