FSI: OpenFOAM adapter with interFOAM

Unfortunately, the simulation diverge after time 0.5[s].
Moreover, the max Courant number is very low except that in water collision against the wall (more or less at time 0.2[s] to 0.26[s]).

div_gnuplot_2

For this reason I would like to perform some stop and restart for the coupling simulation.
In other discourse, I read that CalculiX wrote restart file only at the end of the simulation. Moreover in my tests it write only if I put:

*RESTART,WRITE,FREQUENCY=1

If I use the same save frequency like the output results (that in my case in 200) even at the end of the simulation CalculiX doesn’t write nothing.

*NODE FILE, FREQUENCY=200
U
*EL FILE, FREQUENCY=200
S
*END STEP

Ok, now I’m trying with this strategies:

  1. start the coupling with a dt=1[ms] till t=0.18[s]. In this case the max Courant is below 0.7.
  2. restart the coupling with a dt=0.05[ms] till t=0.26[s] (ending phase of the water collision).

My question is:

how do I have to consider the max-time in the precice-config.xml?
At the beginning I thought it like a total time, but the coupling didn’t stop at 0.26[s] like I expected.
I beleive to understood that:

  1. OF consider the time like a total time
  2. while CalculiX and preCICE consider it like an additional time.

So I changed my config file in this way:

  1. OF: endTime 0.26;
  2. CalculiX: dt = 0.05e-3; tfin = 0.08
  3. preCICE: max-time value=“0.08”

Is it right?