Fluid-structure interaction (FSI) case study of a cantilever using OpenFOAM and DEAL.II with application to VIV

Abstract: This Master Thesis in Technical Mathematics at LTH, directed towards simulation and computation,has treated the subject of fluid-structure interaction (FSI) for incompressible flowwith small vibrations. The open source packages DEAL.II and OpenFOAM have been used to create a coupling between a finite element formulation for structure and a finite volume formulation for fluid ( gas or liquid ). A staggered solution algorithm for FSI has been implemented in C++ using Aitkens relaxation method together with a Reduced-Order-Model (ROM). The solution algorithm has been validated by using an application consisting of a cantilever immersed in a steady flow transversal to its axial direction. Also, vortex-induced vibrations (VIV) were calculated as a function of the flow velocity and successfully compared to empirical data. The study has demonstrated the usefulness of artifical damping to solve boundary condition problems in incompressible flow. The method presented is general and has a strong potential in technical applications where the structure is subjected to a surrounding fluid.