Dynamic Model Control (see Dynamic Model Control in the CFX-Solver Modeling Guide) is designed to improve robustness during the first several iterations of a simulation.
By selecting the Harmonic Balance Control option (in CFX-Pre, in the Solver Control details view, on the Advanced Options tab, under Dynamic Model Control), you can use a steady state solution approach to suppress the temporal derivative for a number of iterations. The idea is to solve a simpler and more robust model for the first few iterations to obtain a better initial guess for the harmonic balance simulation.
You should use the Harmonic Balance Control option:
If you don't want to create a separate steady-state simulation.
When you need a better initial guess with time-dependent boundary conditions.
If you want to further refine a provided steady state initial guess.
The Convergence Control settings are the same as those found on the Basic Settings tab of the Solver Control details view. For details, see Basic Settings for Steady-State Simulations and for Transient Blade Row Cases that use the Harmonic Balance Transient Method in the CFX-Pre User's Guide.
The Convergence Criteria settings are the same as those found on the Basic Settings tab of the Solver Control details view. For details, see Convergence Criteria in the CFX-Pre User's Guide.
The start of the steady state simulation is marked by a "Steady State Solution" banner
in the CFX-Solver Output file.
After the Harmonic Balance Control convergence criteria are met,
the harmonic balance simulation begins, as marked by a "Harmonic Balance Solution" banner
in the CFX-Solver Output file.