Calculation and design of a Podjet-type hanging waterjet nozzle (size 330) = Nghiên cứu tính toán và thiết kế ống phụt kiểu treo Podjet size 330

Abstract

This paper presents the calculation, design, and hydrodynamic evaluation of a Podjet-type hanging waterjet nozzle (size 330) for amphibious vehicle propulsion systems. The study combines theoretical analysis with computational fluid dynamics simulation. A three-dimensional model of the nozzle, impeller, and flow domains was developed in SolidWorks, while CFD analysis was performed using SolidWorks Flow Simulation based on the Reynolds-averaged Navier–Stokes equations and a two-equation turbulence model. The theoretical model was used for preliminary performance estimation, whereas CFD simulations evaluated thrust and power under bollard-pull and forward-speed conditions. At an impeller speed of 2088 rpm, the CFD model predicted a maximum thrust of approximately 7.869 kN and shaft power of 57.4 kW, with deviations of 4.3% and 6.5%, respectively, from MJP330 manufacturer data. Under forward-speed conditions, thrust generally decreased as vehicle velocity increased, while deviations remained generally within 10%. The results support the feasibility of domestic design and provide a basis for further geometric optimization and experimental validation.