Experimental and numerical study of a Water-Water ejector
Masters of science (MSc) 2025
By
Marwan Adel Kabaly
Supervisors
Prof. Hassan El-Gamal
Mechanical Engineering Department
Faculty of Engineering
Alexandria University
Prof. Elsayed Saber
Mechanical Engineering Department
College of Engineering and Technology
Arab Academy for Science and Technology and Maritime Transport
Mechanical Engineering Department
College of Engineering and Technology
Arab Academy for Science and Technology and Maritime Transport
Abstract
Jet pumps, have garnered significant attention due to their robust, maintenance-free construction and versatility across various industrial applications, including desalination, oil recovery, district heating, and chemical processing. Despite their structural simplicity, optimizing jet pump performance under varying operational and geometrical conditions remains a complex engineering challenge. This study presents a combined experimental and numerical investigation into the performance characteristics of a water–water jet pump system, focusing on flow behavior, efficiency, and pressure dynamics across multiple elevation levels.
A physical jet pump model—comprising a nozzle, mixing chamber, throat, and diffuser—was fabricated and tested using a custom-designed experimental rig equipped with precision instrumentation, including pressure gauges, tachometers, and flow controllers. Concurrently, a three-dimensional Computational Fluid Dynamics (CFD) model was developed in ANSYS FLUENT using a pressure-based solver and SST k-ω turbulence model, with mesh independence analysis ensuring numerical robustness.
The experimental results revealed a nonlinear increase in efficiency with mass flow rate, peaking at approximately 33% at an elevation of 2.5 m. Meanwhile, the pressure ratio decreased with increased flow rate, illustrating the trade-off between efficiency and pressure maintenance. Numerical simulations closely matched these trends, reaching a peak efficiency of around 35%, and exhibited smoother, more stable performance curves. Comparison with previous literature confirmed strong alignment, validating the accuracy of both approaches.
The findings underscore the value of integrating experimental testing with CFD for predictive modeling and design optimization of jet pumps. The insights gained here offer a deeper understanding of internal flow phenomena and provide practical guidance for enhancing jet pump performance in systems where elevation and flow variability are critical.
Published Papers
Kabaly, M., El-Gamal, H., Saber, E., Afify; R., “Experimental and numerical study of a Water-Water ejector”, Journal of Umm Al-Qura University for Engineering and Architecture, published online 10 July 2025, https://doi.org/10.1007/s43995-025-00183-4
