Hydrodynamic analysis of an aquaculture tank-type floating breakwater integrated with perforated baffles

Abstract

An innovative approach that integrates the floating breakwater (FB) with an offshore aquaculture tank is proposed to enhance economic benefits and hydrodynamic properties. To study the hydrodynamics of the integrated structure, a time-synchronized spatial-separated strategy is proposed and applied to the computational fluid dynamics (CFD) to facilitate the complex coupling between waves, mooring force, sloshing flow with the perforated baffle, and body motion. The mooring constraint was achieved by incorporating the catenary mooring theory, as well as employing the volume-averaged porous theory to simulate the perforated baffle effect to provide a low-energy environment required by aquaculture. Corresponding experimental tests were conducted to validate the reliability of the numerical model. The motion response, transmission and reflection coefficients, and sloshing behavior are analyzed to evaluate the hydrodynamics of the integrated structure. Besides, an index referred to as area-weighted-average velocity is introduced to further quantify the kinetic energy of sloshing flow. Results reveal the proposed aquaculture tank-type floating breakwater (AFB) can serve well as tuned liquid dampers (TLDs) to reduce the roll motion, and greatly improve the wave-attenuating capacity. Furthermore, the perforated baffles effectively weaken the sloshing energy at medium and finite filling depths, which are commonly operating depths for aquaculture in a floating closed containment system (FCCS). Overall, the floating breakwater integrated with the aquaculture tank is feasible due to a series of advantages.