Graylee, Adeleh; Yousefifard, Mahdi
(Scientific Journals Maritime University of Szczecin, Zeszyty Naukowe Akademia Morska w Szczecinie,
)
This paper presents a numerical investigation of the hydrodynamic performance of a modified sandglass-type
FPSO (Floating Production, Storage and Offloading) with different geometrical parameters. The influence of
the roll damping plate on heave and pitch motions of the FPSO was studied in regular waves. To estimate the
hydrodynamic performance and utilize the results on the design stage of the FPSO, the boundary element
method (BEM) was used. Furthermore, the hydrodynamic performance of two cylindrical and sandglass-type
FPSOs under the same conditions was compared in different waves. Five sandglass-type FPSOs with dissimilar
inclination angles were utilized with the constant draft. The effects of different inclination angles, including
various radii of water-plane part of the floating object on hydrodynamic responses and wave forces applied to
the FPSO, were investigated, and presented here. Numerical results were compared against published experimental
data of a sandglass-type model, and good agreement was achieved. Based on the simulation results,
a conclusion that a sandglass-type FPSO with the inclination angle of 35 degrees proposes proper hydrodynamic
performance in both heave and pitch motions for all ranges of wave frequencies was reached. In addition, as
it was predicted, the effect of heading sea on a sandglass-type FPSO was significant compared to other wave
directions. Finally, by adding a damper plate to the floor of the platform, its hydrodynamic performance is
improved. For numerical analysis of the modified FPSO, three different damper sizes are used to investigate its
effect on the reduction of the pitch motion amplitude in waves.