Generating the FGM Table

You import the chemistry definition using Chemkin files, and build the FGM table in Simcenter STAR-CCM+.

To generate the FGM table:
  1. Right-click the Continua > Physics 1 > FGM Table Generator > Table Chemistry Definition node and select Import Chemistry Definition (Chemkin format).
  2. In the Import Chemkin Files dialog:
    1. Deactivate Import Transport Properties File.
    2. Import the Chemkin and Thermo Data files that are specified in the table below from :
      Chemical Mechanism File CK_2016-12-14: sandiego20161214_mechCK.txt
      Thermodynamic Properties File THERM_2016-08-15: sandiego20160815_therm.txt
    3. Click OK.
    The Output window confirms that the files and species are imported successfully, and the Chemistry Definition > Reactions node is populated with all of the reactions in the mechanism.
Before generating the FGM library and constructing the FGM table, you define the premixed mixture fraction in the fuel stream and specify the number of grid points for mixture fraction and mixture fraction variance.
  1. Expand the FGM Table Generator > Fluid Streams node and set the following properties:
    Node Property Setting
    Fuel Fluid Stream Components C3H8, 0.0369
    N2, 0.7416
    O2, 0.2215
    Temperature 600 K
    The FGM Table Generator > Reactor Type is set to 0D Ignition by default. For this tutorial, we maintain the 0D reactor as it is faster to generate than the 1D reactor. However, the turbulent premixed flames in this tutorial are better suited to the 1D reactor.
  2. Select the FGM Table Generator > Parameters > Species For Tabulation node and using the (custom editor), in addition to the species that are previously selected, add CO and OH.
For perfectly premixed systems, the equivalence ratio and mixture fraction are constant. Consequently, there are no fluctuations in mixture fraction, and the variance is zero. You can create a significantly smaller flamelet table by forcing the number of mixture fraction points to 2 (the minimum), where one stream—in this case, the fuel stream—is set to the premixed composition. Also, you set the number of mixture fraction variance points to 1.
  1. Edit the FGM Table Generator > Parameters > OD Ignition Numerical Settings > Table Dimensions node and set the following properties:
    Node Property Setting
    Mixture Fraction Use Adaptive Number of Grid Points Deactivate
    Number of Grid Points 2
    Mixture Fraction Variance Use Adaptive Number of Grid Points Deactivate
    Number of Grid Points 1
  2. Right-click the FGM Table Generator > FGM Table node and select Generate FGM Library and Construct Table.
    The Output window updates with the progress of the table generation. When complete, the species appear under the Continua > Models > Multi-Component Gas > Gas Components node.
  3. Save the simulation.