Study on the Thrust Characteristics of Vector Thrusters Under Complex Inclination Angle Variations

A parallel-type vector thruster was designed, and its dynamic performance was systematically investigated using a combination of mechanical structural analysis, numerical calculations, and experimental methods. First, a thrust model of the vector thruster was established, and its mechanical structural characteristics were analyzed. Subsequently, the governing equations were discretized and solved using computational fluid dynamics (CFD), and a numerical model of the thruster’s viscous flow field at different inclination angles was established based on the moving reference frame (MRF) method. Furthermore, the structural forces, wake effects, and hydrodynamic performance of the thruster under different rotational speeds and inclination angles were analyzed using the control variable method. Finally, the thrust performance was tested using an underwater dynamic test rig, and the experimental results were compared and analyzed with the theoretical calculations. The results suggest that as the propeller’s inclination angle increases, the low-pressure region on the thruster tends to expand, which appears to intensify cavitation and vortex phenomena and leads to a more uneven wake distribution. These effects are correlated with a reduction in propulsion efficiency, which was observed to increase nonlinearly with rotational speed, potentially influencing the thruster’s operational performance. The study elucidates the influence mechanism of steering mechanism stiffness on the propulsion characteristics of spatially moving propellers, providing a foundation for future model-based control design in vector thrust systems.