The
Define/Models/Species/Transport & Reaction... menu item opens the
Species Model panel.
Species Model Panel
The
Species Model panel allows you to set parameters related to the calculation of species transport and combustion. See Sections
14.1.3,
14.2.3,
14.3.2,
16.3,
17.3, and
18.3 for details about the items below.
Controls
Model
indicates which model, if any, is used to calculate species transport/combustion.
Off
disables species calculations.
Species Transport
enables the calculation of multi-species transport (either non-reacting or reacting, depending on the selection for
Reactions). See Chapter
14 for details.
Non-Premixed Combustion
enables the calculation of turbulent reacting flow using the non-premixed combustion model. See Chapter
15 for details. This option is available only for turbulent flows using the pressure-based solver.
Premixed Combustion
enables the premixed turbulent combustion model. See Chapter
16 for details. This option is available only for turbulent flows using the pressure-based solver.
Partially Premixed Combustion
enables the partially premixed turbulent combustion model. See Chapter
17 for details. This option is available only for turbulent flows using the pressure-based solver.
Composition PDF Transport
enables the composition PDF transport model. See Chapter
18 for details. This option is available only for turbulent flows using the pressure-based solver.
Reactions
contains options related to the modeling of reacting flow. (This section of the panel appears only when
Species Transport or
Composition PDF Transport is the specified
Model.)
Volumetric
enables the calculation of reacting flow using the finite-rate formulation. See Section
14.1 for details.
Wall Surface
enables the calculation of wall surface reactions. See Section
14.2 for details. This item will appear only if
Volumetric is enabled.
Particle Surface
enables the calculation of particle surface reactions. See Section
14.3 for details. This item will appear only if
Volumetric is enabled.
Integration Parameters...
is a command button that opens the
Integration Parameters panel. This button appears for the species transport model, when
Volumetric is enabled under
Reactions and
Stiff Chemistry Solver is enabled under
Options or when
EDC is enabled under
Turbulence-Chemistry Interaction.
Wall Surface Reaction Options
contains additional options for wall surface reactions. This portion of the panel appears only if
Wall Surface is enabled under
Reactions.
Heat of Surface Reactions
(if enabled) includes the heat release due to surface reactions in the energy equation. You must remember to set appropriate formation enthalpies (standard state enthalpies) if you enable this option.
Mass Deposition Source
(if enabled) includes the effect of surface mass transfer in the continuity equation.
Options
contains additional options for the
Species Transport model and for the
Composition PDF Transport. (This section will not appear in the panel for the other models.)
Inlet Diffusion
includes the diffusion flux of species at inlet.
Diffusion Energy Source
(if enabled) includes the effect of enthalpy transport due to species diffusion in the energy equation.
Full Multicomponent Diffusion
enables the full multicomponent diffusion model. See Section
8.9.2 for details.
Thermal Diffusion
enables the thermal diffusion model. See Section
8.9.3 for details.
Stiff Chemistry Solver
enables the calculations for modeling stiff laminar flames. See Section
14.1.7 for details.
KINetics From Reaction Design
enables use of reaction rates-of-production from Reaction Design's KINetics module, coupled to
FLUENT's ISAT algorithm.
Mixture Properties
contains controls and information about the mixture being modeled. This section of the panel will not appear if
Premixed Combustion is the selected under
Model.
Mixture Material
contains a drop-down list of available mixture materials. When you first enable the
Species Transport model, you can choose from all of the mixture materials defined in the database, or you can choose a "template'' and define your own material. (Click
Edit... to check the properties of the mixture material selected in the list.) See Section
14.1.3 for details.
When you use the
Non-Premixed Combustion or
Partially Premixed Combustion model, this list will be inactive. The mixture material for a non-premixed or partially premixed combustion calculation will be determined from the content of the PDF file generated in
FLUENT using the
PDF Options parameters.
Number of Volumetric Species
displays the number of gas-phase species in the selected
Mixture Material. This is an informational display only; you cannot edit this value.
Number of Solid Species
displays the number of solid species defined in the selected
Mixture Material. This is an informational display only; you cannot edit this value. (This list will appear only for
Species Transport models involving
Wall Surface reactions.)
Number of Site Species
displays the number of site species defined in the selected
Mixture Material. This is an informational display only; you cannot edit this value. (This list will appear only for
Species Transport models involving
Wall Surface reactions.)
Turbulence-Chemistry Interaction
indicates which model is to be used for turbulence-chemistry interaction when the
Species Transport model with
Volumetric reactions is used.
Laminar Finite-Rate
computes only the Arrhenius rate (see Equation
14.1-8) and neglects turbulence-chemistry interaction.
Finite-Rate/Eddy-Dissipation
(for turbulent flows) computes both the Arrhenius rate and the mixing rate and uses the smaller of the two.
Eddy-Dissipation
(for turbulent flows) computes only the mixing rate (see Equations
14.1-26 and
14.1-27).
EDC
(for turbulent flows) models turbulence-chemistry interaction with detailed chemical mechanisms (see Equations
14.1-26 and
14.1-27).
Options
contains parameters related to the EDC model. This section of the panel will appear when
EDC is selected for
Turbulence-Chemistry Interaction.
Flow Iterations Per Chemistry Update
specifies how often
FLUENT will update the chemistry during the calculation. Increasing the number can reduce the computational expense of the chemistry calculations.
Volume Fraction Constant
specifies the value of
in Equation
14.1-29.
Time Scale Constant
specifies the value of
in Equation
14.1-30).
Mixing Model
contains options to specify the method for modeling molecular diffusion. (This section will appear only if
Composition PDF Transport is the selected
Model.) See Section
18.2.3 for details.
Modified Curl
enables the modified curl model for molecular diffusion.
IEM
enables the IEM model for molecular diffusion.
EMST
enables the EMST mixing model for molecular diffusion.
Mixing Constant
specifies the value of the mixing constant
in Equation
18.2-6 and Equation
18.2-8.
PDF Options
contains options related for the non-premixed combustion model. (This section will appear only if
Non-Premixed Combustion or
Partially-Premixed Combustion is the selected
Model.)
Inlet Diffusion
includes the diffusion flux of species at inlet.
Create Table
enables the parameters to create the PDF table. The panel will expand showing the relevant inputs for the PDF table. See Chapter
15 for the details of these items.
Compressibility Effects
can be enabled to account for cases where substantial pressure changes occur in time and/or space when modeling a non-adiabatic system. See Section
15.7.2 for details.
Number of Flow Iterations Per Property Update
specifies how often the density, temperature, and specific heats are updated from the look-up table.
Liquid Micro-Mixing
is used to model liquid reactions. When the
Liquid Micro-Mixing model is invoked,
FLUENT uses the
volume-weighted-mixing-law formula to calculate the density.
Chemistry
contains the parameters to define problem using the chemistry model. See Section
15.7 for details.
Equilibrium
enables the equilibrium chemistry model. See Section
15.7 for details.
Steady Flamelet
enables the steady laminar flamelet model. See Section
15.3 for details.
Unsteady Flamelet
enables the Eulerian unsteady laminar flamelet model.
Diesel Unsteady Flamelet
enables the diesel unsteady laminar flamelet model. See Section
15.8.6 for details.
Adiabatic
enables adiabatic modeling options for the problem.
Non-Adiabatic
enables nonadiabatic modeling options for the problem. See Section
15.2.3 for details.
Operating Pressure
specifies the system operating pressure used to calculate the density using the ideal gas law. See Section
15.7.2 for details.
Options
contains the parameters for the equilibrium chemistry model or the steady laminar flamelet model.
Secondary Stream
includes the secondary inlet stream in the model.
Empirical Fuel Stream
enables parameters to define fuel stream empirically. This option is available only with the full equilibrium chemistry model.
Empirical Secondary Stream
enables parameters to define secondary stream empirically. This option is available only with the full equilibrium chemistry model.
Create Flamelet
enables the button to import the
CHEMKIN mechanism and thermodynamic data, to create a flamelet file. This option is available for the steady flamelet model.
Import Flamelet
enables the parameters to import the existing flamelet in
FLUENT. See Section
15.8 for details. This option is available for the steady flamelet model.
Rich Flammability Limit
contains parameters to define a rich limit on the mixture fraction when the equilibrium chemistry option is used. You will not set these if you have used the empirical definition option for fuel composition. See Section
15.7.5 for details.
Fuel Stream
specifies the rich flammability limit for fuel stream.
Secondary Stream
specifies the rich flammability limit for secondary stream.
Empirical Parameters
allows to define the fuel or secondary stream when the individual species components of the fuel are unknown.
Fuel Lower Calorific Value
specifies the lower calorific value of fuel stream.
Fuel Specific Heat
specifies the specific heat value of fuel stream.
Secondary Lower Calorific Value
specifies the lower calorific value of secondary stream.
Secondary Specific Heat
specifies the specific heat value of secondary stream.
Import CHEMKIN Mechanism...
opens the
Chemkin Mechanism Import panel, in which you can read the chemkin mechanism file and thermodynamic database file in
FLUENT. See Section
15.8 for details.
Import Flamelet File...
opens the
Select File dialog box in which you can select the existing flamelet in
FLUENT.
File Type
contains the toggle buttons for two flamelet file types.
Standard
enables the import of standard format of flamelet file.
Oppdif
enables the import of binary format of flamelet file.
Mixture Fraction Method
contains the three methods of computing the mixture fraction profile along the laminar flamelet.
Drake
calculates the mixture fraction using carbon and hydrogen elements.
Bilger
calculates the mixture fraction using hydrocarbon formula.
Nitrogen
calculates the mixture fraction in terms of nitrogen species.
Import Flamelet File for Restart...
opens the
Select File dialog box in which you can save the existing flamelet in
FLUENT to use when running an existing case.
Thermodynamic Database File Name
specifies a path for the thermodynamic database file to be read.
Boundary
tab contains the list of boundary species and related parameters. This is available only for equilibrium chemistry model. See Section
15.9 for details.
Species
contains the list of the species used in the problem..
Fuel
specifies the fuel species.
Oxid
specifies the oxidizing species.
Second
specifies the secondary species.
List Available Species
prints a list of all species in the thermodynamic database file ( thermo.db) in the console window.
Species Units
allows to define the unit of species concentration.
Mass Fraction
allows to specify the species in terms of mass fraction.
Mole Fraction
allows to specify the species in terms of mole fraction.
Temperature
specifies the temperature of different streams that you have defined.
Fuel
is the temperature of the fuel inlet in the model.
Oxid
is the temperature of the oxidizer inlet in the model.
Second
is the temperature of the secondary stream inlet in the model.
Boundary Species
allows to specify the species you want to add or remove from the model. You can type the species chemical formula in the text box below it.
Add
adds the species in the model.
Remove
removes the species from the model.
Control
tab contains the parameters for exclusion and inclusion of equilibrium species. This is available only for equilibrium chemistry model. See Section
15.10.1 for details.
Species Excluded from Equilibrium
lists the species excluded from equilibrium calculation.
Species Zeroed in Initial Unsteady Flamelet
lists the slow-forming species that are zeroed in the initial flamelet profile.
Add
allows to add equilibrium species.
Remove
allows to remove equilibrium species.
List Available Species
prints a list of all species in the thermodynamic database file in the console window.
Flamelet Controls
allows you to adjust the controls for the flamelet solution. Note that the
Create Flamelet option in the
Chemistry tab must be selected for the
Steady Flamelet model for these controls to be available.
Initial Fourier Number
sets the first time step for the solution.
Fourier Number Multiplier
increases the time step at subsequent times. Every time step after the first is multiplied by this value.
Relative Error Tolerance and Absolute Error Tolerance
specifies the local error controls during numerical integration.
Flamelet Convergence Tolerance
specifies the maximum absolute change in species fraction or temperature at any discrete mixture-fraction.
Maximum Integration Time
specifies the maximum total elapsed time for flamelet calculation.
FLUENTwill stop the flamelet calculation after the total elapsed time has exceeded this value.
Flamelet
tab allows you to adjust the controls for the flamelet solution. See Section
15.10.2 for details.
Flamelet Parameters
consist of the controls for the flamelet solution.
Number of Grid Points in Flamelet
specifies the number of mixture fraction grid points distributed between the oxidizer (
) and the fuel (
).
Maximum Number of Flamelets
specifies the maximum number of laminar flamelet profiles to be calculated.
Initial Scalar Dissipation
is the scalar dissipation of the first flamelet in the library.
Scalar Dissipation Step
specifies the interval between scalar dissipation values (in s
) for which multiple flamelets will be calculated.
Unsteady Flamelet Parameters
consist of the controls for the unsteady flamelet solution.
Number of Grid Points in Flamelet
specifies the number of mixture fraction grid points distributed between the oxidizer (
) and the fuel (
).
Mixture Fraction Lower Limit for Initial Probability
is the limit at which the unsteady flamelet model temporally convects and diffuses a marker probability equation through a steady-state
FLUENT flow-field.
Maximum Scalar Dissipation
is where flamelets extinguish at large scalar dissipation (mixing) rates.
Courant Number
is the number at which
FLUENT automatically selects the time step for the probability equation based on this convective Courant number.
Calculate Flamelets
begins the laminar flamelet calculation.
Display Flamelets...
opens the
Flamelet 3D Surfaces panel (see Section
15.11.4) from which you can display 2D plots and 3D surfaces showing the variation of species fraction or temperature with the mean mixture fraction or scalar dissipation.
Initialize Unsteady Flamelet Probability
initializes the unsteady flamelet and its probability marker equation.
Display Unsteady Flamelet...
opens the
Flamelet 2D Curves panel from which you can display 2D plots of the different variables.
Table tab contains parameters to create the look-up table. See Section
15.12 for details of the items listed below.
Table Parameters
consist of the controls for the lookup table.
Number of Mean Mixture Fraction Points
is the number of discrete values of
at which the look-up tables will be computed.
Number of Secondary Mixture Fraction Points
is the number of discrete values of
at which the look-up tables will be computed. This option is available only when a secondary stream has been defined.
Number of Mixture Fraction Variance Points
is the number of discrete values of
at which the look-up tables will be computed. This option is available only when no secondary stream has been defined.
Maximum Number of Species
is the maximum number of species that will be included in the look-up tables.
Number of Mean Enthalpy Points
is the number of discrete values of enthalpy at which the three-dimensional look-up tables will be computed. This input is required only if you are modeling a non-adiabatic system.
Minimum Temperature
is used to determine the lowest temperature for which the look-up tables are generated (see Figure
15.2.10). This option is available only if you are modeling a non-adiabatic system.
Include Equilibrium Flamelet
specifies that an equilibrium flamelet (i.e.,
) will be generated in
FLUENT and appended to the flamelet library before the PDF table is calculated. This option is available only when you are generating more than one laminar flamelet.
Calculate PDF Table
generates the look-up table.
Display PDF Table
opens the
PDF Table panel where you can display 2D plots and 3D surfaces showing the variation of species mole fraction, density, or temperature with the mean mixture fraction, mixture fraction variance, or enthalpy.
Premixed contains parameters needed to modify the piecewise-linear points. See Section
17.3.2 for the details.
Partially Premixed Mixture Properties
contains the list of properties that you can modify.
Edit... opens the
Quadratic Mixture Fraction panel where you can modify the values of the polynomial coefficients.
For each polynomial function of
under
Partially Premixed Mixture Properties you can click
Edit... and specify values for
Coefficient 1,
Coefficient 2,
Coefficient 3, and
Coefficient 4 in the appropriate
Quadratic of Mixture Fraction panel.
Integration Parameters Panel
The
Integration Parameters panel allows you to set the parameters for the integration of the chemical source term
in Equation
18.2-10. See Section
18.3.2 for details.
Integration Method
contains options to choose the method for integration.
ISAT
enables the ISAT option and expands the panel to include inputs for ISAT parameters.
Direct Integration
enables the direct integration method to integrate the chemical source term in the calculation.
ODE Parameters
contains options to specify the error tolerances.
Absolute Error Tolerance
specifies the absolute error tolerance.
Relative Error Tolerance
specifies the relative error tolerance.
Integration parameters
contains inputs required for ISAT integration method.
ISAT Error Tolerance
controls the numerical error in ISAT liner interpolation. Decrease this value to get accurate minor species and pollutant predictions.
Max. Storage
is the maximum RAM used by the ISAT table, and has a default value is 100 MB.
Reference Time Step
specifies the time step size by which the ISAT table is normalized.
Number of Trees
specifies the number of sub-tables within the ISAT table.
Verbosity
specifies the level of detail at which you can monitor the ISAT performance.
Clear ISAT Table
purges the ISAT table.
Chemkin Mechanism Import Panel
The
Chemkin Mechanism Import panel allows you to read the chemical kinetic mechanism and thermodynamic data. See Section
15.8 for details on the items listed below.
Gas-Phase CHEMKIN
contains parameters to import the gas phase chemkin mechanism.
Gas-Phase CHEMKIN Mechanism File
specifies the path of the Chemkin file to be read.
Gas-Phase Thermodynamic Database File
specifies the location of the thermodynamic database.
Import Surface Chemkin Mechanism
enables parameters to import the surface chemkin mechanism.
Import Transport Property Databases
(optional) allows to import transport properties.
Flamelet 3D Surfaces Panel
The
Flamelet 3D Surfaces panel allows you to display 2D plots and 3D surfaces showing the variation of species fraction or temperature with the mean mixture fraction or scalar dissipation. See Section
15.11.4 for details.
Flamelet Type
indicates the type of flamelets whose surfaces will be displayed.
Plot Variable
enables you to choose temperature or species fraction as the variable to be plotted.
Plot Type
consists of options for plot type.
3D Surface
enables plotting on 3D surfaces.
2D curve on 3D surface
enables plotting of a 2D curve on a 3D surface.
Options
consists of the following parameters:
Draw Numbers Box
enables the display of a wireframe box with the numerical limits in each coordinate direction.
Write To File
enables saving the plot data to a file.
Curve Parameters
consists of controls related to plot display.
X-Axis Function
consists of the function against which the plot variable will be displayed.
Scalar Dissipation
enables display of plot variable against the scalar dissipation function.
Mixture Fraction
enables display of plot variable against the mixture fraction.
Constant Value of Scalar Dissipation
consists of the controls to specify the type of discretization (i.e., how the flamelet data will be sliced) for the variable that is being held constant.
Slice by
consists of the controls to specify discretization.
Index
enables you to specify discretization index of the variable that is being held constant.
Value
enables you to specify the numerical value of the variable that is being held constant.
Index
consists of the controls that are displayed when you enable
Index under
Slice by.
Index #
displays the index number.
Min
displays the minimum of the range of integer values that you are allowed to choose from.
Max
displays the maximum of the range of integer values that you are allowed to choose from.
Value
consists of the controls that are displayed when you enable
Value under
Slice by.
Value
enables you to enter the numerical value of the variable that is being held constant.
Min
displays the minimum of the range of integer values that you are allowed to choose from.
Max
displays the minimum of the range of integer values that you are allowed to choose from.
Flamelet 2D Curves Panel
The
Flamelet 2D Curves panel allows you to display or write 2D curves of the unsteady flamelet. See Section
15.11.4 for details.
Options
gives you the option to plot or
Write to File 2D curves.
Plot Variable
consists of a drop-down list of variables that you can plot or write.
Plot
is a available by default. When the
Write to File option is enabled the
Plot button changes to a
Write....