The Research On Dynamic Response And Laying Efficiency Of Umbilical Cable Device Based On VIV Principle

With abundant oil and gas resources in the deep sea,umbilical cable is an essential equipment for deep sea oil exploitation.During the laying of the umbilical cable,the mechanical properties of the umbilical cable will change due to the laying parameters and currents.If the vortex-induced vibration of the umbilical cable during the laying process will affect the laying efficiency.Therefore,studying the vortex-induced vibration during the laying of the umbilical cable can ensure the laying efficiency under the premise of safety.Firstly,the theory of umbilical cable static theory is summarized,and the umbilical cable model based on large deformation theory is established.The numerical solution of the model is obtained by MATLAB programming.The results are compared with Orca Flex,and the umbilical cable is studied with the model and Orca Flex,initial horizontal distance,installation vessel offset,relative flow rate and direction on the umbilical cable laying.Then,using ANSYS software,the vortex-induced vibration of the umbilical cable with large slenderness ratio under uniform flow was simulated by slice method.The influence of water flow and tension on the vibration of catenary umbilical cable was studied.Finally,the variation of the vortex-induced vibration experimental system of the pipeline is built to study the effect of tension variation on the vortex-induced vibration frequency and amplitude of the umbilical cable.Static analysis reveals that the wet weight and stiffness of the umbilical cable,the initial horizontal distance and the offset of the installation vessel,the relative flow rate and direction of the installation vessel and current,have an impact on the morphological and mechanical properties of the umbilical.The finite element simulation shows that the umbilical cable will be locked in frequency within a certain range of relative flow rate,and the amplitude ratio will increase greatly.The increase of tension can reduce the vortex-induced vibration amplitude and increase the vibration frequency,but the frequency and amplitude of tension change have little effect on vortex induced vibration.The experiment also verified the simulation results.