Hydrodynamic Investigation on the Cantilevering Oscillating Buoy Type WEC Integrated into a Floating Dock

The hybrid system consisting of an Oscillating Buoy and a floating dock provides a promising solution for wave energy conversion and power supply of marine vehicles. In this paper, a floating dock station (FDS) combined with a cantilevering oscillating buoy (COB) was proposed. The COB is hinged to the floating dock and helps to generate the electric power by relative movement between the COB and FDS. Based on the potential flow theory, a three-dimensional model was set up in the AQWA software to investigate the hydrodynamic characteristics of this proposed hybrid system. In this paper, the effects of wave conditions and geometric properties of the FDS-COB device were studied and optimized to improve the power capture performance of the hybrid system. The results show that the device achieves a high wave energy conversion efficiency of 44.3% due to the pitch and roll motions of the main floating body, compared with the traditional fixed dock platform. Furthermore, the effects of the cantilever angle and float length of the COB were studied to optimize certain geometrical parameters. The property of the efficiency mitigation with the higher cantilever angle and the smaller cantilever length should be avoided while designing such a system.