A MODIFIED CBS FINITIE ELEMENT APPROACH FOR FLUID-STRUCTURE INTERACTION

This paper performed a finite element analysis of fluid-structure interaction (FSI) problems under the arbitrary Lagrangian-Eulerian (ALE) description. The loosely-coupled partitioned algorithm was employed where Navier-Stokes equations were solved by the semi-implicit characteristic based split (CBS) scheme while the equation of motion for structure was solved by the Newmark-β technique. A mass source term, in accordance with the so-called geometric conservation law (GCL) when computing on moving meshes, was adopted in the pressure Poisson equation, the efficient moving submesh approach (MSA) was used for the mesh deformation in the computation of fluid-structure interaction, and a smoothing algorithm was introduced to avoid the degradation of moving meshes if a long-playing simulation was carried out. Such a technique as modified combined interface boundary condition (MCIBC) method was applied on the velocity and momentum fluxes along the interface. Consequently, the present loosely-coupled partitioned procedure achieved better accuracy and stability on the study of fluid-structure interaction. Moreover, the proposed method was applied to the flow-induced vibration analysis of one single circular cylinder and two circular cylinders. The numerical results showed high efficiency and a good agreement with the existing experimental and numerical data.