Setting Stopping Criteria

Set the maximum physical time and create an additional stopping criterion from the temperature point monitor.

In this tutorial, the co-simulation converges within 40 time steps, so use the maximum physical time to impose this limit:

  1. Select the Stopping Criteria > Maximum Physical Time node and set Maximum Physical Time to 10000 s.
NoteNote: the maximum physical time does not need to match the Time Period setting in Abaqus. During the co-simulation, you can terminate the run using either application, depending on your specified stopping criteria.

In the early stages of the simulation, you can expect the number of inner iterations Simcenter STAR-CCM+ requires to be much higher, since Simcenter STAR-CCM+ is effectively solving the initial steady-state solution in the fluid. However, as the simulation progresses, the number of inner iterations per time step reduces, as the solution converges much more quickly. To accelerate the progress of the co-simulation, either decrease the number of inner iterations manually (by observing the temperature monitor and adjusting the Maximum Inner Iterations stopping criterion) or use an additional stopping criterion. The latter technique is described.

Create a stopping criterion from a temperature monitor such that when the temperature solution has converged for each time step, Simcenter STAR-CCM+ stops iterating. Increase the number of iterations for the Maximum Inner Iterations stopping criterion so that enough iterations are carried out in the initial steps:

  1. Copy the Monitors > Temperature Point Monitor node and paste it onto the Monitors node.
  2. Rename Temperature Point Monitor copy to Temperature Point Monitor_Iteration.
  3. Select the Temperature Point Monitor_Iteration node and set Trigger to Iteration.
  4. Right-click the Temperature Point Monitor_Iteration node and select Create Stopping Criterion from Monitor.
    A new node named Temperature Point Monitor_Iteration Criterion is created under the Stopping Criteria node.

The temperature solution can be said to have converged when the temperature variations per iteration have dropped below 0.05 K. To specify an asymptotic stopping criterion:

  1. Edit the Stopping Criteria node and set the following properties:
    Node Property Setting
    Maximum Inner Iterations Maximum Inner Iterations 60
    Temperature Point Monitor_Iteration Criterion Criterion Option Asymptotic
    Asymptotic Limit Normalized Deactivated
    |Max-Min| 0.05 K
  2. Save the simulation.