Running the Simulation

You run the unsteady simulation for a physical time of 1.5 s. The adaptive time-step size is limited by a maximum value of 0.0003 s. Adaptive meshing is invoked every other time-step.

In addition to the blob diameter and blob shape criteria, the resolved Eulerian-Lagrangian transition is influenced by two other factors that you set for the Lagrangian Two-Way Coupling solver:
  • Maximum volume fraction—The Resolved Eulerian-Lagrangian Transition model evaluates the Lagrangian volume fraction after the transition and, if the evaluated value does not exceed the specified Maximum Volume Fraction, the VOF blob is converted to a Lagrangian particle. If the evaluated value exceeds the specified Maximum Volume Fraction, the transition does not occur and the VOF blob remains as a resolved VOF phase. For this tutorial, you use the default value of 0.75.
  • Cell clustering—To prevent the Lagrangian water droplet volume fraction from exceeding the specified maximum volume fraction, you use volume cell cluster source smoothing. Cell clustering can be used to avoid the resulting Lagrangian droplet from overwhelming the cell if it is much smaller than the droplet. When the VOF blob is removed, adaptive meshing can coarsen the mesh, and the Lagrangian droplet becomes sub-grid.

To run the simulation:

  1. Select the Solvers > Implicit Unsteady node and set Time-Step to 3.0E-4 s.
  2. Select the Solvers > Adaptive Mesh > Trigger > Time-Step Frequency node and set Frequency to 2.
  3. Select the Lagrangian Multiphase > Two-Way Coupling > Volume Source Smoothing Method node and set Method to Cell Cluster.
  4. Select the Stopping Criteria > Maximum Physical Time node and set Maximum Physical Time to 1.5 s.
  5. Select the Maximum Steps node and deactivate Enabled.
  6. To run the simulation, click (Run).
  7. When the simulation has finished, save it.