Hydroelastic performance of a flexible pontoon-type floating breakwater embedded with multiple oscillating-water-column devices

Combining Wave Energy Converters (WECs) with a long-flexible floating breakwater is a plausible pathway to the engineering application of wave energy technologies, which not only enhances energy capture capability but also improves structural stability of breakwater. This study proposes a multi-module flexible pontoon-type floating breakwater integrated with oscillating water column (OWC) units. Each chamber features an independent power take-off (PTO) system for energy capture. A coupled fluid-structure interaction model, integrating Computational Fluid Dynamics (CFD) with Finite Element Method (FEM), is developed to investigate the hydroelastic response. The bi-directional coupled process is realized by satisfying constant boundary conditions between fluid velocity and pressure, and structural node displacements at each time step. Parametric studies demonstrate that flexible structures offer superior adaptability to wave loading compared to rigid counterparts, effectively reducing wave-induced forces while maintaining energy capture. Further analysis reveal that increased structural stiffness enhances internal resonance within chambers, significantly improving capture factors, whereas excessive flexibility can trigger complex multimode radiated wave interactions, adversely affecting energy conversion efficiency. Additionally, incorporating a bottom opening strengthens wave resonance within the chamber, thereby increasing energy dissipation. These findings highlight practical advantages of multi-module flexible floating breakwaters, providing valuable guidelines for design and optimization in engineering applications.