Mooring System Influence on the Response of Floating Breakwaters

Abstract Floating breakwaters are increasingly used as effective structures for wave attenuation in, for instance, marinas, ports, fragile beaches, and coastlines. The choice of the mooring system plays a crucial role in determining their characteristics, such as dynamic behavior under waves and wave transmission. This study investigates the influence of different mooring system configurations on the dynamic behavior of floating breakwaters. Three types of mooring systems are compared: (1) taut, (2) slack, and (3) hybrid. First, the hydrodynamic characteristics of the breakwaters are obtained using the OrcaWave software, a 3D diffraction/radiation software based on the potential theory for wave-body interactions. A first model is developed to be validated against experimental data from the literature. After that, a series of time-domain numerical simulations are carried out using the OrcaFlex software, where the mooring systems are modeled. Finally, the numerical tests are assessed. The results indicate that when considering only the mooring forces, the slack mooring system is the best option, which has very low mooring forces when compared to the taut and hybrid mooring systems. Also, due to the high load peaks, it is hard to consider the use of the hybrid mooring system. Furthermore, when considering the motion responses, the best option is the taut mooring system, which has a very small heave response. These findings provide insights into the design and selection of mooring systems in floating breakwater applications, enhancing their performance.