Dynamics and “falling deep” mechanism of submerged floating body under internal solitary waves

Internal solitary waves (ISWs) can result in notable alterations to the hydrodynamic characteristics of submerged bodies, affecting their motion and even leading to serious “falling deep” accidents. This study utilizes a combination of Computational Fluid Dynamics (CFD) and the modified Korteweg-de Vries (mKdV) theory. By combining techniques such as the Volume of Fluid (VOF) model and overset grid, a numerical method for simulating the interaction between ISWs and submerged bodies is established. The dynamics of submerged floating bodies under internal solitary waves are systematically investigated. The results demonstrate that the primary cause of changes in motion and force is the rotating velocity field induced by ISWs. Additionally, the influences of different locations and internal solitary wave amplitudes on the hydrodynamic characteristics of the submerged body are examined. The submerged body is more likely to experience “falling deep” due to the influence of ISWs when it is situated in the lower layer of the fluid.