This section is referenced in the following other sections

- Simulation Setup: Fixed

# 7.12.1. Fixed Boundary Condition On Surface

Scope

  Fuego Region

Summary

  Defines a fixed boundary condition on a named surface of the mesh.

    begin Fixed Boundary Condition On Surface Surfacename

        {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} {=} Value

       Emissivity Spectral File Name {=} Name

       External Field For VariableName [{of} Species] {=} ExtFieldName [ Of Size Value With Multiplier {=} Multiplier  ]

       Emissivity {=} value

       Function For {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} {=} FuncName [ In The {t | x | y | z} Direction  ]

       Function For Emissivity {=} functionName [ In The {t | x | y | z} Direction  ]

       Function For Mass_Fraction {=} FuncName In The {t | x | y | z} Direction

       Function For Mole_Fraction {=} FuncName In The {t | x | y | z} Direction

       Function For Radiation Boundary Temperature {=} functionName

       Function For Radiation Environment Temperature {=} functionName

       Function For Transmissivity {=} functionName [ In The {t | x | y | z} Direction  ]

       Function For Transparent Band Emissivity {=} functionName [ In The {t | x | y | z} Direction  ]

       Inline Function For {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} {=} FuncStr

       Integer Data For Subroutine SubName {=} Values...

       Mass_Fraction Species {=} Mass fraction

       Mole_Fraction Species {=} Mole fraction

       Postprocess FluxType Flux Of {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} [ As aliases...  ]

       Progress_Variable ProgressVariableName {=} Value

       Real Data For Subroutine SubName {=} Values...

       Radiation Boundary Temperature {=} value

       Radiation Boundary Temperature Field {=} FieldName

       Radiation Environment Temperature {=} value

       Radiation Environment Temperature Field {=} FieldName

       Subroutine For {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} {=} Subroutine

       Subroutine For Emissivity {=} subroutineName

       Subroutine For Mass_Fraction {=} Subroutine

       Subroutine For Mole_Fraction {=} Subroutine

       Subroutine For Radiation Boundary Temperature {=} subroutineName

       Subroutine For Radiation Environment Temperature {=} subroutineName

       Subroutine For Transmissivity {=} subroutineName

       Subroutine For Transparent Band Emissivity {=} subroutineName

       Transparent Band Emissivity {=} value

       Transmissivity {=} value

    end Fixed Boundary Condition On Surface Surfacename

## 7.12.1.1. Line Commands

###### Primitivevariable

Syntax

  Primitivevariable {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} {=} Value

Summary

  Value for the specified variable (in consistent units). Value can be a constant or a string function of position (x,y,z), time (t), and any global variable.

  The function string must be enclosed in quotes if it has spaces or commas. For example: x_velocity = “min(1, 0.1*t)”

Parameter | Value | Default
--- | --- | ---
PrimitiveVariable | {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} | –
{=} | {= | are | is} | –
Value | “string” | –

###### Emissivity Spectral File Name

Syntax

  Emissivity Spectral File Name {=} Name

Summary

  Specify the file name for defining spectral radiation properties on a surface.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Name | string | –

###### External Field For

Syntax

  External Field For VariableName [{of} Species] {=} ExtFieldName [ Of Size Value With Multiplier {=} Multiplier ]

Summary

  Name of the field that is to be transferred in. For species equation, specify variable as “mass fraction of” followed by the species name for transfers associated with separated individual species field names.

Parameter | Value | Default
--- | --- | ---
VariableName | string | –
Species | string | –
{=} | {= | are | is} | –
ExtFieldName | string | –

###### Emissivity

Syntax

  Emissivity {=} value

Summary

  Constant value for emissivity variable.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
value | “string” | –

###### Function For

Syntax

  Function For {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} {=} FuncName [ In The {t | x | y | z} Direction ]

Summary

  Name of function to use for the given variable, in the specified direction.

Parameter | Value | Default
--- | --- | ---
PrimitiveVariable | {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} | –
{=} | {= | are | is} | –
FuncName | string | –

###### Function For Emissivity

Syntax

  Function For Emissivity {=} functionName [ In The {t | x | y | z} Direction ]

Summary

  Name of the function to use for the emissivity in the given direction (default direction = time).

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
functionName | string | –

###### Function For Mass_Fraction

Syntax

  Function For Mass_Fraction {=} FuncName In The {t | x | y | z} Direction

Summary

  Name of the mass fraction function to use for all species in the given direction. Note that this must be a Multicolumn function

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
FuncName | string | –
Direction | {t | x | y | z} | –

###### Function For Mole_Fraction

Syntax

  Function For Mole_Fraction {=} FuncName In The {t | x | y | z} Direction

Summary

  Name of the mass fraction function to use for all species in the given direction. Note that this must be a Multicolumn function

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
FuncName | string | –
Direction | {t | x | y | z} | –

###### Function For Radiation Boundary Temperature

Syntax

  Function For Radiation Boundary Temperature {=} functionName

Summary

  Name of function to use for the radiation_boundary_temperature variable

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
functionName | string | –

###### Function For Radiation Environment Temperature

Syntax

  Function For Radiation Environment Temperature {=} functionName

Summary

  Name of function to use for the radiation_environment_temperature variable

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
functionName | string | –

###### Function For Transmissivity

Syntax

  Function For Transmissivity {=} functionName [ In The {t | x | y | z} Direction ]

Summary

  Name of function to use for the transmissivity variable

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
functionName | string | –

###### Function For Transparent Band Emissivity

Syntax

  Function For Transparent Band Emissivity {=} functionName [ In The {t | x | y | z} Direction ]

Summary

  Name of function to use for the transparent emissivity band for spectral emissivity on surfaces.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
functionName | string | –

###### Inline Function For

Syntax

  Inline Function For {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} {=} FuncStr

Summary

  warning{This command is deprecated. Regular BCs now support using string functions directly}

Parameter | Value | Default
--- | --- | ---
PrimitiveVariable | {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} | –
{=} | {= | are | is} | –
FuncStr | “string” | –

###### Integer Data For Subroutine

Syntax

  Integer Data For Subroutine SubName {=} Values…

Summary

  List of integer data values to be passed down in to the user subroutine. These values may be changed by the user subroutine.

Parameter | Value | Default
--- | --- | ---
SubName | string | –
{=} | {= | are | is} | –
Values | integer… | –

###### Mass_Fraction

Syntax

  Mass_Fraction Species {=} Mass fraction

Summary

  Value for the mass fraction of selected species. Can be a constant value or a string function of space (x,y,z), time (t), and any global variable.

Parameter | Value | Default
--- | --- | ---
Species | string | –
{=} | {= | are | is} | –
Mass fraction | “string” | –

###### Mole_Fraction

Syntax

  Mole_Fraction Species {=} Mole fraction

Summary

  Value for the mole fraction of selected species. Can be a constant value or a string function of space (x,y,z), time (t), and any global variable.

Parameter | Value | Default
--- | --- | ---
Species | string | –
{=} | {= | are | is} | –
Mole fraction | “string” | –

###### Postprocess

Syntax

  Postprocess FluxType Flux Of {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} [ As aliases… ]

Summary

  Enable nodal flux post-processing for a given equation. Flux types can be “total”, “advective”, or “diffusive”. Integrated fluxes will also be output to global variables for post-processing or use in other string functions.

  By default the variables will be named based on the equation and sideset they are applied to as bc_FluxType_EquationName_flux_SurfaceName. However, if you want to assign a more compact or descriptive name you can provide it with

      POSTPROCESS TOTAL FLUX OF Continuity AS mdot1

  When post-processing enthalpy, the average temperature is also output as a global variable. If you provide only one alias the enthalpy flux uses your alias and the average temperature is automatically named. If you provide two aliases the first is used for enthalpy and the second is used for temperature.

      POSTPROCESS TOTAL FLUX OF ENTHALPY AS hFlux
      POSTPROCESS TOTAL FLUX OF ENTHALPY AS hFlux Tavg

  When post-processing species, the post-processor is run for each species that is solved for. This means that there is no post-processor run on the last species (which is determined by a fractional balance). If you provide aliases for the species post-processor you should provide one for each post-processed species. For example, in a problem with O2, CO2, and N2 (in that order) you could use:

      POSTPROCESS TOTAL FLUX OF SPECIES AS mdotO2 mdotCO2

Parameter | Value | Default
--- | --- | ---
FluxType | string | –
equation | {conserved_enthalpy | continuity | edc_product | enthalpy | mixture_fraction | nuclei | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot | species | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_momentum | x_solid_momentum | y_momentum | y_solid_momentum | z_momentum | z_solid_momentum} | –

###### Progress_Variable

Syntax

  Progress_Variable ProgressVariableName {=} Value

Summary

  Constant value for the progress variable of selected scalars.

Parameter | Value | Default
--- | --- | ---
ProgressVariableName | string | –
{=} | {= | are | is} | –
Value | real | –

###### Real Data For Subroutine

Syntax

  Real Data For Subroutine SubName {=} Values…

Summary

  List of real data values to be passed down in to the user subroutine. These values may be changed by the user subroutine.

Parameter | Value | Default
--- | --- | ---
SubName | string | –
{=} | {= | are | is} | –
Values | real… | –

###### Radiation Boundary Temperature

Syntax

  Radiation Boundary Temperature {=} value

Summary

  Constant value for radiation_boundary_temperature variable.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
value | “string” | –

###### Radiation Boundary Temperature Field

Syntax

  Radiation Boundary Temperature Field {=} FieldName

Summary

  Name of the field to use for the radiation boundary temperature.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
FieldName | string | –

###### Radiation Environment Temperature

Syntax

  Radiation Environment Temperature {=} value

Summary

  Constant value for radiation_environment_temperature variable.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
value | “string” | –

###### Radiation Environment Temperature Field

Syntax

  Radiation Environment Temperature Field {=} FieldName

Summary

  Name of the field to use for the radiation environment temperature.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
FieldName | string | –

###### Subroutine For

Syntax

  Subroutine For {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} {=} Subroutine

Summary

  Name of the subroutine to use for this variable.

Parameter | Value | Default
--- | --- | ---
PrimitiveVariable | {contact_angle | edc_product | gas_volume_fraction | mixture_fraction | pressure | progress_variable | scalar_variance | second_mixture_fraction | solid_volume_fraction | soot_mass_fraction | soot_nuclei_mass_fraction | temperature | turbulent_dissipation | turbulent_frequency | turbulent_helmholtz_function | turbulent_kinetic_energy | turbulent_v2 | volume_of_fluid | x_solid_velocity | x_velocity | y_solid_velocity | y_velocity | z_solid_velocity | z_velocity} | –
{=} | {= | are | is} | –
Subroutine | string | –

###### Subroutine For Emissivity

Syntax

  Subroutine For Emissivity {=} subroutineName

Summary

  Name of the user subroutine to use for the emissivity variable.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
subroutineName | string | –

###### Subroutine For Mass_Fraction

Syntax

  Subroutine For Mass_Fraction {=} Subroutine

Summary

  Name of the subroutine to use for the mass fraction. ALL species mass fractions must be assigned by this subroutine.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Subroutine | string | –

###### Subroutine For Mole_Fraction

Syntax

  Subroutine For Mole_Fraction {=} Subroutine

Summary

  Name of the subroutine to use for the mole fractions. ALL species mole fractions must be assigned by this subroutine.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
Subroutine | string | –

###### Subroutine For Radiation Boundary Temperature

Syntax

  Subroutine For Radiation Boundary Temperature {=} subroutineName

Summary

  Name of the user subroutine to use for the radiation_boundary_temperature variable.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
subroutineName | string | –

###### Subroutine For Radiation Environment Temperature

Syntax

  Subroutine For Radiation Environment Temperature {=} subroutineName

Summary

  Name of the user subroutine to use for the radiation_environment_temperature variable.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
subroutineName | string | –

###### Subroutine For Transmissivity

Syntax

  Subroutine For Transmissivity {=} subroutineName

Summary

  Name of the user subroutine to use for the transmissivity variable.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
subroutineName | string | –

###### Subroutine For Transparent Band Emissivity

Syntax

  Subroutine For Transparent Band Emissivity {=} subroutineName

Summary

  Name of the user subroutine to use for the transparent emissivity band for spectral emissivity on surfaces.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
subroutineName | string | –

###### Transparent Band Emissivity

Syntax

  Transparent Band Emissivity {=} value

Summary

  Constant value to use for the emissivity in the transparent band for spectral surfaces.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
value | “string” | –

###### Transmissivity

Syntax

  Transmissivity {=} value

Summary

  Constant value for transmissivity variable.

Parameter | Value | Default
--- | --- | ---
{=} | {= | are | is} | –
value | “string” | –