Experimental and Numerical Investigation of the Effect of Stator and rotor distance on the Hydrodynamic Performance of a PumpJet Propulsion System

Qaedsharaf, Mohammad Hussein; Yari, Ehsan; Dehghan Manshadi, Mojtaba

doi:10.22034/ijcoe.2026.558002.1204

Experimental and Numerical Investigation of the Effect of Stator and rotor distance on the Hydrodynamic Performance of a PumpJet Propulsion System

Articles in Press

Document Type : Original Research Article

Authors

Mohammad Hussein Qaedsharaf ¹

Ehsan Yari ²

Mojtaba Dehghan Manshadi ³

¹ Ph.D in Mechanical Engineering, Khatam Al-Anbia Air Defense University

² Assistant Professor, Faculty of Mechanical Engineering, Malek-Ashtar University of Technology; Iran, Isfahan

³ Professor, Faculty of Mechanical Engineering, Malek-Ashtar University of Technology; Iran, Isfahan

10.22034/ijcoe.2026.558002.1204

Abstract

This research investigates the effects of duct inlet length (L) and the distance between the Rotor and stator on the hydrodynamic performance of a pre-swirl pump jet. For this aim, five geometries with different duct inlet lengths L equal to (0 ~ 0.1DRotor) were generated using a direct design method. Furthermore, these geometries were experimentally tested in a cavitation tunnel and validated through numerical simulations using ANSYS Fluent software; it can be concluded that there is good agreement between the experimental and numerical results. Additionally, uncertainty analysis was performed to control the accuracy of the experimental data. The results indicate that an increase in the duct inlet's length and closing the stator to the Rotor leads to more accurate guidance of exiting flow lines of the stator towards the rotor blades. This, in turn, increases the rotor lift coefficient and generates a greater pressure difference across the Rotor, resulting in an increase in the total propulsor thrust coefficient and a subsequent rise in open-water efficiency at specific advance ratios. The maximum relative uncertainty for open-water efficiency was 1.79%. Among the tested configurations, the maximum open-water efficiency of 62.15% was observed for the L=0.1DR case at an advance ratio of 1.1. The minimum efficiency at the same advance ratio was 59.12% for the L=0DR case. Further analysis of the simulation results shows that the L=0.1DR case is superior to other configurations due to having the highest open-water efficiency (approximately 5% higher than the minimum value).

Keywords

pumpjet

Stator and rotor distance

Rotor diameter

Open-water efficiency

Thrust coefficient

Subjects