Numerical investigation of homogeneous equilibrium model and fluid-structure interaction for multiphase water flows in pipes

- We model in three dimension structure-structure contact, fluid-structure interaction and cavitation in a single-elbow pipe system.
- We show that considering fluid-structure interaction strong coupling is mandatory to obtain reliable results.
- We present validation against experimental data.

To simulate fast transient phenomena, one must consult realistic compressible fluid models that take into consideration phase change, shock wave generation and its propagation. In an industrial framework, such phenomena occur mostly near industrial apparatuses such as pumps, propellers, impellers and control valves. The rapid collapse of cavitation produces strong shock waves that may harm the interacting structure. In this paper, we present a numerical methodology to solve three-dimensional complex industrial problems through the combination of Homogeneous Equilibrium Model (HEM) phase change model proposed by Saurel et al. (1999), Arbitrary-Lagrangian-Eulerian (ALE) formulation and Fluid Structure Interaction (FSI). The HEM model is implemented in the LS-DYNA® software where the ALE and FSI capabilities were co-developed by the third co-author. To validate the proposed numerical methodology in order to extend the past one-dimensional solution, we consider the study of Tijsseling et al.(1996) on fluid structure interaction and cavitation in a single elbow pipe system that provides both numerical and experimental results.