Methodology of Computational Fluid-Structure Interaction with Applications for Complex Nonlinear Problems.

Anvar Gilmanov, Research Associate, St. Anthony Falls Laboratory, University of Minnesota

Computational fluid dynamics methods have advanced in recent years to be able to carry out fluid structure interaction (FSI) simulations of nonlinear problems with large deformations and displacements of flexible structures in a fluid flow. The Immersed Boundary Method (CURVIB) and Rotation-Free Shell Finite Element (FE) solvers are coupled together on a flexible solid–fluid interface, providing an efficient methodology for solving wide class of FSI problems. Various computational methodologies are discussed in order to emphasize the advantages of CURVIB-FE-FSI.  The coupled CURVIB-FE-FSI method is validated by applying it to simulate two FSI problems involving thin flexible structures: vortex-induced vibrations of a cantilever mounted in the wake of a square cylinder at different mass ratios and at low Reynolds number; and the more challenging high Reynolds number problem involving the oscillation of an elastic inverted flag. Simulations of fluid-structure interaction of flexible heart valve with pulsatile blood flow were performed on two types of aortic valve: healthy, trileaflet aortic valve (TAV) and bicuspid aortic valve (BAV), which is a congenital heart disease. The computed results reveal major differences between the TAV and BAV flow patterns, which are discussed in this presentation.