Open Access

ARTICLE

Optimization Analysis of the Mixing Chamber and Diffuser of Ejector Based on Fano Flow Model

by Lixing Zheng^1,*, Weibo Wang², Yiyan Zhang¹, Lingmei Wang³, Wei Lu²

1 School of Electric Power, Civil Engineering and Architecture, Shanxi University, Taiyuan, 030006, China
2 School of Mechanical Engineering, Guangxi University, Nanning, 530004, China
3 Wind Turbine Monitoring and Diagnosis, NTRC of Shanxi Province, Taiyuan, 030006, China

* Corresponding Author: Lixing Zheng. Email:

(This article belongs to the Special Issue: Recent Advance of the Isogeometric Boundary Element Method and its Applications)

Computer Modeling in Engineering & Sciences 2022, 133(1), 153-170. https://doi.org/10.32604/cmes.2022.021235

Received 03 January 2022; Accepted 09 February 2022; Issue published 18 July 2022

Abstract

An improved model to calculate the length of the mixing chamber of the ejector was proposed on the basis of the Fano flow model, and a method to optimize the structures of the mixing chamber and diffuser of the ejector was put forward. The accuracy of the model was verified by comparing the theoretical results calculated using the model to experimental data reported in literature. Variations in the length of the mixing chamber L_m and length of the diffuser L_d with respect to variations in the outlet temperature of the ejector T_c, outlet pressure of the ejector p_c, and the expansion ratio of the pressure of the primary flow to that of the secondary flow p_g/p_e were investigated. Moreover, variations in L_m and L_d with respect to variations in the ratio of the diameter of the throat of the motive nozzle to the diameter of the mixing chamber d_g0/d_c3 and ratio of the outlet diameter of the diffuser to the diameter of the mixing chamber d_c/d_c3 were investigated. The distribution of flow fields in the ejector was simulated. Increasing L_m and d_c3 reduced T_c and p_c. Moreover, reducing p_g/p_e or d_g0/d_c3 reduced T_c and p_c. The length of the mixed section L_m2, which was determined on the basis of the Fano flow model, increased as p_g increased and decreased as d_c3 increased. The mixing length L_m1, which was considered the primary flow expansion, showed the opposite trend with that of L_m2. Moreover, L_d increased as p_g/p_e and d_c/d_c3 increased. When the value of d_c was 1.8 to 2.0 times as high as that of d_c3, the semi-cone angle of the diffuser ranged between 6° and 12°. At a constant d_c/d_c3, decreasing T_c and p_c increased L_d.

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Keywords

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