Modeling the Transition of Free-Stream Droplets to Wall-Bound Droplets

To model free-stream droplets impinging on a wall, then sticking and sliding as wall-bound droplets, you create a Lagrangian-Lagrangian phase interaction that handles the conversion of free-stream droplet type to wall-bound droplet type.

To set up the transition of free-stream droplets to wall-bound droplets:

  1. Right-click the [continuous phase physics continuum] > Models > Multiphase Interaction > Phase Interactions node and select New > [free-stream phase] > [wall-bound phase] or New > [wall-bound phase] > [free-stream phase].
    The Lagrangian-Lagrangian Phase Interaction model is created under the Phase Interactions > [phase interaction] > Models node. Depending on the order in which you select the phase pair, the read-only First Lagrangian Phase and the Second Lagrangian Phase are determined.
  2. Right-click the [phase interaction] > Models node and, from the Optional Models group box, select Deposition. See Deposition Model Reference.
    The Deposition model handles the transition of the free-stream to the wall-bound droplets droplets.
    The Deposition model automatically creates a parcel transfer injector under Injectors > [free-stream phase] to [wall-bound phase] that manages the creation and initialization of the wall-bound droplets.
  3. Select the Injectors > [free-stream phase] to [wall-bound phase] node and set the following properties:
    Property Setting
    Lagrangian Phase Select the [wall-bound phase]. The wall-bound phase is the phase that is generated by this parcel transfer injector.
    Inputs Select the [free-stream phase]. The free-stream phase is the source phase from which the wall-bound phase is generated.
    The droplet transition takes place when a free-stream droplet interacts with a wall boundary. You are not required to specify a transfer condition, and therefore Method under Values > Transfer Criterion is set to Model Driven.
  4. Define the interaction of the free-stream droplet with the wall boundary:
    1. Expand the [continuous phase physics continuum] > Models > Lagrangian Multiphase > Lagrangian Phases > [free-stream phase] node.
    2. Select the Boundary Conditions > Fluid-Film Boundary > Physics Conditions > Mode node and set Active Mode to Transfer To Wall-Bound Phase.