Abstract: With SST turbulent model, non-cavitating hydrodynamic performance of a mixed-flow waterjet is obtained by calculating RANS equations. The comparison between calculation results and data from manufacturer shows that the numerical model and method is creditable. The cavitating hydrodynamic performance of it is calculated and analyzed with mixture homogeneous flow cavitation model based on Rayleigh-Plesset equations. Numerical results, such as power and thrust, have good accordance with manufacturer’s data. The critical IVR when cavitation occurs is obtained. The calculation results show that mass flow rate and total head of the pump are reduced when cavitation occurs on the blades, and thrust declined. The cavitation on blades gets much severer as IVR falls under constant power condition. Inlet duct cavitation lags behind the blade cavitation, and the nozzle cavitation in form of spatial cavitation occurs ahead of the blade cavitation, but there is no cavitation on nozzle wall. The results also prove that the limiting cavitation line is a constant suction specific speed line, and their values are approximate to 1 280, 1 390 and 1 580.

Key words: Cavitation, Computational fluid dynamics, Inlet velocity ratio, Mixed-flow pump, Suction specific speed, Waterjet