Specifying Steady and Unsteady Solution Controls

In this multi-timescale simulation the steady solver and the implicit unsteady solver are run alternately. You define one stopping criterion for each solver as well as a global stopping criterion.

To specify steady and unsteady solution controls:

  1. For the steady solver:
    1. Right-click the Solvers > Steady > Stopping Criteria node and select New Criterion > Fixed Steps .
    2. Select the Fixed Steps node and set Fixed Steps to 250.
      This criterion defines the length of the steady run between mapping steps.
  2. For the implicit unsteady solver:
    1. Select the Solvers > Implicit Unsteady node and set Time-Step to 0.2 s.
    2. Right-click the Solvers > Implicit Unsteady > Stopping Criteria node and create the following criteria:
      Node Property Setting
      Fixed Physical Time Fixed Physical Time 50.0 s
      Maximum Inner Iterations Maximum Inner Iterations 4
      These criteria define the cycle length of the unsteady run between the mapping steps.
  3. Expand the global Stopping Criteria node:
    1. Delete the Maximum Inner Iterations node.
    2. Delete the Maximum Steps node.
    3. Select the Maximum Physical Time node and set Maximum Physical Time to 500 s.
      This value specifies that the unsteady run of the Manifold (Thermal) continuum stops at 500 s.