软刚臂单点系泊系统系泊力计算两种方法对比

Comparison of the Two Calculation Methods of Mooring Force for the Single Point Mooring System of Soft Yoke

为比较软刚臂单点系泊系统系泊力计算中的两种不同方法,运用ANSYS-AQWA软件,基于三维势流理论基础,应用源汇分布法,分别采用频域和时域方法,计算某FPSO的运动响应和系泊力,讨论了两种方法的优缺点。频域方法基于准静态,按照CCS规范进行,方法简单,误差较大,适用于初步方案设计阶段;时域动态方法基于多体动力学,充分考虑系泊系统的结构形式及其动力项对FPSO运动性能的影响,对FPSO及系泊系统进行耦合分析,能更好的预报系统的运动响应和系泊力,适宜在详细设计阶段使用。

In order to compare the two different methods of mooring force calculation for the single point mooring system of soft yoke,based on three-dimensional potential flow theory and source-sink distribution method,the motion response and mooring force of one FPSO was calculated in ANSYS-AQWA,by using frequency domain and time domain methods respectively. It was shown that the frequency domain method,which is based on quasi-static method,is suitable for the stage of preliminary design because of simple method but inaccurate. The method of time domain,which is based on multi-body dynamic analysis,can fully consider the specific format of mooring system and the influence of dynamic term on motion performance of the FPSO to analyze the FPSO and soft yoke coupling system. It can give a better prediction of the motion response and mooring force of the system.Therefore,it is suitable for the stage of detailed design.