Design and performance analysis of double-flux supersonic air ejector

Abstract

The main purpose of this study is to design a double-flux supersonic ejector and to evaluate its performance associated with its entrainment ratio by employing Computational Fluid Dynamics methods as well as one-dimensional approach. Since the performance of the ejector systems are strongly dependent on the design, this study concentrates on maximizing the entrainment ratio by varying the corresponding angles and the lengths of the critical segments such as mixing angle, divergence angle, mixing throat length etc., while keeping the operational parameters unaltered. Numerically computed results and the one-dimensional calculations have been compared. It is understood that the proper design is mandatory for achieving efficient entrainment ratios and has prominent effect on the operation of the system. It is found that almost 20% of enhancement on entrainment performance can be obtained solely by modifying the lengths and angles of the ejector’s critical segments without changing the operating conditions. It is also deduced that during these modifications, the complex flow structure through the system should not be disregarded for a thoroughly maximization of the performance and an efficient operation of the ejector. © 2018, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.