Hydrodynamic analysis of a tethered underwater robot with control equipment subjected to cnoidal waves

This paper investigates the manoeuvrability and hydrodynamic performance of a tethered underwater robot with control equipment, considering the cnoidal wave effect. A tethered underwater robot installed with two hydrofoils and ducted propellers is proposed to investigate the related phenomena. The numerical experiment is based on combining a variety of computational fluid dynamics (CFD) techniques, such as overlapping grids, sliding meshes, and six-degrees-of-freedom models. The reliability of the numerical method is verified by the experiment with the tethered underwater robot. The numerical results show that the hydrodynamic performance of the tethered underwater robot in shallow water conditions is significantly influenced by the cnoidal wave. The control effect of the control equipment is also significantly affected by the cnoidal wave.