the problem on density ratio in icoFsiFoam with weakly coupling
 

Dear, all

I'm trying to test a case of a cantileiver column using the tutorial of the icoFsiFoam solver in openfoam 1.5x.

icoFsiFoam is known as the solver of Fluid-Strucutre Interactions with weakly coulping.

I would like to know why FSI solver with weakly couping leads to a serious divergence problem when densities between strucuture and fluid are similar or, in other words, desitiy ratio (strucuture/fluid) is high.

If you know some hints and thesises on it, your comments are greatly appreciated.

Regards!