Coupled Effects of Incident Waves Forcing and Internal Tank Sloshing on the Dynamics of Twin Floating Bodies

The growing demand for ocean space has generated significant interest in multi-body floating systems, where gap resonance in confined regions plays a critical role in ensuring the safety of offshore operations. This study develops a numerical tank model using the Smoothed Particle Hydrodynamics (SPH) method, implemented through the open-source code DualSPHysics, to investigate hydrodynamic resonance in a twin-floater system and to examine the influence of internal tank sloshing on its hydrodynamic characteristics. The hydrodynamic behavior of the gap flow between a fixed twin-floater system in the numerical tank is validated through systematic comparison with experimental data. Subsequently, the wave-induced motions and forces on a twin-floater system are compared with those on a single floater. Furthermore, the effects of internal tank sloshing on the hydrodynamic response of the twin-floater system are explored. A parametric study is conducted to analyze the influence of incident wave frequency on floater motion and tank sloshing dynamics. The results show that the presence of an internal tank can significantly reduce pitch motion and vertical forces on the floating body, while exerting minimal influence on heave motion and horizontal forces. The findings provide new insights into the hydrodynamic performance of twin-floater systems and their interaction with internal sloshing phenomena.