Hydrodynamic characteristics and parametric optimizations of a hybrid system combining a hinged wave energy converter and a breakwater with a semi-opened moonpool
Fukai Song, Yong Cheng, Saishuai Dai, Zhiming Yuan, Atilla İncecik
Abstract
Bird’s view of the WEC-breakwater hybrid system. • A novel hybrid system combining a hinged WEC and a breakwater with a semi-opened moonpool is proposed. • The wave power absorption demonstrated a broader effective frequency bandwidth and a higher capture width ratio. • Deper WEC drafts have a strong retardation effect on long waves.The symmetric bottom WEC has more outstanding energy conversion performance. Combining a Wave Energy Converter (WEC) with a floating breakwater to enhance both wave attenuation and the energy capture performance is a plausible pathway to commercializing wave energy technologies. The research introduced a new integrated system that merges a hinged wave energy converter and a breakwater with a semi-opened moonpool. Both the breakwater and the WEC were investigated using multi-Degrees-of-Freedom (DOF) to incorporate a realistic coupling between the two. These two systems were connected through an articulated Power-Take-Off mechanism, and power was harnessed through their relative pitching motion induced by wave loads. The study utilized the Finite Volume Method (FVM) to develop a three-dimensional (3-D) numerical wave tank (NWT) and analyzed the hydrodynamic characteristics of the proposed hybrid system under regular wave loading. Subsequently, design parameters of the two devices, such as the length of the breakwater caisson and the bottom shape of the WEC, were optimized to improve the system's performance. The results indicated that the combination of the two devices enhanced both wave attenuation and energy conversion capacity, compared to using a standalone WEC or breakwater. Notably, the wave power absorption demonstrated a broader effective frequency bandwidth and a higher capture width ratio.