Numerical Research on Excitation Force Characteristics of Pre-Swirl Stator–Propeller–Rudder System

The present study conducts numerical simulations to investigate the excitation force characteristics of a pre-swirl stator–propeller–rudder system and analyzes the potential benefits of the combined pre-swirl stator and rudder bulb for vibration and noise based on force and pressure fluctuations. The propeller bearing force, rudder force and hull surface pressure are compared and analyzed under conditions with and without energy-saving devices. The results show that the pre-swirl stator and rudder bulb intensify the axial load pulsation of the propeller, which may affect the service life of the main engine and gearbox. The overall level of lateral load pulsation is also increased, which may lead to higher cabin noise. The load pulsation level of the pre-swirl stator is comparable to that of the propeller bearing force, while the increased vibration of the rudder may result in more complex structural safety and noise issues. The reduction in hull surface pressure fluctuation contributes to the mitigation of the low-frequency underwater radiated noise. The influence mechanism of the pre-swirl stator–rudder bulb on the excitation force is of great significance to the ship engineering design.