OpenFOAM-CalculiX FSI unable to converge

Hi everyone!

I am a newbie using preCICE. I am trying to implement a simple 2D wing simulation by changing the perpendicular-flap case in the tutorial, referring to the OpenFOAM tutorial Turbulent flow over NACA0012 airfoil (2D) and assume that the Solid-part front-end is fixed for the FSI simulation.

The results do not to be converging

---[precice] ERROR:  Attempting to add a zero vector to the quasi-Newton V matrix. This means that the residuals in two consecutive iterations are identical. If a relative convergence limit was selected, consider increasing the convergence threshold.

Do I have any missing or improper settings?

I have attached the file I set up here Cases

I am stuck and any help would be really appreciated

Best regards,


P.S. I am running preCICE version 2.5.0

Does this happen in the first coupling time window, or later on?

It happens in the first time window

There are currently some related known issues with zero coupling data in the first time window:

They are both currently scheduled for preCICE v3.0.0 (but this is no guarantee).

In any case, as a general rule-of-thumb for FSI simulations, it is helpful to start from a precomputed flow field (i.e., a few seconds simulated without coupling). Unless, of course, the zero initial conditions are particularly important for your application.