Wall Combustion Scalar Option

Boundary condition available for the Flamelet Generated Manifold (FGM) model, the Steady Laminar Flamelet (SLF) model, the Chemical Equilibrium (CE) model, the Polymerization model, and some emissions models. Selects the scalars for the wall combustion calculation.

Wall Combustion Scalar Option

Wall Combustion Scalar	Corresponding Value Nodes
Zero Flux Corresponds to an impermeable wall.	None
Specified Value Values that are specified for the corresponding physics values nodes are prescribed at the wall. For the Polymerization model, see Polymerization Model Reference: Boundary Settings	Mixture Fraction Profile The mixture fraction is a measure of the local fuel/oxidizer ratio in a combustion system consisting of separate fuel and oxidizer streams. The Mixture Fraction Profile represents the reacting proportion of a fluid stream—the atomic mass fraction that originated from the fuel stream. 1.0 is equal to 100%. To initialize with pure oxidizer, maintain the default of 0.0. For inflows where the mixture is unburnt, the Mixture Fraction Profile is the mass fraction of the fuel. Mixture Fraction Variance Profile The mixture fraction variance is a measure of turbulent fluctuations in the local mixture fraction values. Progress Variable Not available when using the non-premixed SLF or CE models. The progress variable is a dimensionless parameter, Eqn. (3535), that shows the progress of the combustion. The Constant value is 0 for the unburnt state and 1 for the fully burnt state. Flame Area Density Only available when using the CFM model. The flame area per unit volume, $Σ$ in Eqn. (3555). Additional physics value nodes appear when the following soot or NOx models are selected: Soot Moments model: Soot Moment Profile Soot Two-Equation model: Soot Scaled Mass Density Profile and Soot Scaled Number Density Profile NOx Emission model: Nitrogen Oxide NOx Fuel model: Ammonia, Hydrogen Cyanide
Specified Flux Specifies the mass flux through the wall. It is assumed that the mixture fraction variance and the progress variable (for the FGM, TFC, and CFM models) is 0.0. Therefore, the specified wall flux is always treated as unburnt mixture. Activates the physics condition node, Wall Flux Temperature Specification	Mass Flux The mass flow rate per unit area at the boundary. Mixture Fraction Profile The default of 0.0 implies pure oxidizer, 1.0 implies pure fuel. Static Temperature The Static Temperature of the associated mass flux.

Wall Combustion Scalar

Corresponding Value Nodes

Zero Flux

Corresponds to an impermeable wall.

None

Specified Value

Values that are specified for the corresponding physics values nodes are prescribed at the wall.

For the Polymerization model, see Polymerization Model Reference: Boundary Settings

Mixture Fraction Profile: The mixture fraction is a measure of the local fuel/oxidizer ratio in a combustion system consisting of separate fuel and oxidizer streams. The Mixture Fraction Profile represents the reacting proportion of a fluid stream—the atomic mass fraction that originated from the fuel stream. 1.0 is equal to 100%. To initialize with pure oxidizer, maintain the default of 0.0. For inflows where the mixture is unburnt, the Mixture Fraction Profile is the mass fraction of the fuel.
Mixture Fraction Variance Profile: The mixture fraction variance is a measure of turbulent fluctuations in the local mixture fraction values.
Progress Variable: Not available when using the non-premixed SLF or CE models.; The progress variable is a dimensionless parameter, Eqn. (3535), that shows the progress of the combustion. The Constant value is 0 for the unburnt state and 1 for the fully burnt state.
Flame Area Density: Only available when using the CFM model.; The flame area per unit volume, $Σ$ in Eqn. (3555).

Additional physics value nodes appear when the following soot or NOx models are selected:

Soot Moments model: Soot Moment Profile
Soot Two-Equation model: Soot Scaled Mass Density Profile and Soot Scaled Number Density Profile
NOx Emission model: Nitrogen Oxide
NOx Fuel model: Ammonia, Hydrogen Cyanide

Specified Flux

Specifies the mass flux through the wall. It is assumed that the mixture fraction variance and the progress variable (for the FGM, TFC, and CFM models) is 0.0. Therefore, the specified wall flux is always treated as unburnt mixture.

Activates the physics condition node, Wall Flux Temperature Specification

Mass Flux: The mass flow rate per unit area at the boundary.
Mixture Fraction Profile: The default of 0.0 implies pure oxidizer, 1.0 implies pure fuel.
Static Temperature: The Static Temperature of the associated mass flux.

Wall Flux Temperature Specification

Based on the following specification, enthalpy due to the wall flux is added to the system.

Wall Flux Temperature Specification	Corresponding Value Node
Specified Value	Static Temperature The Static Temperature of the associated mass flux.
Wall Value The temperature of the mass flux entering the domain is taken as the wall temperature.	None