Hydrodynamic performance and layout optimization of floating truncated cylinder wave energy converter arrays in front of a vertical wall under the action of regular and irregular waves

This paper introduces a novel oscillating buoy-type wave energy converter (WEC) in front of a bottom-mounted vertical wall. The cylindrical WEC is capable of oscillating and harnessing wave energy in five degrees of freedom (DOF), designated as a 5-DOF WEC. The hydrodynamic performance of WEC arrays is then methodically examined in both regular and irregular wave conditions. The presence of the bottom-mounted vertical wall substantially enhances the array performance under specific circumstances. In contrast to the 1-DOF WEC, which only oscillates and extracts wave energy in the heave direction, the 5-DOF WEC substantially boosts array performance and expands the absorption bandwidth for both regular and irregular waves. The optimal layouts and associated free surface distributions for four scenarios involving unidirectional regular waves, unidirectional irregular waves, and multidirectional real waves are presented. When compared to the 1-DOF WEC array, the optimal arrangement of the 5-DOF WEC array produces a more pronounced disturbance to the wave field, leading to greater energy absorption. Thus, the collaborative development of the 5-DOF WEC array alongside the vertical wall not only facilitates enhanced wave energy absorption but also effectively mitigates the wave load acting on the vertical wall.