Wave Transmission Comparative Assessment of Three-Dimensional Single and Multi-Floating Breakwaters Systems

Abstract Floating breakwaters are widely utilized due to their capacity to protect marinas, ports, fragile beaches from being washed away, and coastlines from erosion. These structures act as wave attenuators, reducing the transmissibility of incident waves. A single-breakwater system may offer simplicity and ease of deployment, but the mooring system may offer some challenges due to the magnitude of the forces involved. On the other hand, multi-breakwater systems may improve this issue and, in addition, provide enhanced wave attenuation. This paper investigates the wave transmission characteristics of a box-type (1) single-breakwater and (2) multi-breakwaters system. A series of numerical simulations are carried out using the OrcaWave software, a 3D diffraction/radiation software based on potential theory for wave-body interactions. The hydrodynamic response of both configurations is analyzed under varying wave conditions. After that, the wave transmission coefficients (Kt) are obtained for sheltered areas of interest. The results highlight significant differences in the wave transmission coefficients between single and multi-unit arrangements, with the latter demonstrating superior performance, i.e., achieving lower wave transmission coefficients. The findings suggest that multi-breakwater systems are, on average, the best alternative when compared to single ones, offering enhanced wave attenuation.