An interface quasi-Newton algorithm for partitioned simulation of fluid-structure interaction

To solve a fluid-structure interaction problem efficiently in a partitioned way with a “black-box” flow solver and structure solver, an interface quasi-Newton technique with an approximation for the inverse of the Jacobian from a least-squares model (IQN-ILS) has been developed. In this work, the implementation of the IQN-ILS algorithm without explicit creation of the approximation for the inverse of the Jacobian is explained and it is demonstrated that the IQN-ILS technique can be implemented easily in simulation environments which currently use relaxation methods. Simulations of a flexible beam behind a cylinder and the propagation of a pressure wave in a carotid artery indicate that the IQN-ILS algorithm outperforms Aitken relaxation and that it has similarp erformance as the interface block quasi-Newton algorithm with approximate Jacobians from least-squares reduced-order models