Polymerization Workflow

Polymerization processes involve various chemical reactions during which monomer molecules combine to form polymer chains. These processes require the reacting species transport physics model in Simcenter STAR-CCM+.

The steps in this workflow are intended to follow on from the Reacting Flow General Workflow (or, where applicable, from Interphase Workflow: Multiphase).
  1. For the physics continuum (or Eulerian phase) that represents the reacting flow, select the following models—in addition to the models that are previously selected, with Auto-select recommended models activated:
    Group Box Model
    Enabled Models Reacting Species Transport (selected automatically when following the Reacting Flow General Workflow)
    Reacting Species Models Polymerization
  2. Select any Optional models that are also required.
The process of polymerization is comprised of several sub-reactions which include free radical polymer reactions. Free radicals are small, charged molecules that react with monomers and create charged monomers. The charged monomers then combine with other monomers and form a polymer chain. Throughout the polymerization process, free radical polymer reactions consume and create free radicals at different rates. In Simcenter STAR-CCM+, you can specify which free radical polymer reactions occur and define the rates.
  1. Set the free-radical polymer reaction properties.
    1. Expand the [Continuum] > Models > Polymerization > Free-Radical Polymer Reactions node.
    2. To define the reaction rate for a free-radical polymer reaction, select the required free-radical polymer reaction sub-node and set the Method that you require as a scalar profile.
    3. Define the Unit System property appropriate to the reaction.
    4. If you do not wish to specify the reaction rate for any of the free-radical polymer reactions, select the relevant sub-node and:
      • Set the Method property for the sub-node to Constant.
      • Set Value to 0.0.
The Polymer Scalars and Polymer Moments sub-nodes allow you to specify User Rate and User Rate Jacobian source terms directly to the Polymer Scalar and Polymer Moment equations.
  1. If you intend to specify User Rate or User Rate Jacobian source terms:
    1. Select the Polymerization node and activate the property, User Rates.
      The Polymer Scalars and Polymer Moments sub-nodes become populated.
    2. Set the User Rate and / or User Rate Jacobian values for the Polymer Scalars and Polymer Moments as required.
  2. Set the remaining Polymerization model Properties as required.
    See: Polymerization Model Reference.
  3. Specify the Liquid Components and Material Properties of the Multi-Component Liquid.
    1. Right-click the [Continuum] > Models > Multi-Component Liquid > Liquid Components node and select one of the following options:
      • Import Species.

        In the dialog that appears, Browse to and select the file which contains the monomer species that you are importing.

      • Select Mixture Components.

        Browse the Standard Materials Database that appears and select the liquid components that represent the monomers. Click Apply then Close.

      For more information, see Managing Mixture Components.
    2. Expand the Multi-Component Liquid > Liquid Components node and define the material properties as required.
      For more information, see Setting Material Properties Methods.
  4. Set the parameters of any other [Continuum] > Models, as required.
  5. For the continuum, define any necessary parameters for the Reference Values and Initial Conditons.
    Set the Initial Condition concentrations for the Polymer Initiator, Polymer Monomer, Polymer Radical, Polymer Solvent, andPolymer Modifier scalars.
  6. Define any necessary Physics Conditions and Values for the Region and Boundaries.
    For the Inlet boundaries, expand the Physics Values node and set concentrations for the Polymer Initiator, Polymer Monomer, Polymer Radical, Polymer Solvent, andPolymer Modifier using scalar array profiles.
  7. If necessary, set up Injectors. For example, if any of the polymerization reaction components are injected into the domain.
    See: Working With Injectors.
  8. Return to the Reacting Flow General Workflow.