[Jim1310]

Hello foamers,

I am trying to simulate the motion of a 2D floating object in a wave flume using relaxation zones (with the aid of the waves2Foam library). I am considering two cases. In the first case i am restricting the motion of the object in the horizontal direction (so only rotation and vertical motion). In an extension of this case, i would like to let the horizontal motion free as well. In this situation there would be some drifting motion of the object as well.

The simulation strategies and problems i am able to think of/implement (partially) are the following. One option would be to rotate the entire mesh to avoid excessive deformations, but i don't know how valid this option would be especially in case where there is also drift motion (this is something i have done). Another option is to deform the mesh in an area around the object, but in case of extreme roll angle the mesh quality will degrade so much that the simulation will crush. I guess AMR could be one remedy for excessive deformations, but i don't know if it can be combined with mesh motion. Another solution to avoid mesh morphing would be to use overset meshes. I am having some problems with it though because i recently tried to modify the "floatingBodyWithSpring" case in "tutorials/multiphase/overInterDyMFoam/" (v2106) i cant figure out the problem. In the log.overInterDyMFoam it looks like the simulation starts, but the solution diverges almost immediately. After some iterations there are these warnings:

--> FOAM Warning : 
    From Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&, bool) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 85
    No base point for face 632, 4(657 698 780 739), produces a valid tet decomposition.
--> FOAM Warning : 
    From Foam::triFace Foam::tetIndices::faceTriIs(const Foam::polyMesh&, bool) const
    in file meshes/polyMesh/polyMeshTetDecomposition/tetIndicesI.H at line 85
    No base point for face 632, 4(657 698 780 739), produces a valid tet decomposition.
--> FOAM Warning :

Any advice? Thank you in advance.

[Jim1310]

I actually found a case in the forum, where there was an almost working 2d simulation of a floating box and the pitfall was found, check it out here:



2D floating object in overInterDyMFoam...