Research on optimisation design of cavitation noise of pump-jet propulsion

The pump-jet propulsion is a low-noise propeller device for underwater navigation consisting of a duct, a rotor, and a front stator. Its high design speed, which predisposes the rotor to cavitation and negatively impacts its noise performance, and the presence of numerous parameters for each component render the design complex. This paper aims to develop an automated multi-performance optimisation system for pump-jet propulsions. The system integrates curve fitting of characteristic parameters and full-parameter modelling to achieve an automated workflow between the design, simulation, and optimisation processes. The parameters within the fully parameterised pump-jet propulsion system, which influence its hydrodynamic performance, cavitation performance, and noise performance, are selected as optimisation design variables. Performance in terms of cavitation noise and hydrodynamics is chosen as the optimisation goal function. We set the torque and unsteady force of the propeller as constraints, thereby establishing a multi-objective optimisation design methodology for pump-jet propulsions. Compared to traditional optimisation methods, which typically modify only a few geometric variables, the approach presented in this paper rapidly identifies potential optimal solution regions within a complex, fully parameterised design space. It offers comprehensive evaluations of cavitation noise and hydrodynamic performance from multiple perspectives, effectively addressing the trade-off between noise reduction and efficiency often encountered in conventional designs.