Setting Stopping Criteria

Set the stopping criteria to terminate the simulation after three engine cycles.

As the engine is running at 3000 rpm, each time step is a one degree crank angle rotation. Therefore, for three engine cycles, 2160 time steps are required. However, you run the simulation for a few extra time steps, as rounding errors in the time step duration can cause 720 time steps to be slightly less than a full cycle. When an incomplete cycle occurs, the GT-SUITE solver is stopped prematurely and output files are not generated correctly. Therefore, you use a total of 2162 time steps.

Also, the Simcenter STAR-CCM+ solver runs iterations between time steps to solve the effect of transient boundary conditions. In this case, 5 inner iterations are adequate to guarantee convergence between time-steps.

To set the stopping criteria:

  1. Edit the Stopping Criteria node and set the following properties:
    Node Property Setting
    Maximum Steps Maximum Steps 2162
    Maximum Inner Iterations Maximum Inner Iterations 5
  2. Save the simulation.