Setting Solver Controls and Stopping Criteria

You control the sequence of flow solution, adjoint solution, and surface mesh morphing by setting individual stopping criteria for each solver. A global stopping criterion determines the overall number of shape optimization loops.

The steady-state flow solution runs until either the mass flow at Outlet 1 has stabilized at a nearly constant value or until 200 iterations are complete. For the adjoint solution, you specify a fixed number of 50 iterations after which the mesh operations are executed, including the surface mesh morphing. The simulation stops when 500 iterations are performed.

To enhance convergence, you activate grid sequencing for the coupled solver.

To set solver controls and stopping criteria:

  1. Specify the stopping criterion for the primal flow:
    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 200.
    3. Right-click the Solvers > Steady > Stopping Criteria > New Monitor Criterion... node and select New Monitor Criterion.
    4. In the Select Monitor dialog, choose Mass Flow 1 Monitor, then click OK.
    5. Select the Mass Flow 1 Monitor Criterion node and set Criterion Option to Asymptotic.
    6. Edit the Mass Flow 1 Monitor Criterion > Asymptotic Limit node and set the following properties:
Property Option
|Max-Min| 1.0E-06 kg/s
Number of Samples 20
Normalized Deactivated
  1. To initialize the flow field, select the Solvers > Coupled Implicit > Expert Initialization node and set Method to Grid Sequencing.
  2. Define the adjoint solver settings and stopping criterion:
    1. Right-click the Solvers > Adjoint > Solvers > Adjoint Steady > Stopping Criteria node and select New Montior Criterion > Fixed Steps.
    2. Select the Fixed Steps node and set Fixed Steps to 50.
  3. To specify the global stopping criterion, select the Stopping Criteria > Maximum Steps node and set Fixed Steps to 500.
  4. Save the simulation.