Engineering Transactions, 69, 3, pp. 257–269, 2021

A Computational Analysis of Different Geometric Ratios at the Input of a Secondary Fluid that Affects the Efficiency of a Subsonic Air-Air Ejector

Institución Universitaria Pascual Bravo

Instituto Tecnológico Metropolitano

Universidad de Antioquia

Instituto Tecnológico Metropolitano

For this study, the computational fluid dynamics (CFD) technique was used to investigate the combined effects of different geometric parameter relationships; inclination angle variation of the secondary fluid inlet, different lengths of the mixing chamber, and different separation values between the nozzle outlet and the input of the mixing chamber, in an air-air ejector used in a subsonic regime. As a working fluid, the air was used as an ideal gas and its viscosity was expressed as a constant both in the primary and secondary fluids. The renormalization group (RNG) κ-ε turbulence model was used to predict more accurately the way the pressure recovers along the ejector and suitability/applicability to for recirculation flows. It was found in the numerical results that there is an optimal value of the inclination angle for the secondary fluid inlet, the length of the mixing chamber and the separation between the nozzle outlet and the mixing chamber inlet, where the ejector obtains its maximum mass flow ratio. In addition, it was found that the efficiency of the air-air ejector is related to the inclination angle of the secondary fluid inlet.

Keywords: ejector; geometric parameters; subsonic flow; CFD; Ansys Fluent
Full Text: PDF
Copyright © The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0).


Chou S.K., Experimental studies on an air-air jet exhaust pump, ASHRAE Tranctions (United States), 92(2A): 497–506, 1986.

Li F. et al, Experimental determination of the water vapor effect on subsonic ejector for proton exchange membrane fuel cell (PEMFC), International Journal of Hydrogen Energy, 42(50): 29966–29970, 2017, doi: 10.1016/j.ijhydene.2017.06.226.

Chunnanond K., Aphornratana S., Ejectors: applications in refrigeration technology, Renewable and Sustainable Energy Reviews, 8(2): 129–155, 2004, doi: 10.1016/j.rser.2003.10.001.

Cępa P., Lisowski E., Application of pneumatic suction cup as a positioning element for thin metal sheets in technological processes, Technical Transactions; Mechanics, 2013(1-M (5)): 5–12, 2013, doi: 10.4467/2353737XCT.14.001.1927.

Meakhail T.A., Zien Y., Elsallak M., AbdelHady S., Experimental study of the effect of some geometric variables and number of nozzles on the performance of a subsonic air-air ejector, Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 222(8): 809–818, 2008, doi: 10.1243/09576509JPE618.

Florean F.G., Petcu A.C., Porumbel I., Dediu G., PIV measurements in low noise optimized air jet pump demonstrators, International Journal of Energy, 10: 33–43, 2016.

Aissa W.A., Performance analysis of cylindrical type air ejector, JES. Journal of Engineering Sciences, 34(3): 733–745, 2006, doi: 10.21608/jesaun.2006.110609.

Manzano J. Palau C.V, de Azevedo Benito M., do Bomfim Guilherme V., Vasconcelos D.V., Geometry and head loss in Venturi injectors through computational fluid dynamics, Engenharia Agrícola, 36(3): 482–491, 2016, doi: 10.1590/1809-4430-Eng.Agric.v36n3p482-491/2016.

Lisowski E., Momeni H., CFD modeling of a jet pump with circumferential nozzles for large flow rates, Archives of Foundry Engineering, 10(3): 69–72, 2010.

Liu Y., Costigan G., CFD simulations of swirling effects on the performance of the supersonic nozzle for micro-particle delivery, [in:] Proceedings of the 5th WSEAS International Conference on Applied Computer Science, Hangzhou, China, April 16–18, 2006, pp. 584–589, 2006.

Genc O., Timurkutluk B., Toros S., Performance evaluation of ejector with different secondary flow directions and geometric properties for solid oxide fuel cell applications, Journal of Power Sources, 421: 76–90, 2019, doi: 10.1016/J.JPOWSOUR.2019.03.010.

Yakhot V., Orszag S.A., Thangam S., Gatski T.B., Speziale C.G., Development of turbulence models for shear flows by a double expansion technique, Physics of Fluids A: Fluid Dynamics, 4(7): 1510–1520, 1992, doi: 10.1063/1.858424.

Bartosiewicz Y., Aidoun Z., Desevaux P., Mercadier Y., CFD-experiments integration in the evaluation of six turbulence models for supersonic ejectors modeling, [in:] Proceedings of Integrating CFD and Experiments Conference, Glasgow, UK, 2003.

Taherian M., Saedodin S., Valipour M.S., Numerical simulation of subsonic jet ejector, Journal of Modeling in Engineering, 14(45): 63–78, 2016, doi: 10.22075/jme.2017.1763.

Winoto S.H., Li H., Shah D.A., Efficiency of jet pumps, Journal of Hydraulic Engineering, 126(2): 150–156, 2000, doi: 10.1061/(ASCE)0733-9429(2000)126:2(150).

Chunnanond K., Aphornratana S., An experimental investigation of a steam ejector refrigerator: the analysis of the pressure profile along the ejector, Applied Thermal Engineering, 24(2–3): 311–322, 2004, doi: 10.1016/j.applthermaleng.2003.07.003.

DOI: 10.24423/EngTrans.1265.20210826