Restoring the Premixed Coherent Flame Model

The Premixed Coherent Flame Model (CFM) in Simcenter STAR-CCM+ v.11.06 is restored to the Flamelet Generated Manifold (FGM) model with the Coherent Flame Model (CFM) flame propagation model. You can restore the Premixed model settings as described in this section.

As part of a plan to improve and simplify the procedure for selecting combustion models, the Premixed CFM model is discontinued in Simcenter STAR-CCM+ v.11.06.

When loading a simulation in Simcenter STAR-CCM+ v.11.06 or later that was saved in a version of Simcenter STAR-CCM+ before v11.06, the Premixed CFM model is restored to the Flamelet Generated Manifold (FGM) model with the Coherent Flame Model (CFM) flame propagation model. Several settings are defined differently and must be set up again. The following images show a comparison of the temperatures on the cross section of a flame holder.
Premixed CFM 11.04


Premixed FGM 11.06 (Partially Pre-Mixed)


Simcenter STAR-CCM+ v.11.06 provides the FGM model as an option for Premixed Combustion. However, this model is the same as that provided for Partially-Premixed combustion. Further steps are required to restore the premixed behaviour that was available in Simcenter STAR-CCM+ v.11.04 and earlier. These steps are as follows:

You can restore the settings of the deprecated Premixed combustion model, using the following procedure:
  1. Redefine the reacting fluid stream to match the Premixed set-up.
    1. Select the [Continuum] > FGM Table Generator > Fluid Streams node and set the Fluid Stream Components as the Premixed mixture.
    2. Select the Fluid Streams node and set the Temperature of the Stream using the temperature from Simcenter STAR-CCM+ v11.04 that is set for the inlet boundary of the fuel/air mixture.
    3. Select the [Continuum] > FGM Table Generator > Fluid Streams > Oxidizer Stream node and set the Fluid Stream Components as Air.
    4. Select the Oxidizer Stream node and set the Temperature of the Stream using the temperature from Simcenter STAR-CCM+ v11.04 that is set for the inlet boundary of the fuel/air mixture.
Any FGM Table parameters that were set in the simulation before Simcenter STAR-CCM+ v11.06, must be redefined.
  1. Create an FGM table using [Continuum] > FGM Table Generator.
    • Set the Fuel Composition to the premixed mixture and the oxidizer to air.
    • Set the Fuel Temperature to the temperature that is set for the inlet boundary of the fuel/air mixture in Simcenter STAR-CCM+ v11.04.
    • Set the Pressure to the absolute pressure that is specified in Simcenter STAR-CCM+.
  2. Select the [Physics] > Initial Conditions > Mixture Fraction Profile node and specify the Value as 1.0.
  3. Select the Models > Flamelet Generated Manifold > Progress Variable Variance node and set the Method that you require.
  4. To restore the Ignitor:
    1. Right-click the [Continuum] > Ignitors node and select New.
    2. Select the ProgressVariableIgnitor 1 node and specify the necessary properties.
    3. If the ProgressVariableIgnitor 1 node Activator is set to Pulse, select the Pulse sub-node and specify the necessary properties.
  5. For all inlet and outlet boundaries within each physics continuum, select the [Boundary] > Physics Values > Mixture Fraction Profile node and specify the Value as 1.0.