软刚臂单点系泊装置对小型浮式平台性能影响研究

Research on the influence of soft yoke single point mooring device on the performance of one small floating platform

软刚臂单点系泊是浅水海域FPSO重要的系泊方式之一,其结构尺寸及重量较大。通常FPSO排水量较大,软刚臂单点系泊装置对其影响可忽略不计。当软刚臂单点系泊装置用于排水量较小的浮式平台时,其对浮式平台的影响不可忽略。为研究单点系泊装置对小型浮式平台性能的影响,运用AQWA软件,基于耐波性理论基础,分别计算浮式平台在单点系泊状态和顺应式系泊状态下的频响及固有周期;采用时域分析方法,分别计算浮式平台在2种系泊状态下的运动响应。计算结果表明,单点系泊装置会减小浮式平台横摇频响峰值,增大其对应的周期,对纵摇和垂荡的频响影响不大;明显增大横摇和纵摇的固有周期,略微减小垂荡的周期,增大3个运动量的阻尼;增大横摇和垂荡的平均值以及垂荡的幅值,2种系泊方式对横摇和纵摇幅值的影响与风浪流方向分布有关。

Soft yoke single point mooring System is one of the most important mooring methods of FPSO in shallow waters,Which structure size and weight are large.Usually,The influence of soft yoke single point mooring device on FPSO can be ignored because of the large displacement.It may have obvious effect on the performance when the soft yoke single point mooring device is used on the floating platform with small displacement.This paper is to study on the influence of single point mooring device on the performance of small floating platform.Using AQWA software and based on the sea keeping theory,this paper calculate the frequency response and natural period of the floating platform under the single point mooring condition and free state respectively.The time domain analysis method is adopted to calculate the motion response of the floating platform in two moored conditions.The results show that the single point mooring device can decrease the peak of Roll frequency response and increase the corresponding period of the floating platform and has little impact on the pitch and the heave frequency response.The natural period of Roll and Pitch is obviously increased,and the period of Heave is reduced slightly.In addition the damping of the three movements are all increased.The average values of roll and heave are all increased,including the amplitude of heave.The two types of mooring on the influence of Rool and Pitch amplitude are related to the distribution of the wind,wave and current.