Dynamic behaviour of a pipe system under unsteady flow and structure vibration

In this article the subject fluid structure interaction is approached using a real and a computational model. Different scenarios are tested in a laboratory facility, where analysis of transient phenomena are created. Since it’s a fluid-structure elastic phenomenon, it’s important to study the phenomenon unsteady flow induced that reflects a structural vibration, developed when the steady-state velocity of a fluid is suddenly altered. Thus, the most adequate approach to model water-hammer phenomena is the one based on CFD (Computational Fluid Dynamics), and the FEM (Finite Element Method) to study the structural characteristics involved in the analysis of under pressure hydraulic structures pipe system. Through these models, it’s possible to study the behaviour of the fluid and the structure, as a whole, i.e. enabling the response of the structure change by the flow modification and, consequently, the response of the fluid by structure vibration. In general, simulations based on CFD analyses are used to better understand the dynamic phenomena. As dealing with a joined problem, two domains are created, the fluid-flow and the structure. The analysis are developed in order to show the possible consequences in terms of displacements, when the system is submitted to different loads and type of supports. It is equally emphasized the importance of integrated analysis (fluid-structure interaction) and the purpose of supports in water pipe systems in the infrastructures design. KEY-WORDS: fluid-structure interaction; FEM; Water hammer; CFD.