A comparative study between partitioned and monolithic methods for the problems with 3D fluid-structure interaction of blood vessels

The problem with Fluid structure interaction (FSI) can be simulated by monolithic (fluid and structured equations are solved in a single monolithic matrix) or partitioned approach (fluid and solid equations are sequentially solved, and coupling is achieved subsequently through iteration). This paper presents a comparative study between monolithic (in-house) and partitioned (ANSYS) methods for 3D FSI problems. Pressure wave propagation in a flexible tube and a pulsatile flow interacting with a mild stenotic vessel are used in this study. The present numerical experiment reveals that the monolithic approach produced better convergence behavior and consumed lower CPU time than the partitioned method for the selected 3D FSI problems. Furthermore, the partitioned method had a severe convergence problem during strong interaction of fluid and structure.