尾流干涉下跨接管碰撞概率研究

Research on Collision Probability of Flexible Jumper under Interference of Wake

基于“不允许碰撞”的设计思路,建立了跨接管单元对的碰撞极限状态方程,并结合Blevins尾流干涉模型建立了整体耦合模型。分别采用Gumbel极大值分布和三参数Weibull分布对间距极值序列进行拟合,考虑跨接管外径的随机性,通过最小二乘法和灰色模型-极大似然法以及一次可靠度方法对不同工况下的碰撞概率进行了验证分析。结果表明,两种分布类型和参数估计方法均能对间距极值序列有较好的拟合效果;流速和初始阻力系数的减小、上端初始间距的增大都会导致跨接管碰撞概率的减小。论文所提出的分析流程和方法可为尾流干涉下海洋立管的碰撞概率分析提供参考。

Based on the design criterion of non-collision,evaluation method of spacing between flexible jumper elements and collision limit state equation is constructed and an overall coupling model is established with a combination of Blevins wake interference model.Then,Gumbel maximum value and three-parameter Weibull distribution are used to fit the sequence of extreme spacing.Considering the randomness of the outer diameter caused by marine attachments and corrosion,the least square method and the gray model-maximum likelihood method are used to verify and the probability index of collision and probability of failure under different working conditions with the first order reliability method.The results show that two distribution types and parameter estimation methods have a good fitting on the sequence of extreme spacing.Decrease of the flow velocity and the initial resistance coefficient,or increase of the initial spacing between the upper ends will cause decreasing the probability of collision between jumpers.Analysis and proposed method may provide a reference for analyzing collision of ocean risers under wake interference.