Investigation on Optimization Design of High-Thrust-Efficiency Pump Jet Based on Orthogonal Method

Abstract

Compared with traditional propellers, the pump jet has the characteristics of low noise, large thrust, and high efficiency, which is widely used in underwater ships, unmanned underwater vehicles, and underwater rescue equipment. It is difficult to design and evaluate the performance of a pump jet because of its complex structure and the many changes in its component parameters. In this paper, high-efficiency pump jet design and optimization methods are presented. Based on the center-of-gravity accumulation line control, a design method is proposed to design the pump jet rotor. The thrust performance and hydraulic performance of the pump jet are obtained through numerical simulation, and the influence of various parameters on performance is studied. Finally, based on a single-factor analysis and orthogonal optimization, a multi-parameter orthogonal optimization of pump jet was carried out. The angle of attack, chord length, camber angle, and number of blades were selected to establish a four-factor and three-level orthogonal table. The thrust efficiency was taken as the optimization goal. Compared to the original pump jet, the optimized pump jet thrust coefficient and thrust efficiency are significantly improved at various speed conditions, with the maximum thrust efficiency increased by 7.23%, meeting the design requirements. This research provides a theoretical basis and technical guidance for the structural optimization design of a pump jet propulsion system.

Keywords

• pump jet
• barycenter stack line
• thrust efficiency
• orthogonal optimization