Abstract:Propulsion performance is one of the most important properties of underwater vehicles, and underwater vector propulsion technology is the best choice for high-performance underwater vehicles in the future due to its all-round propulsion control, efficient propulsion efficiency, low vibration and noise levels. Considering the requirements of variable load of high-speed navigation and low-speed maneuvering, this paper proposes a “2+4” variable-load multi-axis vector propulsion layout, which can achieve efficient propulsion at high speed and high maneuverability at low speed by changing the directions of thrusters. Based on computational fluid dynamics (CFD), the hydrodynamic characteristics of the unmanned underwater vehicle (UUV) equipped with this new propulsion layout under cruise and oblique navigation and the effect of thruster deflection on the hydrodynamic performance of UUV were studied. Our results showed that the drag and rotation speed showed a parabolic relationship under high-speed cruise conditions; the oblique navigation and the deflection of the bow thruster had a significant effect on the vertical force and pitching moment of the whole UUV, and the wake of front thrusters would weaken the performance of the rear thrusters; the retraction of rear thrusters had little effect on the hydrodynamic forces of UUV, but can provide additional control torques. The research of this work can provide an important reference for the optimal design of the propulsion mode and layout of high-performance underwater vehicles, and can be used as a guiding direction for the future improvement of the new UUV.