To address the lightweight and vibration reduction needs of pump-jet propulsors, this study proposes the use of carbon fiber-reinforced composites （CFRC） in propulsor ducts.

First, a two-way CFD/FEM fluid-structure interaction （FSI） method was developed to capture structural responses caused by hydrodynamic forces. This enabled a systematic analysis of the effects of structural deformation on both hydrodynamic performance and shaft excitation characteristics. Subsequently, a duct model was developed to investigate the impact of the composite material on hydrodynamic performance, vibration transmission mechanisms, and structural responses.

Composite ducts exhibited structural deformations of 10⁻⁷ m, indicating a negligible impact on hydrodynamic performance. The natural frequencies of the first four wet modes showed a 65.3%—80.2% reduction compared to the corresponding dry modes. Vibration analysis revealed a 1.0533 dB reduction in total acceleration level at stator-duct connections compared to bronze alloy ducts, though a slight rebound in vibration performance was observed under internal surface excitation.

The study strongly confirms the role of composites in lightweight design, vibration reduction, and performance optimization, providing a basis for propulsor design.

Composite materials offer advantages such as low weight, corrosion resistance and a high damping ratio. To enhance the overall performance of underwater vehicles, this study investigates the characteristics of a composite rotor pump-jet propulsor.

Firstly, by combining computational fluid dynamics (CFD) and the finite element method (FEM), a two-way fluid-structure interaction method and a flow-induced noise prediction method were established based on FW−H equation for the composite rotor pump-jet propulsor. The open water performance, structural response and flow-induced noise characteristics of the composite rotor pump-jet propulsor were then analyzed under various operating conditions.

The results show that with the increase in advance speed coefficient, the structural deformation and stress and strain levels of the composite pump-jet propulsor rotor decrease. The overall sound pressure level of flow-induced noise first decreases and then increases, reaching a minimum of 87.60 dB at J = 0.8. Compared with a traditional aluminum alloy pump-jet propulsor, the rotor deformation of the model-scale composite pump-jet propulsor is minimal. It does not affect the hydrodynamic shape or cause significant changes in hydrodynamic performance. The flow-induced noise of composite pump-jet propulsor is reduced slightly at specific frequencies, and the overall reduction in sound pressure level is also relatively limited.

These research findings provide a theoretical basis for the comprehensive performance optimization of pump-jet propulsors, including weight reduction and noise control design.