This paper summarizes the VIV-related research with the focus on flexible riser and pipe models subject to various engineering conditions. First of all, a series of numerical simulations for the purpose of validating the efficiency of FSI solution approach (ANSYS MFX) has been performed. The comparison between the simulation and the experimental data shows that the present FSI solution method is capable of giving acceptable estimation to VIV problems. As a meaningful application to engineering problems, some tentative simulation cases which are difficult to carry out in experiment, such as a flexible pipe with internal flow and multi-assembled pipes, have been successfully carried out. The coupling mechanism between vortex shedding and the VIV has been well interpreted.
Flow around a fixed or oscillating cylinder has received much attention in the past few decades. Since the current and wave propagates with high degree of complexity, the flexible risers/pipes are readily subjected to shear or oscillatory flow in real ocean conditions. As it is well known, vortex-induced vibration plays a leading role in determining the life span of marine risers. Due to the developing deepwater oil exploitation and massive use of underwater cables, the need to enhance our knowledge about vortex-induced vibration (VIV) for elastic pipe has greatly risen. A better comprehension of the vortex dynamics causing vibration and fatigue to risers is necessary. The fact that numerical simulations of VIV have been failing to accurately duplicate experimental processes mostly attributes to the complexity of the physics involved in the real problem. It is worth noting that the separation excursion and the coupling mechanism between the vortex wake and the dynamics of the structure are the key factors. From the multi-physics point of view, fluid-structure interaction (FSI) occurs when fluid interacts with a solid structure, exerting pressure to the structure.
