Propeller hydrodynamic and flow noise characteristics during underwater maneuvering

Navigation of naval equipment in complex ocean environments is influenced by various factors such as underwater obstacles. Reasonably adjusting the navigation strategy is of great significance for enhancing the equipment's stealth and stability. During navigation, attitude adjustments can alter the circumferential flow field and acoustic characteristics of the propeller. Quantifying the impact of inflow state changes on the hydrodynamic and flow noise characteristics of the propeller plays a crucial role in guiding the improvement of its overall acoustic performance and the optimization of navigation strategies. In this study, time-domain inflow boundary conditions were established based on motion decomposition combined with trigonometric functions to accurately simulate the inflow characteristics of the propeller during the naval equipment attitude adjustment process. In this study, the computational fluid dynamics/computational aero acoustics hybrid numerical method was employed to obtain the hydrodynamic and flow noise characteristics of the propeller under different advanced coefficients in motion. The results indicate that under the combined effect of axial and vertical transient inflows, the propeller flow field structure exhibits a shift. In the sound pressure level spectrum, certain peaks within the 10BPF (blade passing frequency) frequencies range disappear and reappear, while flow noise excitation phenomena are observed at 22BPF and 23BPF frequencies. The above research results play an important role in the optimization of propeller parameters and navigation strategies.