Session: 15-01-02 Seakeeping and Operability

Submission Number: 181942

Numerical Investigation of Scale Effects on CFPSO Hydrodynamic Responses Under Irregular Waves 

Floating Production Storage and Offloading (FPSO) units play a critical role in offshore oil and gas production, where understanding their hydrodynamic behavior under complex sea states is essential for safe operation. In model tests and numerical analyses, the accuracy of predicting the hydrodynamic performance of FPSOs is often influenced by scale effects. To better understand these effects, this study presents a numerical investigation of the scale effects on the hydrodynamic responses of an FPSO under irregular wave conditions. A series of CFD simulations are performed for four geometrically scaled models at 1:1, 1:20, 1:40, and 1:60 scales based on Froude similarity, using a free-surface capturing approach to resolve complex wave–structure interactions under large irregular waves. The results indicate that the overall motion responses are generally consistent across different scales, with most statistical indicators showing limited variation. For surge motion, the overall variation between the maximum and minimum amplitudes is limited, although the time-averaged value shows a larger discrepancy of up to 30%. The statistical values of heave and pitch motions exhibit relatively small differences across all scales. Meanwhile, both the wave and mooring loads remain within the same order of magnitude. Under such irregular wave conditions, green-water and slamming phenomena are observed, which are of particular concern in engineering practice. The occurrence of green-water events exhibits consistent timing when converted to full scale, although the flow characteristics of the green water differ among scales. In the smaller-scale cases, the green-water phenomena appear more intense and cover a larger portion of the deck area. The slamming pressures at various locations show similar magnitudes across scales. Overall, this study investigates the scale effects on the hydrodynamic responses of FPSOs using CFD simulations, and the obtained results offer valuable references for future model experiments and engineering applications, enhancing the understanding of hydrodynamic scaling effects for floating offshore structures.

Presenting Author: Mingqiu Liu Shanghai Jiao Tong University

Presenting Author Biography: Mr Mingqiu Liu is PhD student supervised by Prof. Decheng Wan of Shanghai Jiao Tong University.

Authors:

Mingqiu Liu Shanghai Jiao Tong University
Maokun Ye Shanghai Jiao Tong University
Shenglei Fu CNOOC Research Institute, Beijing, China
Decheng Wan Shanghai Jiao Tong University