Cavitation on the pump jet pre swirl type due to changes in the stator chord length

This paper investigates the open water impact of stator hydrofoil chord length on the hydrodynamic and cavitation performance of a pre-swirl pump jet. Five geometries with stator chord lengths 0.14–0.18 of rotor diameter were generated using a direct design method and analyzed using CFD (Computational Fluid Dynamics) with k-ω SST (Shear Stress Transport) turbulence model and the Schnerr–Sauer cavitation model. The numerical results were validated using the INSEAN E779A propeller data. The results show that increasing the stator hydrofoil chord length positively impacts the hydrodynamic and cavitation performance of the pump jet. Increasing the chord length leads to an increase in the maximum open water efficiency, a decrease in the cavitation area, and an increase in the low-pressure area on the suction side of the rotor. It also causes a more uniform pressure distribution on the rotor. Among the investigated cases, the maximum open water efficiency of 64.51% was obtained for the L = 0.18DR case, while the minimum efficiency of 63.53% was obtained for the L = 0.15DR case. Based on the other simulation results, the L = 0.18DR case appears superior to the others.