FSI ANALYSIS WITH CONTINUOUS FLUID FLOW USING FEM AND SPH METHODS IN LS-DYNA

Abstract

The purpose of this research was to investigate the prospect of continuous flow modelling in LSDYNA using SPH-FEM coupling. The both methods (SPH and FEM) are based on the continuum mechanics, however, SPH implementation uses Lagrangian material framework, while FEM uses an Eulerian formulation for the fluid analysis, and Lagrangian formulation for the solid analysis. The Lagrangian framework of the SPH means that we need to generate particles at one end, and to destroy them on the other, in order to generate a continuous fluid flow. The simplest way to do this is by using activation and deactivation planes, which is a solution implemented in the commercial LS-DYNA solver. Modelling of continuous fluid flow is practical in mechanical (naval) engineering for hydrofoil analysis and in bioengineering for blood vessel simulations. Results show that velocity fields obtained by SPH-FEM coupling are similar to velocity fields obtained by FEM. FEM only solution has a clear advantage in regards to execution time, however, SPH-FEM coupling offers greater insight into fluid structure interaction, that justifies the extra computational cost.