General

General

How to skip over the flow and adjoint iterations for the first design iteration when using the Ansys Fluent Gradient-Based Optimizer?

    • SolutionSolution
      Participant

      If you have an existing solution from the flow and/or the adjoint calculation, you might want to skip over the initial calculations when starting the automated optimization process with the gradient-based optimizer for shape or turbulence model optimization. In the optimizer, you can simply set the number of iterations to zero for both calculations. Then access the Execute Commands… either from the Gradient-Based Optimizer window, or from the ribbon Design > Gradient-based > Calculate… > Calculation Activities > Execute Commands… Add one or two new commands with the lines: /adjoint/optimizer/settings/adjoint-iterations 20 /adjoint/optimizer/settings/flow-iterations 200 Adjust the numbers in these lines according to your calculation requirements. You must execute this repeatedly. “Execute Once” is not supported for design iterations. When you start the optimization now, Fluent reports a warning that the number of iterations is insufficient. You can just acknowledge that message and continue. The optimization process starts with the design calculation and continues with saving the optimal design. Before starting the flow calculation, it executes the text commands that set the maximum number of iterations to the intended values. Remember that if you continue an optimization, you can skip the flow but not the adjoint calculation.

      Attachments:
      1. 2068754_adjoint_skip_flow_calculation.mp4
      2. 2068754_adjoint_skip_flow_calculation.pdf