Development of a partitioned finite volume-finite element fluid-structure interaction scheme for strongly-coupled problems

Abstract

This work details the development of a computational tool that can accurately model strongly-coupled fluid-structure interaction (FSI) problems, with a particular focus on thin-walled structures undergoing large, non-linear deformations. The first part of the work investigates improving the efficiency with which a stable and robust in-house code models thin structures undergoing dynamic fluid-induced bending deformations. Variations of the existing finite volume formulation as well as linear and higher-order finite element formulations are implemented. The governing equations for the solid domain are formulated in a total Lagrangian or undeformed conguration and large geometrically non-linear deformations are accounted for. As will be demonstrated, the finite volume approach exhibits similar disadvantages to the linear Q4 finite element formulation when undergoing bending. An enhanced finite volume approach is discussed and compared with finite element methods. The second part of this work is concerned with fluid-structure interaction (FSI) modelling. It considers the implementation and coupling of a higher-order finite element structural solver with an existing in-house fluid-flow solver. The coupling between the fluid and structural domains is rigorously assessed. The developed technology is validated through the simulation of representative two-dimensional strongly-coupled problems, on which rigorous mesh and temporal independence studies are also conducted. The results of three-dimensional FSI test-cases are also presented.