Research on Coupling Characteristics of AUV Hydrodynamic and Motion Response Under Turbulent Flow Induced by Underwater Dune

Abstract As marine resources continue to be extensively developed, Autonomous Underwater Vehicles (AUVs) have emerged as powerful tools for ocean exploration. In tasks such as near-seabed detection, AUVs are required to operate in close proximity to the seabed. The complex terrain of the seabed amplifies the turbulent characteristics of near-seabed flow fields, affecting the hydrodynamic performance of AUVs. The continuously changing turbulent field induces fluctuations in AUV hydrodynamic coefficients, subsequently influencing the stability of AUV navigation. This study focuses on a typical dune terrain and employs the Large Eddy Simulation (LES) method to simulate the flow field near the dune, calculating the hydrodynamic parameters of AUVs. To obtain the navigation path of AUV in the complex flow field around the terrain and analyze AUV motion stability, a combination of the Dynamic Fluid Body Interaction (DFBI) method and the overset grid method is utilized. This approach releases the three degrees of freedom in AUV motion, emphasizing translational displacements in the Cartesian coordinates, as well as pitch phenomena during AUV’s motion. The results provide insights into hydrodynamic changes during AUV navigation and motion deviation trajectories. The findings serve as a reference for the maneuverability performance of AUVs.