Time-domain analysis of side-by-side floating bodies by the three-dimensional hybrid Green function method

In the present research, the three-dimensional (3D) time-domain hybrid Green function method is developed for simulating the coupled motions of two floating bodies with the side-by-side arrangement in waves. The fluid domain is decomposed into an inner and an outer domain by an imaginary control surface. Then, the Rankine source is adopted in the inner domain, while the transient time domain Green function is adopted in the outer domain. The side-by-side problem is numerically solved by means of the continuity condition adopted on the control surface. A Wigley hull ship and a rectangular barge with the side-by-side arrangement in beam wave are investigated, while the hydrodynamic interactions between them are taken into consideration. Based on that, the coupled motions in waves between a supply ship and frigate both with large flare, as well as with same forward speed and side-by-side arrangement are also investigated. A good agreement is obtained between numerical and experimental results for all case studies, which indicates that the present method and developed time-domain numerical solver is accurate enough and available to handle the side-by-side problem in ship and ocean engineering.