Simulation der Fluid-Struktur-Interaktion in arteriellen Bypässen

A partitioned solution approach for fluid-structure interaction problems in the arterial system

“…The method is based on the ideas in [215] and was first used in the context of partitioned FSI simulations in [51]. Since then, it has been refined, investigated and applied by the same author (see [53,56,55]) as well as other research groups (see e.g [87,122,163,162,164]).…”

“…Isolated from the question about the most suitable method for the three-dimensional FSI problem, the partitioned solution approach can be used to flexibly couple the FSI problem with reduced order models that account for the surrounding. The practicability of such a coupling was shown in [164]. In the present work, the idea of treating the individual models (fluid, structure, surrounding tissue, distal vessel network) as black-boxes is investigated extensively.…”

“…In the studies 3.3 Mechanical models for the cardiovascular system mentioned above, this is realized by including numerical damping into the problem (mass proportional in [188], through the temporal discretization scheme in [203,206]). A more powerful approach is to use an elastic or viscoelastic foundation as done in [164,146]. Of course, shifting the boundary of the structural mechanics problem further away from the outside of the adventitia would be the most accurate way of describing the behavior of the surrounding tissue.…”

“…Here, only a soft-tissue material model is used and the focus is put on the partitioned coupling of the additional subproblems representing the reduced models, namely the elastic foundation and the windkessel model and its influence on the performance. In so far, the investigation follow the proposal in [164], where the same multifield problem was used to simulate the flow in an endto-side anastomosis and the need for and investigation of the performance was emphasized. Additionally, the possibility to use adaptive time step sizes is considered here.…”

“…Figure 5.47 schematically shows the resulting interaction between all subproblems in this fully coupled case. Here, the investigations are restricted to the subproblem highlighted in blue, which yields the same simulation and modeling approach as the one followed in [164].…”