Setting Solver Parameters and Stopping Criteria

As the analysis is now unsteady, the time-step size is specified. For the specified rotational speed of 2000 rpm, it takes 0.03 s to complete one full revolution.

In a typical case, it is suggested to use 1 degree per time-step. This setting gives a time-step size of 0.03s/360 or 8.33E-5 s. For demonstration purposes, you solve three solution cycles only, which is 0.09 s.
  1. Edit the Solvers node and set the following properties:
    Node Property Setting
    Implicit Unsteady Time-Step 8.333e-5 s
    Temporal Discretization 2nd-order
    Segregated Flow > Velocity Under-Relaxation Factor 0.8
    Segregated Flow > Pressure Under-Relaxation Factor 0.2
You can specify the maximum physical time to be 0.09 s. The maximum inner iterations value must be selected carefully: if the value is too low, the solution does not converge within a time-step; if it is too high the solution takes a long time to complete. Select a value of 7 and add a runtime monitor later by which you can confirm convergence within a time-step.
  1. Edit the Stopping Criteria node and set the following properties:
    Node Property Setting
    Maximum Physical Time Enabled Activated
    Maximum Physical Time 0.09 s
    Maximum Inner Iterations Maximum Inner Iterations 7
    Maximum Steps Enabled Deactivated
  2. Save the simulation.