Freak wave is the common wave which has significant wave height and irregular wave shape, and it is easy to damage offshore structure extremely. The FPSOs(Floating Production Storage and Offloading) suffer from the ...Freak wave is the common wave which has significant wave height and irregular wave shape, and it is easy to damage offshore structure extremely. The FPSOs(Floating Production Storage and Offloading) suffer from the environment loads, including the freak wave. The freak waves were generated based on the improved phase modulation model, and the coupling model of FPSO-SPM(Single Point Mooring) was established by considering internal-turret FPSO and its mooring system. The dynamic response characteristics of both FPSO and SPM affected by the freak wave were analyzed in the time domain. According to the results, the freak waves generated by original phase modulation model mainly affect the 2nd-order wave loads. However, the freak waves which are generated by random frequencies phase modulation model affect both 1st-order and 2nd-order wave loads on FPSO. What is more, compared with the irregular waves, the dynamic responses of mooring system are larger in the freak waves, but its amplitude lags behind the peak of the freak wave.展开更多
In this study, we perform a series of numerical calculations on two vessels in the time domain. One vessel maintains its position using an internal turret and catenary mooring lines, while the other is moored to the f...In this study, we perform a series of numerical calculations on two vessels in the time domain. One vessel maintains its position using an internal turret and catenary mooring lines, while the other is moored to the former vessel via an STS (ship-to-ship) mooring system. We obtain hydrodynamic forces using the HOBEM (higher-order boundary element method). Then, we determine their coefficients using the convolution function method in the time domain. We model the catenary mooring lines using the finite element method, and the STS mooring lines are treated as linear SPs (springs) with constraints. To optimize the STS system, we conduct parametric studies on STS mooring systems. Finally, we compare the motion and structural responses of the initial and modified configurations.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51279130 and 51479134)
文摘Freak wave is the common wave which has significant wave height and irregular wave shape, and it is easy to damage offshore structure extremely. The FPSOs(Floating Production Storage and Offloading) suffer from the environment loads, including the freak wave. The freak waves were generated based on the improved phase modulation model, and the coupling model of FPSO-SPM(Single Point Mooring) was established by considering internal-turret FPSO and its mooring system. The dynamic response characteristics of both FPSO and SPM affected by the freak wave were analyzed in the time domain. According to the results, the freak waves generated by original phase modulation model mainly affect the 2nd-order wave loads. However, the freak waves which are generated by random frequencies phase modulation model affect both 1st-order and 2nd-order wave loads on FPSO. What is more, compared with the irregular waves, the dynamic responses of mooring system are larger in the freak waves, but its amplitude lags behind the peak of the freak wave.
文摘In this study, we perform a series of numerical calculations on two vessels in the time domain. One vessel maintains its position using an internal turret and catenary mooring lines, while the other is moored to the former vessel via an STS (ship-to-ship) mooring system. We obtain hydrodynamic forces using the HOBEM (higher-order boundary element method). Then, we determine their coefficients using the convolution function method in the time domain. We model the catenary mooring lines using the finite element method, and the STS mooring lines are treated as linear SPs (springs) with constraints. To optimize the STS system, we conduct parametric studies on STS mooring systems. Finally, we compare the motion and structural responses of the initial and modified configurations.