A methodology and computational system for the simulation of fluid-structure interaction problem

A. R. E. Antunes, P. R. M. Lyra, R. B. Willmersdorf
2005 Journal of the Brazilian Society of Mechanical Sciences and Engineering  
In this paper a flexible finite element computational tool developed to investigate fluidstructure interaction applications in two dimensions is described. We consider problems which can be modelled as a viscous incompressible fluid flow and a rigid body-spring system interacting nonlinearly with each other. The coupling is dealt with the use of an interface approach, in which each physics involved is solved with different schemes and the required information is transferred through the
more » ... hrough the interface of both systems. This approach is, at least in principle, very flexible and computationally efficient as the best available scheme can be adopted to solve each physics. Here, a stabilized FEM considering the "ALE" (Arbitrary Lagrangian-Eulerian) formulation with Crank-Nicholson timeintegration is employed for the fluid-dynamics analysis, and the Newmark Method is used for the structural dynamics. Several important tools were incorporated into our system including different possibilities for the mesh movement algorithm, the computational domain decomposition into regions with and without mesh deformation, and the remeshing strategy (either global or local) to keep the necessary mesh quality. As application we present a study of the forced lock-in phenomena and a preliminary investigation on the suppression (or at least the reduction) of the vortex induced vibrations (VIV) on a solid circular cylinder using an idealization of a periodic acoustic excitation. Keywords: Fluid-structure interaction, vortex induced vibrations (VIV), finite element method (FEM), arbitrary Lagrangian-Eulerian (ALE) formulation, lock-in phenomena, suppression of structural vibration Numerical Formulation Most fluid structure interaction problems where there is a strong coupling between the displacement of the structure and the flow field are characterized by large displacements of some of the boundaries of the domain. The regions close to these moving boundaries are more naturally discretized with a Lagrangean approach. The fluid regions away from the moving boundaries, however, are more naturally treated with a conventional Eulerian formulation, with a fixed reference frame. We use an Arbitrary La-
doi:10.1590/s1678-58782005000300007 fatcat:tquixycpcrc73crsk7eg7gfrp4