Interphase Reactions Workflow: Multiphase

When defining reactions within an Eulerian phase, you can include species from the Particle or Gas models within a different Eulerian phase that is specified within the same phase interaction.

The steps in this workflow are intended to follow on from the initial steps in the Reacting Flow General Workflow.
  1. For the Physics Continuum that represents the background phase in which the Eulerian phase reactions occur (the continuous phase), select the following models. Maintain the existing model selections and make sure that Auto-Select recommended models is activated.
    Group Box Model
    Multiphase Model Select either:
    • Eulerian Multiphase (EMP)
    • Volume of Fluid (VOF)
    • Mixture Multiphase (MMP)
    Optional Models Phase Coupled Fluid Energy (available when Eulerian Multiphase (EMP) is selected) Segregated Multiphase Temperature (available when Volume of Fluid (VOF) or Mixture Multiphase (MMP) is selected)
  2. Select any further optional models as necessary.
  3. Under the Multiphase model node, create and define the Eulerian phases using the following guidance on model selection (along with any other models that are required).
    For interphase combustion simulations, create at least two phases.
    Group Box Model
    Material For Eulerian phases which participate in reactions, select one of:
    • Multi-Component Gas
    • Multi-Component Liquid (required for multiphase polymerization)
    • Multi-Component Particle
    Energy Segregated Fluid Enthalpy or Segregated Fluid Temperature (available for Eulerian Multiphase (EMP) Eulerian phases only)
    Reaction Regime
    • For phases in which intraphase reactions occur, select Reacting (required for multiphase polymerization)
    • For any other phases, select Non-Reacting
    Reacting Flow Models Reacting Species Transport
    Reacting Species Models
    • When using large reaction mechanisms that are imported in the standard format, select Complex Chemistry
    • When using small mechanisms that are defined in the GUI with four steps or less, select Eddy Break-Up
    • For multiphase polymerization, select Polymerization
    Equation of State (except when the Complex Chemistry model is selected) any
    Turbulence Chemistry Interactions (when the Complex Chemistry model is selected) Select either:
    • Eddy Dissipation Concept
    • Laminar Flame Concept
    For more information, see Defining Eulerian Phases.
Phase interactions can define reactions between any two phases of Multi-Component Gas, Multi-Component Liquid, or Multi-Component Particle. You can specify any number of phase interactions—each with any number of reactions. However, each phase interaction can only contain two phases. Depending on the multiphase model that you select, the following phase interaction models are available:
  • Continuous Dispersed Phase Interaction (for Eulerian Multiphase (EMP) only)

    Define the phase interaction between the continuous and the dispersed phase. When you create a phase interaction, you select the Continuous Phase first, and then the Dispersed Phase. When you select the dispersed phase, you also choose the phase interaction type.

  • Multiple Flow Regime Phase Interaction (for Eulerian Multiphase (EMP) only)
  • VOF-VOF Phase Interaction (for Volume of Fluid (VOF) only)
  • MMP-MMP Phase Interaction (for Mixture Multiphase (MMP) only)

    Define the phase interaction between the primary phase and the secondary phase. You select the Primary Phase first, and then the Secondary Phase. When you select the secondary phase, you also choose the phase interaction type.

Create and define the phase interactions.

  1. Right-click the Models > Multiphase Interaction > Phase Interactions node and set the appropriate phase interactions.
    Phase Interaction Model
    Continuous Dispersed New > [continuous Phase] > [dispersed Phase] (Continuous-Dispersed)
    Multiple Flow Regime New > [primary phase] > [secondary phase] (Multiple Flow Regime)
    VOF-VOF or MMP-MMP New > [primary phase] > [secondary phase]
    The Phase Interaction 1 node is added under Phase Interactions.
  2. Right-click the [phase interaction] > Models node and click Select Models.
    • For Eulerian Multiphase (EMP), in the Phase Interaction Model Selection dialog, select the following phase interaction models, with Auto-Select recommended models activated:
      Group Box Model
      Optional Models Interphase Mass Transfer
      Interphase Mass Transfer Rate/ Interphase Mass Transfer Models Interphase Reaction
    • For Volume of Fluid (VOF) or Mixture Multiphase (MMP), in the Phase Interaction Model Selection dialog select Interphase Reaction.
  3. Create and define the interphase reactions within each phase interaction. Right-click the Interphase Reaction > Reactions node and select New Reaction.
    You can specify reactant and product species from either of the two phases that are specified for a phase interaction.
    See Modeling Interphase Reactions.
  4. For each component that you want to include in the reaction, right-click the Reactions > [reaction] > Reactants node, click Add Reactant, and then select the component.
  5. For each product of the reaction, right-click the Reactions > Reaction 1 > Products node, click Add Product, and then select the product.
  6. For each reaction component and product, select the component node and, in the Properties window, specify the appropriate values:
    Stoich. Coeff. The stoichiometric coefficient that is appropriate to the reaction.
    Rate Exponent The rate exponent that is appropriate to the reaction.
  7. Select the Properties > Reaction Coefficient node and specify the appropriate reaction rate properties. See, Interphase Reaction Model Reference.
  8. If you are simulating multiphase polymerization, proceed to the Polymerization Workflow.
  9. Return to the Reacting Flow General Workflow.