Hydrodynamic Performance of A Floating Breakwater System Under the Terrain of Islands and Reefs: A 3D Experimental Study

With the acceleration of marine construction in China, the exploitation and utilization of resources from islands and reefs are necessary. To prevent and dissipate waves in the process of resource exploitation and utilization, a more effective method is to install floating breakwaters near the terrain of islands and reefs. The terrain around islands and reefs is complex, and waves undergo a series of changes due to the impact of the complex terrain in transmission. It is important to find a suitable location for floating breakwater systems on islands and reefs and investigate how the terrain affects the system’s hydrodynamic performance. This paper introduces a three-cylinder floating breakwater design. The breakwater system consists of 8 units connected by elastic structures and secured by a slack mooring system. To evaluate its effectiveness, a 3D model experiment was conducted in a wave basin. During the experiment, a model resembling the islands and reefs terrain was created on the basis of the water depth map of a specific region in the East China Sea. The transmission coefficients and motion responses of the three-cylinder floating breakwater system were then measured. This was done both in the middle of and behind the islands and reefs terrain. According to the experimental results, the three-cylinder floating breakwater system performs better in terms of hydrodynamics when it is placed behind the terrain of islands and reefs than in the middle of the same terrain.