Setting Solver Controls and Stopping Criteria

For this simulation, the coupled implicit solver is set to run with automatic CFL control. The primal solver is set to run for 300 iterations by applying solver-specific stopping criteria. The adjoint solver is set to run for 150 iterations for each optimization loop.

To set the coupled solver controls:
  1. Select the Solvers > Coupled Implicit node and set the following properties:
    Node Property Setting
    Coupled Implicit CFL Control Method Automatic
    Explicit Relaxation Method Constant
    Constant Relaxation Explicit Relaxation 0.3
To add a steady solver stopping criterion to control the primal run:
  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 300.
    The steady coupled solver stops after running 300 iterations.
  3. To omit the maximum steps stopping criterion, select the Stopping Criteria > Maximum Steps node and deactivate Enabled.
You have two options to set adjoint stopping criteria:
  • Specify stopping criteria within a cost function—under the Adjoint > Adjoint Cost Functions > [cost function] > Stopping Criteria node. With this option, you can run various cost functions with different numbers of steps.
  • Specify a general stopping criteria for all the cost functions—under the Adjoint > Solvers > Adjoint Steady > Stopping Criteria node. With this option, all the cost functions are controlled with the same numbers of steps.

To define a general adjoint solver stopping criterion for the only one cost function:

  1. Right-click the Solvers > Adjoint > Solvers > Adjoint Steady > Stopping Criteria node and select New Criterion > Fixed Steps.
  2. Select the Fixed Steps node and set Fixed Steps to 150.
To deactivate the cost function-specific stopping criteria:
  1. Select the [cost function] > Stopping Criteria > Fixed Steps node and deactivate Enabled.
  2. When the solver settings are finished, save the simulation.