  We consider a loosely coupled algorithm for fluid-structure interaction based
on a Robin interface condition for the fluid problem (explicit Robin-Neumann
scheme). We study the dependence of the stability of this method on the
interface parameter in the Robin condition. In particular, for a model problem
we find sufficient conditions for instability and stability of the method. In
the latter case, we found a stability condition relating the time
discretization parameter, the interface parameter, and the added mass effect.
Numerical experiments confirm the theoretical findings and highlight optimal
choices of the interface parameter that guarantee an accurate solution with
respect to an implicit one.
