Study on influencing factors of hydrodynamics based on AUV docking with conical dock

It is necessary to investigate the dynamic performance during autonomous underwater vehicle (AUV) underwater docking to aid in control and to enhance docking safety. Therefore, in this study, the docking hydrodynamic characteristics (including the docking system’s streamline, velocity vector, and surface pressure during the overall docking process) of the AUV with conical hood dock are determined by using the dynamic grid technology, and the water drag force situations of the AUV docking with conical hood dock are studied from the perspectives of different velocities, accelerations, navigation modes, and structures. Additionally, the multiple nonlinear regression fits and the preliminary docking test were examined. Furthermore, brief inferences obtained are as follows: First, the maximum pressure is situated at the upstream surface of the dock conical hood and the head of the AUV, and the maximum rotation angle of the streamline is situated at the outermost ring of dock conical hood. Within a specified range, the rotation angle of the streamline affected by the conical hood progressively declines as the AUV docks deeper into the conical hood. Second, low velocity uniform docking, deceleration docking, and chase docking can reduce the drag force to a certain extent during docking. Finally, both arc shape and mesh structure can decrease the water drag force of docking to a specified degree. This research provides a theoretical basis and reference methods for the dynamic research of the docking system, and other related research can be carried out through the methods and results of this research.