Hydrodynamic design and analysis of a hybrid-driven underwater vehicle with ultra-wide speed range

Abstract

This paper presents a hybrid-driven underwater vehicle with ultra-wide speed range, which combines the conventional autonomous underwater glider with a shaftless propeller. By designs of low-resistance structures in wide speed range, the vehicle has a low-speed gliding mode within 3 kn driven by buoyancy, and a low-medium-high speed navigation mode up to 30 kn driven by the propeller. In order to analyze the effectiveness of the structure designs, an analysis method of the flow energy dissipation (FED) is proposed. By solving the cumulative function of the FED, this method can quantitatively characterize the influence of the vehicle's local structures on navigation power consumption. On this basis, the hydrodynamic numerical models for the two modes are established by the computational fluid dynamics (CFD) methods. The numerical analysis indicates that this vehicle has a good lift-drag ratio in glide mode and a superior fluidity in propelled mode. It can maintain low resistance and low power consumption in both modes. Finally, the numerical models are verified to be accurate by prototype tests. This vehicle can provide reference for the designs of the integrated underwater platform with wide speed range and multi missions.