Steady Laminar Flamelet Table Reference

This section describes the parameters that you set for the SLF Table which the Steady Laminar Flamelet model uses.

SLF Table Generator

Properties
None
Right-Click Actions
Import Table…
Imports a previously saved SLF table.
注Since tables are saved in single precision, Table Precision—under the SLF Table Generator > Parameters node—is switched to Single after importing a table.
Delete Table
Removes a stored table from memory. The flamelet table must be deleted before making changes to the table settings.
Stop Calculations
Stops the calculations during the flamelet library generation.
Child Nodes
The SLF Table Generator node contains the following sub-nodes:

Chemistry Definition

The Chemistry Definition describes the chemical reaction mechanism, which is the collection of all species in a reaction—reactants, intermediates, and products—and the corresponding set of all reactions. The Chemistry Definition also includes the thermodynamic properties, as well as, optionally, the transport properties.
Properties
None
Right-Click Actions
Import Complex Chemistry Definition (Chemkin format)
Activates a standard Open dialog that imports a library file for the complex chemistry definition in Chemkin™ format. Upon importing a chemistry definition, the reactions for the definition appear as sub-nodes of the Chemistry Definition node.
If you import transport data along with the chemical mechanism and thermal data, Simcenter STAR-CCM+ tabulates the molecular transport properties for the Dynamic Viscosity, Molecular Diffusivity, and Thermal Conductivity material properties. You can then choose to use these tabulated molecular transport properties after table generation, in the Multi-Component Gas node, by selecting the Flamelet Table option for each of the Material Properties.
Delete Complex Chemistry Definition
Removes the species and the corresponding reactions from the chemistry definition.

Parameters

Properties
Table Precision
Specifies the precision—Single or Double—to which the flamelet table is generated. The default is Single.
Child Nodes
Absolute Pressure
Value: The pressure that is used when generating the flamelet table.
Species for Tabulation
Species: Allows you to select which species are stored in the flamelet table. These species are then made available in a simulation, for example, to use for post-processing in contours or reports.
Emissions
Thermal NOx
When activated, the NOx source-term coefficients are calculated and tabulated.
Soot Moment
When activated, the soot moment model source-term coefficients are calculated and tabulated. Creates a Soot Moments Options sub-node which allows you to specify the Nucleation Option as either:
  • C2H2, see Eqn. (3682).
  • Single PAH Species (C16H10), see Eqn. (3679) and Eqn. (3680). The PAH precursor is recognised as any species which includes either A4 or A3R5 in the species name, or has the composition C16H10.
Numerical Settings
The Numerical Settings node allows you to define the following properties. It also contains the Table Dimensions sub-node which you can use to define the dimensions for the flamelet table. See Table Dimensions Reference.
  • Absolute Tolerance: Specifies the absolute tolerance of the ODE solver.
  • Relative Tolerance: Specifies the relative tolerance of the ODE solver.
  • Flamelet Relative Tolerance: The flamelet equations are integrated in time using the ODE solver Absolute Tolerance and Relative Tolerance until steady-state. Steady state is determined when the average residual over all species and temperature and all grid points is less than the Flamelet Relative Tolerance.
  • Initial Scalar Dissipation (/s): Specifies the scalar dissipation rate, χ in Eqn. (3346), for the first steady laminar flamelet.
  • Maximum Scalar Dissipation (/s): Specifies the largest scalar dissipation, χ in Eqn. (3346), that is allowed. Usually, flamelets extinguish well before this value. See Scalar Dissipation Rate.
  • Scalar Dissipation Multiplier: The sequence of flamelet scalar dissipation rates are calculated as follows: Starting from the initial scalar dissipation rate, the next scalar dissipation is multiplied by 10/s (if the current scalar dissipation is less than 1/s). Else it is multiplied by the scalar dissipation multiplier, until either the flamelet extinguishes or else the maximum scalar dissipation rate is exceeded. See Scalar Dissipation Rate.

SLF Table

Properties
Save Table in .sim File
When activated, stores the flamelet table in the sim file. When deactivated, the flamelet table is not stored in the .sim file—which is useful to save disk space when using the same flamelet table in different .sim files, or when auto-saving many sim files. If the flamelet table is required for future use, you must export it manually by right-clicking the flamelet table node and selecting Export Table. Then save it separately from the .sim file.
Path for Table Read
Specifies the file path location of the flamelet table file that has been exported from Simcenter STAR-CCM+ and saved previously. Useful to reduce the .sim file size and save disk space when several .sim files use the same flamelet table.
Verbosity
When activated, if selected tolerance criteria are not met in adaptive grid generation steps, Simcenter STAR-CCM+ prints a summary of tolerance warnings to the Output window at each step during the table generation.
For example:
WARNING: For 'Heat Loss Ratio' the   maximum error of 0.00652988 is greater than the specified tolerance of 0.0001. To achieve the prescribed tolerance, delete the table, increase the maximum number of points (currently 9) and regenerate the table.
When deactivated, all of the warning messages about exceeding the defined tolerance for adaptive table dimensions are hidden.
Right-Click Actions
Generate Flamelet Library and Construct Table
Generates steady laminar flamelet libraries and constructs the presumed probability density function (PPDF) table.
Print Estimated Maximum Table Size
Prints the estimated maximum table size (in KB) in the output window. This value also appears as a read-only property of the Table Dimensions node.
Export Table

Saves a table that is stored in the memory of Simcenter STAR-CCM+ to a file with extension .tbl.

Delete Table
Removes a stored table from memory. The flamelet table must be deleted before making changes to the table settings.
Stop Calculations
Stops the calculations during the flamelet library generation.
Print Table Summary
The Output window displays a summary of the table parameters and conditions with which the table was built. When running the simulation, if the current parameters and conditions differ from those that were specified when the table was built, a warning is displayed in the Output window at each iteration.
Parameters and conditions are not displayed for tables that are imported from Simcenter STAR-CCM+ versions prior to 2406, or from tables that are constructed using DARS libraries.
Child Nodes
Final Table Grid Size
Contains sub-nodes for each of the table dimensions. Each table dimensions sub-node displays the read only value, Number of Grid Points, that are used from the data for that parameter. The values are specified before building the table by defining settings under the Table Dimensions node. See Table Dimensions Reference.
SLF XY Plots
To visualize the steady laminar flamelet table, you can create an XY plot—right-click this node and select New Plot. See Flamelet Table XY Plots Reference.