Hydrodynamic performance of a novel dual floating protective device

Individual floating breakwaters have limited impact on wave dissipation, particularly concerning medium- and long-period waves. However, the incorporation of a dual floating breakwater significantly enhances wave dissipation performance. This study introduces a novel design—a dual floating protective device—aimed at enhancing both wave dissipation and current attenuation. The hydrodynamic behavior of this dual floating protective device is rigorously examined through experimental investigations conducted using a large wave-current flume. A comprehensive sensitivity analysis of key parameters, including relative draft, spacing between floats, and wave-current characteristics, is performed to explore their effects under regular and irregular wave conditions, as well as combined wave-current coupling action. Additionally, the appropriate application of particle image velocimetry is utilized, and a discussion of current field and water particle velocity vectors in front of, within, and behind the dual floating protective device is provided. The results indicate that the wave dissipation performance of the dual floating protective device can be enhanced by 125.4% under regular wave-current interactions. Notably, when the spacing of the dual floating protective device is adjusted to twice, once, or two-thirds of the wavelength, superior attenuation capabilities are observed. The current transmission coefficient of the dual floating protective device initially increases before decreasing as current velocity rises. Furthermore, under the influence of mid- to long-period waves, significant coupling and collision phenomena occur between the dual floating protective devices, endowing it with robust capabilities for attenuating such waves. This study provides valuable insights for future practical applications in the field of marine engineering.