Review of ejector nozzles. Part 2 – Mixers and additional information

• Published in: Avìacìjno-kosmìčna tehnìka ì tehnologìâ no. 4sup1; pp. 92 - 101
• Main Authors: Tsukanov, Ruslan, Yepifanov, Sergiy
• Format: Journal Article
• Language: English
• Published: National Aerospace University «Kharkiv Aviation Institute 27.08.2025
• Subjects: ejector mixing chamber; entrainment ratio; gas-turbine engine; primary nozzle; thrust augmentation; thrust augmenting ejector nozzle
• ISSN: 1727-7337; 2663-2217; 2663-2217
• DOI: 10.32620/aktt.2025.4sup1.12

The subject of this article is ejector nozzles, which are intended for the thrust augmentation of jet engines and their corresponding flow mixers. The goal is to soften the acuteness of contradictions between the required high performance (especially thrust augmentation) and compactness and between the conflicting objectives of achieving a high mixing rate with low total primary flow pressure losses within a short overall length. The tasks to be solved are as follows: revealing ways for thrust augmentation and external drag minimization of ejector nozzles through analysis of turbofan forced lobe mixer investigations, experimental studies of the shape and location of additional air intakes, experimental studies of shapes of afterbodies, and ejector investigations from other fields of engineering. The following methods were used: search of corresponding information sources on the Internet and analysis based on operational experience in the aviation branch. The following results were obtained: in terms of found information sources, the most effective devices for mixing up the primary and the secondary flows within short mixing ducts are forced lobe mixers; their advantages and disadvantages are formulated; and three mechanisms responsible for the mixing process behind the lobe mixers were revealed. A large number of experimental investigations of the characteristics of both the additional air intakes and afterbodies of the fuselages and nacelles were considered. The development of both experimental and theoretical ejector investigations in other engineering branches was analyzed. Conclusions. The scientific novelty of the results obtained is as follows: 1) information from numerous sources of literature that characterizes lobe mixers as devices for improving the ejector nozzle efficiency, and development of these mixer study by both theoretical and experimental methods were collected in the review article; 2) recommendations as for selection the shape and location of additional air intakes and afterbodies were revealed; 3) very limited applicability of the ejector models, developed in other fields of engineering, for turbojet engine thrust augmentation was stated. Thus, the development of a design methodology for thrust-augmenting ejector nozzles for micro-turbojets has been revealed. The goal and challenges of the following research are outlined.