When an Underwater Vehicle (UV) moves close to the seabed, the interaction of flow field between the UV and the seabed adversely affects its operation safety. In order to predict the evolution of the hydrodynamic performance of the UV and flow field characteristics in the vicinity of UV under the influence of the seabed, in the paper, the flow field near the seabed was numerically simulated using computational fluid dynamics (CFD) method. The influence of the flat seabed topography on the UV is first studied, and the submarine sand waves topography were further analyzed. The results show that within a certain range from the seabed, the drag and attractive force of the UV will increase, and continuous changes of seabed topography has a significant influence on the UV.
With the rapid development of science and technology and marine equipment, human exploration of oceans has gradually stepped from shallow to deep. UVs have been widely used in the mapping of seabed topography and geomorphology, seabed tracking and detection, submarine oil and gas pipeline inspection, submarine cable burying and maintenance, etc. (Panda et al., 2021). However, when the UV operates near the seabed, compared with the unbounded domain, the seabed will change the flow field around the UV, which will interfere with the hydrodynamic performance of the UV and affect the operation safety (Korol et al., 2016). In addition, the seabed topography is complex, the change of topography will have a more significant and unpredictable influence on the safety of the UV navigating near the seabed. In the case of insufficient research on the hydrodynamic interference of the seabed to UVs at present, in order to avoid the risk of collision, in the uses of UVs mentioned above, usually they are limited to a certain distance from the seabed, which affects the operation accuracy. Therefore, for UVs operating close to the seabed, it is of interest to investigate the influence of the seabed on the hydrodynamic performance of them.