Motion responses and flow field characteristics of a CFPSO with complex heave plates under regular waves

Cylindrical floating production storage and offloading (CFPSO) units are widely recognized as superior platforms in the field of offshore oil and gas engineering. Practical engineering applications show that heave plates not only have significant effects on heave motion, but also exert coupled effects on surge, pitch and slow-drift responses. However, existing academic studies are mostly limited to simple structural configurations, and systematic research on complex heave plates and their influences on multi-degree-of-freedom motions is still insufficient. In this paper, based on the computational fluid dynamics (CFD) method and using the in-house code naoe-FOAM-SJTU, the effects of complex heave plates with serrated protrusions, edge-cutting and openings on the motion performance of a CFPSO are investigated under different wave-facing configurations. The numerical model is calibrated and validated against model test data. Typical operating conditions are determined through free-decay tests, and three characteristic motion patterns are summarized by analyzing the motion responses under six wave-facing configurations. By analyzing the flow field characteristics, the motion response mechanisms are revealed. Additionally, response amplitude operator (RAO) curves for typical wave periods are calculated to verify the general applicability of the conclusions.