慢漂运动下多成分锚泊线阻尼参数研究

Parameter study on multi- component mooring line damping due to slow drift motion

锚泊线提供的阻尼力对平台耦合运动特别是慢漂运动响应有显著影响。以应用于工程的多成分锚泊线为研究对象,阐述了锚泊阻尼的定义与研究方法。借助海工软件Orca Flex进行时域非线性动力分析,选取上部平台慢漂运动的周期与振幅、流速大小与流速分布形式、锚泊线拖曳力系数、附加质量系数,研究锚泊阻尼与它们的关系,探讨锚泊线各成分贡献阻尼受水动力系数变化的影响。结果表明除附加质量系数外,其余参数对锚泊阻尼有较大影响,钢链成分锚泊线贡献阻尼对水动力系数改变较敏感。本文结论可为海洋浮式平台锚泊系统设计提供参考。

The damping force provided by mooring line plays an essential role in determining the coupled motion response,especially the low-frequency slow drift motion,of the platform. Based on a multicomponent mooring line which is applied in a practical engineering project,the definition and the research method of the mooing line damping is described. Period and amplitude of the vessel slow drift motion,current speed,current type,drag coefficient and added mass coefficient of the mooring line are selected for the parameter study. The contributions to damping varying with hydrodynamic coefficient by respective components of the mooring line are compared. The research is realized by means of time-domain non-linear dynamic analysis in Orca Flex Software. As a result,apart from added mass coefficient,all the parameters has prominent effects on the mooring line damping,and the contribution of chain component to mooring line damping is more sensitive to the hydrodynamic coefficient variation. The conclusions provide references for the mooring system design of floating vessels.