While revising the sequential-staggered algorithm used in the paper by Förster et al. (also used in several other papers), I suddenly realised that the velocity BC at the interface is NOT enforced in this particular scheme.

From the pseudocode, we can see that the interface fluid velocity calculated in step b is not the same as the solid velocity calculated in step f.

Link to paper: Article Artificial added mass instabilities in sequential staggered ...

I would like to know what others think of this. I very much appreciate any insights and your experience in using this scheme.