Numerical and Experimental Studies of Seakeeping Performance on a Novel Semi-submersible Transport Ship in Regular and Irregular Head Waves

A novel semi-submersible transport ship is proposed in this paper. This ship has a large well dock, is designed for picking up and transporting a damaged ship, has repair facilities, and serves as a dry dock. The main purpose of this study is to investigate the seakeeping performance of the ship, especially under semi-submerged conditions corresponding to the initial stage of the docking process. First, ship motion responses in regular and irregular waves under normal conditions are investigated, where the three-dimensional free surface Green's function method is used for numerical analysis. Secondly, similar studies have been conducted in the semi-submerged state, where the hybrid boundary element analysis method is introduced for numerical analysis because the interaction between the two fluid domains, the inner and outer domains around the hull must be considered. In addition to the development of computational codes, experimental studies are carried out using a ship model in the wave tank. The experiments are conducted under normal and semi-submerged drafts at zero speed in regular and irregular head waves. As a result, the experimental study's findings are consistent with the numerical calculation results.