For certain two-way thermal and FSI coupled analyses, convergence instabilities can be addressed with System Coupling's Quasi-Newton solution stabilization and acceleration method.

Quasi-Newton stabilization, which is based on the Interface Quasi-Newton – Inverse Least Squares (IQN-ILS)[1] algorithm, can be used to address convergence issues in coupled analyses run in one of System Coupling's user interfaces. It can improve convergence by applying an approximate Newton iteration to the coupling interface data.

For more detailed information, see Quasi-Newton Stabilization Algorithm.