Robin-Neumann semi explicit and explicit schemes in fluid-structure interaction problems
Résumé
We are interested in the simulation of blood flows in large arteries. In the frame of domain decomposition standard explicit coupling schemes can be viewed as one iteration in a Dirichlet-Neumann algorithm with a convenient first guess. For this class of problems, such coupling schemes are unstable due to the added mass effect. Implicit coupling schemes based on a Dirichlet-Neumann algorithm avoid these instabilities but are computationaly time consuming. Robin-Neumann schemes, recently introduced, guarantee stability and optimal first-order accuracy for a linear Stokes/thin-solid coupled system. In this explicit coupling schemes, the displacement is extrapolated in the fluid sub-step and then it is corrected in the solid. These algorithms will be presented in a fully non-linear framework for the coupling of the Navier-Stokes equations (in ALE form) with a non-linear shell structure or a three dimensional structure. Comparisons in terms of accuracy and efficiency with more standard schemes such as non-incremental explicit schemes and implicit schemes will be discussed.