Numerical investigation of hydrodynamic characteristics of a dual floating breakwater

Individual floating breakwaters have a limited effect on wave dissipation, especially for long waves. However, consideration of utilizing dual floating breakwaters (FBs) can significantly improve wave dissipation performance. The complex interaction mechanism between waves and dual FBs is poorly understood. The current study considers four different combinations of dual FBs, each focusing differently on their wave dissipation performance and interaction mechanisms. The breakwater spacing, relative density, and incident wave period of the dual FBs are employed as study parameters to further analyze their performance in detail. Furthermore, the appropriate application of smooth particle hydrodynamics (SPH) is applied, and the discussion in Bragg resonance reflection of water waves by the dual FBs is given. Results demonstrate that the optimum spacing of the dual FBs is 0.7 times the wavelength. In addition, the dual rectangular FB also indicates good performance when the incident wave condition is at low frequency. Moreover, the transmission coefficient of the dual rectangular FB is approximately 0.4 of that of the corresponding isolated FB, and the occurrence of Bragg resonance reflection is possible between the waves and the dual FBs. This study can provide constructive research value for future practical marine engineering applications.