Effects of the current-wave interaction on a cylinder platform

This article investigates the motion responses of floating production storage and offloading systems (FPSO) under wave-current interactions. Experiments were conducted on a cylindrical FPSO in a wave-current combined wave basin. Two methods were employed to compare the effects of currents: applying an equivalent force to a specific location in the platform and generating real currents in the basin. The primary objective of this study is to explore the sensitivity characteristics of the platform's dynamic response in the presence of wave-current coupling. The findings reveal significant phase shifts in the low-frequency motions of the sway and pitch responses due to the interaction between waves and currents. Moreover, the six degree-of-freedom motions of the platform experience amplified overall energies in both low-frequency and wave-frequency motions. A notable observation is that wave-current interaction leads to a considerable increase in surge motion amplitude, even when the reduced velocities are smaller than the lock-in region.