Application of CFD to optimize the design of twin-pod autonomous underwater vehicle

This study explores the hydrodynamic characteristics of a distinctive unmanned underwater vehicle, the Twin-Pod Autonomous Underwater Vehicle (TPAUV). The TPAUV is composed of two torpedo-shaped buoyant bodies connected by a fixed wing and equipped with a propulsion system that includes two buoyancy engines and two thrusters. This innovative configuration allows the vehicle to move with exceptional versatility, maneuvering effectively in both vertical and horizontal directions. As such, the TPAUV is particularly suited for low-speed seabed survey missions, which require stability, precision, and efficient energy use in challenging underwater environments. To evaluate the TPAUV’s performance, the study employed advanced three-dimensional Computational Fluid Dynamics (CFD) simulations to perform a detailed analysis of its hydrodynamic properties. The analysis focused particularly on the turbulent flow generated by the propellers, which significantly influences vehicle behavior and energy efficiency. By assessing how fluid flow interacts with the vehicle’s structural components, the study aimed to optimize the TPAUV’s hydrodynamic performance while minimizing potential drag and turbulence-related inefficiencies. A standout feature of the TPAUV design is its ability to achieve a substantial separation between the center of gravity (CG) and the center of buoyancy (CB), ensuring exceptional stability during submerged operations. This feature is crucial for maintaining precise control and orientation, especially during complex seabed exploration tasks. Additionally, the study examined the hydrodynamic interactions between the two hulls, identifying both beneficial and adverse effects on the vehicle’s overall performance. Variables such as hull dimensions, shape effects, and the vehicle’s operating depth were investigated to better understand their influence on hydrodynamic interactions. Additionally, the relationship between drag force, lift force, and velocity, as well as the variation of hydrodynamic drag force over time, is also discussed in the study. The study highlighted specific areas where these interactions had the greatest and least impact, offering valuable insights into improving the TPAUV’s design. These findings not only validate the feasibility of the TPAUV’s unique configuration but also provide practical recommendations for enhancing the stability, efficiency, and reliability of underwater survey vehicles. This research serves as a foundational step toward advancing the design and control strategies of next-generation autonomous underwater vehicles.