A FULLY COUPLED FLUID-STRUCTURE INTERACTION ALGORITHM

Fluid-structure interactions, that is interactions of some movable or deformable structure with an internal or surrounding fluid flow, are of great importance due to their many engineering and biomedical applications. Accurate prediction of fluid-structure interactions is crucial for many engineering structures in order to avoid potential aeroelastic/hydroelastic instability issues. Failing to consider these effects can be catastrophic, especially in structures comprising materials susceptible to fatigue. A new numerical algorithm based on the ALE formulation has been developed for a fully coupled solution of the large-scale FSI problems where the fluid is modelled by the incompressible Navier-Stokes equations and the structure is modeled by the St. Venant-Kirchhoff model. The governing equations of the fluid domain are discretized using an Arbitrary Lagrangian-Eulerian (ALE) formulation based on the side-centered unstructured finite volume method where the velocity vector components are defined at the mid-point of each cell face while the pressure is defined at the element centroid. The deformation of the solid domain is governed by the constitutive laws for the nonlinear Saint Venant-Kirchhoff material and the classical Galerkin finite element is used to discretise the governing equations in a Lagrangian frame. Newmark type generalized-alpha method is employed to integrate in time the solid dynamic equilibrium equation.

The computed vortex structure (Q-criteria) for a flat plate behind a rectangular cylinder at Re=648 (A. Eken).

The fluid-structure interaction witin a celabral artery with aneurysm (A. Eken).

The deformation of red blood cells (RBCs) in a narrow channel (A. Cetin).

The three-dimensional buckling of red blood cells (RBCs) in a narrow channel. Bending stiffness is significantly reduced (A. Cetin).

The three-link swimmer proposed by Eldredge, 2008 (E. Dilek).