Multi-level acceleration with manifold mapping of strongly coupled partitioned fluid–structure interaction

Abstract

To accelerate the convergence of strongly coupled partitioned fluid–structure interaction simulations, the manifold mapping algorithm is used which combines a high-fidelity model with a low-fidelity model. A computationally inexpensive low-fidelity fluid–structure interaction (FSI) model is combined with a high-fidelity FSI model in order to accelerate the convergence of the coupling iterations of the high-fidelity FSI model. The manifold mapping algorithm is applied to the fluid–structure interaction problem in order to minimize the fluid–structure interface residual. Originating from multi-fidelity optimization, the manifold mapping algorithm is applied for the first time in a simulation context, instead of an optimization context. The manifold mapping algorithm is applied to an unsteady flow in a one-dimensional tube, incompressible laminar flow over a fixed cylinder with an attached flexible flap, and a wave propagation in a three-dimensional elastic tube problem. A reduction of approximately 50% in terms of high-fidelity iterations is achieved compared to the state-of-the-art Interface Quasi-Newton Inverse Least Squares algorithm. The convergence of the high-fidelity model is accelerated even further when information from previous time steps is reused.