TY - JOUR ID - 34976 TI - A NUMERICAL STUDY ON STEAM EJECTOR OPTIMUM PERFORMANCE JO - The International Conference on Applied Mechanics and Mechanical Engineering JA - AMME LA - en SN - 2636-4352 AU - Ghonim, T. A. AU - Farag, M. S. AU - Hegazy, A. S. AD - Lecture, Dept. of Mech. Power Engineering, Faculty of Engineering, Menoufia University, Shebin El-Kom, Egypt. AD - Professor, Dept. of Mech. Power Engineering, Faculty of Engineering, Menoufia University, Shebin El-Kom, Egypt. Y1 - 2018 PY - 2018 VL - 18 IS - 18th International Conference on Applied Mechanics and Mechanical Engineering. SP - 1 EP - 17 KW - Steam Ejector KW - Mass Ratio KW - Ejector Efficiency KW - CFD KW - Geometrical parameters DO - 10.21608/amme.2018.34976 N2 - ABSTRACTThe present paper introduces a numerical study on the optimum performance ofsteam ejector at constant pressure ratio. Both the suction and motive fluids areassumed to be dry steam. As a result of the low pressure created at the exit of thesupersonic motive steam nozzle, a suction steam is entrained to be mixed with themotive steam where both flows continue flowing towards the ejector exit. Mass ratioof suction to motive flows is a vital parameter to enhance the ejector performance.The objective of the present study is to maximize the steam ejector efficiency byoptimizing the ejector mass ratio. The effect of three different geometrical parameterson ejector mass ratio and its efficiency is investigated at constant operatingconditions. These parameters are the ejector convergent section angle, the length ofthe constant area mixing chamber and the ejector divergent section angle. Thetheoretical model is formulated based on single phase (superheated steam), twodimensionaland compressible flow using the finite volume solver, FLUENT 6.3. Inaddition, steady, axisymmetric horizontal ejector is considered. The realizablek −e model is used to model turbulence in the present simulation. The proposednumerical model is validated with the available experiments in literature. The resultsshowed that the ejector wall static pressure distributions were greatly affected by thethree investigated geometrical parameters. Furthermore, at constant operatingconditions (motive, suction and back pressures) separation in the ejector divergentsection started to take place at 10o at b =4.8o. In order to avoid separation, theejector divergent section angle must be selected carefully together with the operatingconditions. The ejector mass ratio and efficiency increased with increasing thepreviously stated three geometrical parameters to gain there upper limit values,subsequent to that, the efficiency and mass ratio decreased with increasing thesegeometrical parameters. Moreover, it is finally concluded that there are certainoptimum ejector convergent, divergent angles and the length of the constant areamixing chamber in order to optimize the ejector mass ratio and consequently itsefficiency at given constant operating condition. UR - https://amme.journals.ekb.eg/article_34976.html L1 - https://amme.journals.ekb.eg/article_34976_00aca902c1adb789233cb126101b2d6d.pdf ER -