Title: On a Fixed-Grid Approach for 3D FSI-Simulations Including Large Structural Deformations

Speaker: Axel Gerstenberger, Technical University of Munich, Germany

Date/Time: September 9, 2009 at 9:00 – 10:00am          

Location: CSRI Building, Room 90 (Sandia NM)

Brief Abstract: This talk illustrates an ongoing effort to develop a 3-d fixed-grid Fluid-Structure Interaction (FSI) scheme that can be applied to the interaction of most general structures with incompressible flows. As opposed to moving mesh techniques based on the Arbitrary-Lagrangean-Eulerian (ALE) formulation, the eXtended Finite Element Method (XFEM) in combination with stabilized, equal order (Q2Q2) elements is used to account for the moving, implicit interface on the fixed Eulerian uid grid. The commonly used Lagrangean structural formulation is not affected by the enriched fluid formulation, hence, no restrictions exist with respect to possible structure deformation modes or the choice of structural material models. Along the fluid-structure interface, a novel Lagrange multiplier technique was developed to ensure a consistent coupling between kinematic and kinetic variables of both fields. The technique is based on an element-wise velocity-pressure-stress ansatz and allows for a element-wise condensation Lagrange multiplier unknowns. The resulting linearized system allows the application of parallel algebraic multigrid solution techniques. The talk sketches the general FSI formulation and its implementation into an existing monolithic and partitioned FSI coupling framework. The presentation closes with fluid and FSI benchmark simulations that shall verify the correctness of the developed approach.

CSRI POC: Ray Tuminaro, 925-294-2564