Characteristics of a co-flowing jet with varying lip thickness and constant velocity ratio
Aircraft Engineering and Aerospace Technology
ISSN: 0002-2667
Article publication date: 16 April 2020
Issue publication date: 28 April 2020
Abstract
Purpose
This study aims to analyze co-flowing jets (CFJs) with constant velocity ratio (VR) and varying primary nozzle lip thickness (LT) to find a critical LT in CFJs below which mixing enhances and beyond which mixing inhibits.
Design/methodology/approach
CFJs were characterized with a constant VR and varying LTs. A single free jet with a diameter equal to that of a primary nozzle of the CFJ was used for characteristic comparison. Numerical simulation is carried out and is validated with the experimental results.
Findings
The results show that within a critical limit, the mixing enhanced with an increase in LT. This was signified by a reduction in potential core length (PCL). Beyond this limit, mixing inhibited leading to the elongation of PCL. This limit was controlled by parameters such as LT and constant VR. A new region termed as influential wake zone is identified.
Practical implications
In this study, the VR is maintained constant and bypass ratio (BR) was varied from low value to very high values. Presently, subsonic commercial turbo fan operates under low to ultra-high BR. Hence the present study becomes vital to the current scenario.
Originality/value
To the best of the authors’ knowledge, this is the first effort to find the critical value of LT for a constant VR for compressible co-flow jets. The CFJs with constant VR and varying LT have not been studied in the past. The present study focuses on finding a critical LT below which mixing enhances and above which mixing inhibits.
Keywords
Acknowledgements
The authors thank Dr K. Vijayaraja, Head, Department of Aeronautical Engineering, KCG College of Technology, for permitting to conduct experiments.
Citation
R., N.S., S., K.B., N., D.R. and K., S.K. (2020), "Characteristics of a co-flowing jet with varying lip thickness and constant velocity ratio", Aircraft Engineering and Aerospace Technology, Vol. 92 No. 4, pp. 633-644. https://doi.org/10.1108/AEAT-05-2019-0104
Publisher
:Emerald Publishing Limited
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