Efficient fsi codes coupling with possible large added mass effects: applications to rigid and elongated flexible bodies in the maritime field

Co-simulation, which involves codes coupling, is the most popular technique in an industrial context to deal with multi-physics applications. This is mainly due to its modular nature and the use of specialized solvers which have the ability to integrate the most advanced numerical techniques and physical models in each scientific field. However, in many configurations, the development of coupling algorithms, easy to implement, leading to a stable, accurate and efficient tool is generally not straightforward. For Fluid- Structure Interaction (FSI) configuration involving hydrodynamics, it is well-known that added-mass effect tends to distabilize classical coupling algorithms, such as the Block- Gauss-Seidel algorithm (often denoted by Dirichlet-Neumann decomposition too). Here, some modifications of this algorithm are proposed to reach a weak-intrusive stable coupling method for rigid and elongated beam-like bodies. Efficiency is discussed and some applications are shown to demonstrate the capabilities of such a coupling