[RicardoLB]

Hello everyone!
I am starting to work with overset meshes and taken the floatingObject tutorial as a starting point. I want to get a 2D floating object setup to carry out simple heave decay tests (and eventually to add wave generation and absorption boundary conditions). I have a half-working setup ready.



I am getting this error repeatedly:

--> FOAM FATAL ERROR:
Cell:2115 at0.42125 0 0.254285714286) zone:0 changed from hole to calculated but there is no donor

This happens in a cell which is in the last and second to last timesteps a hole... I attach an image. Can anybody give me hints on how to solve this problem?



I also observe some apparently strange movements of the floating object as if it where excited (I don't explain myself the initial acceleration from the initial position of non-equilibrium between the waterline and the submerged volume and the following steps). I think I have assigned the correct mesh groups and boundary conditions; are they correct?


I attach the case folder.


Greetings,
Ricardo

[romainping]

Hi Ricardo,

I am facing the same error message on OF 1812. I do not have this error on version 1712...
Have you found a solution ?
Thanks for your help,

Romain

[Jim1310]

This is a case that particularly interests me, so i searched what the pitfall had been. Eventually it must be the fact that although there should be motion only in the plane, for some reason (probably due to arithmetic error) there is some parasitic movement-rotation outside of the plane. It can be seen in the log-file of the solver that initially there is an off-plane rotation of about ~10^(-30), which is gradually build up until ~10^(-6) where the simulation cruses. This can be easily solved by imposing movement constraints (see wiki-page: https://openfoamwiki.net/index.php/P...on_and_Damping). I imposed a plane constraint (movement only on the z-x plane) and an axis constraint (rotation only in y-axis) and it worked without a problem (my Of version: v2106).