Hello,

I am trying to find the steady-state solution of a flexible kite using FEM with dynamic relaxation for the structure and a panel method for the fluid. Both codes are static, which means no real time stepping is involved.

So far I get good results using the constant relaxation which converges after approximately 15 coupling iterations depending on the relaxation parameter. Nevertheless, I would like to accelerate the convergence a bit but so far have not been successful getting a converged solution running different acceleration methods.

I have tried the Aitken acceleration with a range of initial relaxation values, but the coupling always diverges after a few coupling iterations. In the preCICE manual it says that in case the Aitken does not converge a QN method could be better. I also tried IQN-ILS without success and I am a bit clueless whether I have to use time stepping or if QN methods do not apply to steady-state FSI in the first place.

Any advice from you side?

Best regards,

Paul

P.S. I am running an older version of preCICE at the moment (Version 1.4.1)

preCICE.xml (4.7 KB)