水深对水上软刚臂单点系泊系统影响研究

Research on the influence of water depth on soft yoke single point system

在渤海海域服役的大型FPSO作业水深较浅,水深的变化会直接影响FPSO运动性能。为研究水深对FPSO附加质量、阻尼系数、运动幅度以及波浪力等水动力参数的影响,应用AQWA软件,基于三维势流理论,求解FPSO各项水动力参数;利用多体动力学方法,建立FPSO和软刚臂系统的耦合时域运动方程,求解FPSO的六自由度运动及系泊载荷。计算结果表明,附加质量在低频范围内对水深更为敏感;随着水深的减小,6个自由度上的阻尼呈均增大,且在低频时变化比较明显;纵荡响应幅值在低频时远大于高频;随着水深的减小,纵荡运动极值和系泊力均显著增大,各运动平均值有所增大。

Large FPSOs operating in Bohai have relatively shallow water depths,and changes in water depth affect performance of the FPSO.In order to study the effect of water depth on the hydrodynamic parameters of FPSO such as added mass,damping coefficient,RAO and wave fore,AQWA software was used to solve the hydrodynamic parameters of FPSO based on the three-dimensional potential flow theory.The multi-body dynamics method was used to establish coupling model of the FPSO and soft yoke system to solve six degrees of freedom motion and mooring load of the FPSO.The calculated results show that the added mass is more sensitive to the water depth in the range of low frequency.As the water depth decreases,the damping of the six degrees of freedom increases and becomes obvious at low frequency.The surge RAO in low frequency is much larger than in high frequency;with the decrease of water depth,the extreme value and mooring force of the surge movement increase significantly,and the average value of each movement is also increase.