Quasi-Newton and artificial compressibility based partitioned algorithms for strongly coupled fluid structure interactions

In this thesis, fluid-structure interactions (FSI), a multi-physics application, was investigated in detail. The reasons why FSI applications were developed, what those applications are, and different approaches that had been used on those FSI problems were explained and discussed. The two coupling approaches in FSI, which are monolithic coupling and partitioned coupling, were explained briefly. Then, so called "black-box" partitioned FSI coupling schemes were investigated. Two algorithms based on black-box partitioned FSI coupling scheme, Aitken's dynamic relaxation and the state of the art IQN-LS methods were explained in detail and their performances were compared by a FSI benchmark case. The superior performance of IQN-LS method over Aitken's dynamic relaxation was confirmed. Nevertheless, one of the major problem of partitioned coupling methods, which was described as the "incompressibility dilemma" for fully-enclosed, incompressible problems, was explored and a potential solution to it were discussed. Lastly, FSI in hemodynamics and blood flow simulations were introduced. The reasons why FSI techniques are required in order to simulate the blood flow through artery simulations in hemodynamics were explained briefly. Finally, IQN-LS, based solver was used in order to simulate 3D blood flow through large artery. The simulation was composed of incompressible, Newtonian, laminar flow solver with pulsatile velocity profile and linear elastic structural solver. All setup parameters and the results of the simulation were discussed in detail. The suitability of IQN-LS algorithm for further hemodynamics FSI applications were discussed.