Numerical Simulation Of Vortex‐Induced Vibration For Top Tension Risers By Coupled Fluid‐Structural

Deep-sea risers are important parts of deep-sea engineering equipment. Under the complex marine environment conditions, the vortex-induced vibration will occur, and this will induce risers’fatigue damage. At present, VIV and fatigue researches of deep-sea risers are forefront subject in marine fields.With the CFD method, viscous flow around circular, the simulations of Forced Oscillating Cylinder at high amplitude ratio and one-way and two-way fluid-structure interaction VIV are presented, and top tension risers’vortex-induced vibrations is simulated. Navier‐Stokes?equation?is?solved?by?software?FLUENT, the 2D and 3D of Viscous Flow around circular are simulated; With the dynamic mesh of Fluent, the simulation s of Forced Oscillating Cylinder at high amplitude ratio is presented. Combining the fluid equation and the risers’movement equation, one-way and two-way fluid-structure interaction VIV are simulated. Finally, using the theory of slice, deep-sea risers’3D vortex-induced vibrations are simplified,through the CFD software and FEA software ABAQUS, deep-sea risers’3D FSI VIV is simulated.Through this paper, the lift coefficient and vortex shedding frequency are obtained .Comparing between the results based on the 2D analysis and the 3D analysis,the 3D results are smaller than the 2D results. With the dynamic mesh of Fluent, the simulation s of Forced Oscillating Cylinder at high amplitude ratio is presented. The variation of lift coefficient and vortex shedding frequency are obtained, the“lock-in”region is given. The results of one-way and two-way VIV simulation show that larger damp will weaken the VIV level, and in the low quality, small damping, longitudinal freedom vortex-induced vibration will aggravate transverse vibration. The results show that using the slice theory to study the VIV of TTRs is feasible.