Software Coupling for Computer Aided Analysis of Fluid-Structure Interaction - Artificial Heart Valve Application

This paper on "Software Coupling for Computer Aided Analysis of Fluid-Structure Interaction - Artificial Heart Valve Application" was presented at the NAFEMS World Congress on Effective Engineering Analysis - 25-28 April 1999, Newport, Rhode Island, USA.

Summary

The new developed open platform COCOLIB is presented for coupling of commercial flow (CFD) and structural (FEM) analysis codes. General aspects of computer aided fluid-structure interaction are discussed, some of the special features and the main advantages of the COCOLIB loose coupling approach are given. The proposed method is tested with a simple two-dimensional test case, an elastic flap in a flow channel, where also experimental results exist. Numerical results of the COCOLIB coupling are given for two different coupling applications: explicit FEM/ CFD (time-dependent) and implicit FEM I CFD (steady state). The agreement of the code coupling is very good also for matching and non-matching grid versions. The coupling algorithms are robust, convergence is given for all analyzed test cases.
A much more complex industrial application of fluid-structure interaction is he analysis of Sulzer artificial heart valves. In a first step a complete opening / closing cycle of a flexible 2D leaflet valve is carried out, considering large deflections and contact conditions between leaflets during the closing phase of the valve. The COCOLIB approach uses for this test case a nonlinear explicit FEM/ CFD coupling in time domain. Up to now the opening of a complete 3D flexible tricuspid artificial heart valve is also possible. Here the next step is the fully coupled computation.
The functionality of the individual codes are preserved (loads/boundary conditions, materials, element types, analysis procedures) and the specific experience of the structural and fluid dynamics engineers can be used in a joined solution procedure.