The current study focuses on the cavitation jet characteristics of the jet nozzle for ship cleaning under different water depths. The nozzle of a dual-chamber self-excited oscillation pulsed jet nozzle is numerically studied under four depths of 10m, 25m, 50m and 100m by using the Rayleigh-Plesset cavitation model. The cavitation degree, fluid velocity distribution and turbulent kinetic energy distribution of the nozzle under different water depths are studied and analyzed. The results indicate that the cavitation in the internal flow field of the dual-chamber self-excited oscillation pulsed jet nozzle is greatest with relatively high fluid velocity and the turbulent kinetic energy is highest in the rear chamber and rear channel. However, the cavitation, fluid velocity and turbulent kinetic energy in the external flow field are significantly reduced. With the increase of the water depth, the internal flow field of the nozzle is almost unaffected, while the external flow field is greatly affected with increased cavitation number and gradually reduced cavitation degree, fluid velocity and turbulent kinetic energy, and thus weakened cavitating cleaning effect. The numerical research method can provide references for the underwater ship cavitation cleaning.

The first domestically produced cruise ship was delivered by the end of 2023, and it is expected that the cruise industry will make significant contributions to the Chinese economy in the future. However, Chinese enterprises still have a long way to go in terms of the independent design of cruise ships, with necessity to consider the future development and to design and arrange in advance. As an entertainment vehicle, the cruise ship should meet the customization needs of different regions and cultures. Any changes will bring huge costs to the design of the cruise ship due to the system complexity. The composition of functional modules and feasibility of customized design for large cruise ships are firstly analyzed to solve this problem. Then, a modular product family design method and a procedure of the customized design based on the product family are proposed for the large cruise ship. It can provide support for the independent design of domestic large cruise ships in the future.