Hydrodynamic interactions on sway motions and drift forces between shuttle tanker and FPSO arranged side-by-side

In this paper, hydrodynamic interactions were studied between two floating bodies positioned side-by-side as a shuttle tanker-FPSO (floating production, storage and offloading) system. Particular interest is placed on the sway coupled motions and mean drift forces with different separation distances and various wave directions. The results show that the hydrodynamics between two vessels is obviously distinguished from the single body case with shielding and exaggerating effects. In addition, the sway mean drift forces of multiple body case experience variations in both magnitude and direction compared with the single body case. As the sway motion is one of the most crucial components considered in DP (dynamic positioning) system, getting a better perspective of the sway motion is beneficial for both the control of a shuttle tanker with DP system and the prediction of behavior of the vessels for safe operation. This paper is helpful to both prudent designs in the basic design stage and operations in engineering practice.