Fluid-Structure Interaction Analysis For Vortex-Induced Vibration Of Reinforced Thermoplastic Pipe

When the marine riser is working, it will bear the effect of inner flow and the outside load. One of the results of these loads is Vortex-Induced Vibration (VIV). VIV is recognized by the American and Norwegian standards as the main reason of fatigue failure of risers, and has already caused extensive concern of the domestic and foreign scholars and offshore oil engineering industry.Based on Computational Fluid Dynamics (CFD) and Computational Solid Dynamics (CSD), several simulations concerning VIV problems are conducted. Meshes with varies densities are applied in flow around cylinder simulations, in order to determine an appropriate mesh. Simulations are carried out with different Reynolds numbers and results are compared to former studies. Flow around pipes with two different tails are studied, to see how the lift force, drag force and vortex shedding frequency are affected. The modal of the whole scale pipe is studied with and without inner fluid. Simulations are carried out on the ANSYS Workbench platform concerning VIV of an RTP with aspect ratio 30 and diameter 0.365m in a flow of which the Reynolds number is 4 ×105. RNG k-ε、, SST κ-ω and SST-SAS turbulence models are applied and the results are compared to see which model leads to a good solution. SST-SAS is chosen for further study. It is shown that the deformation of RTP increases significantly when the structure characteristic frequency gets close to vortex shedding frequency.