海底电缆涡激振动流固耦合有限元建模分析

Fluid-Structure Coupled Finite Element Modeling Analysis of Vortex Induced Vibration Characteristics of Submarine Cable

海底电缆在洋流冲刷下产生涡激振动会导致缆体疲劳引发故障,严重影响电网系统的安全和稳定,研究缆体涡激振动特性对故障预警十分必要。采用模型相似理论首次建立了110kV光纤复合海底电缆涡激振动的有限元模型,通过有限元法得到模型的共振频率,并通过流固耦合方法对不同流速下缆体涡激振动进行计算和数据分析,获得了不同流速下的升阻力系数、涡激振动幅度、频率和振型。结果表明,模型计算出的涡激共振频率与理论值一致,获得的缆体振动数据详实、准确。研究克服了海底电缆涡激振动实体试验开展困难的难题,为海底电缆涡激振动特性研究和疲劳分析提供了可行方法和数据支持。

Vortic-Induced Vibration(VIV) of submarine cables caused by ocean current scour will lead to cable fatigue and failure,which will seriously affect the safety and stability of power system.Therefore,it is necessary to study the characteristics of VIV of submarine cables for fault warning.In this paper,the finite element model of vortex-induced vibration of 110 kV fiber composite submarine cable was firstly established by using model similarity theory.The resonant frequency of the model was obtained by finite element method,and the vortex-induced vibration of the cable body at different flow rates was calculated and analyzed by fluid-structure coupling method,and the lifting drag coefficient,amplitude,frequency and mode of vortex-induced vibration at different flow rates were obtained.The results show that the vortex-induced resonance frequency calculated by the model is consistent with the theoretical value,and the cable body vibration data obtained are detailed and accurate.This study overcomes the difficulty of submarine cable VIV physical test and provides feasible methods and data support for submarine cable VIV characteristics research and fatigue analysis.