Lip thickness effect on high bypass co-flowing jet mixing
Aircraft Engineering and Aerospace Technology
ISSN: 0002-2667
Article publication date: 20 April 2022
Issue publication date: 5 December 2022
Abstract
Purpose
The purpose of this study is to analyse numerically and experimentally the effects of lip thickness (LT) and bypass ratio on co-flowing nozzle under subsonic and correctly expanded sonic jet decay at different Mach numbers.
Design/methodology/approach
Co-flowing jets from co-flowing nozzles of different LTs, 0.2, 1 and 1.5 Dp (where Dp is the primary nozzle exit diameter = 10 mm), with an annular gap of 10 mm at main jet exit Mach numbers 0.6 have been studied experimentally and the other cases have been performed numerically. The co-flowing jet with 2 mm LT was used for comparison.
Findings
Co-flowing jet axial pitot pressure decay, axial static pressure decay, axial velocity decay, radial velocity decay and streamline velocity contours were analyzed. The results illustrate that the mixing of the co-flowing jet with profound LT is prevalent to the co-flowing jet with 2 mm LT, at all Mach numbers of the current study. Also, the LT of the co-flowing jet has a strong impact on jet mixing. Co-flowing jets with 10 mm and 15 mm LT with a constant co-flow width of 10 mm experience a considerably advanced mixing than co-flowing jets with 2 mm LT and a co-flow width of 10 mm.
Practical implications
The application of bypassed co-flow jet is in turbofan engine operates efficiently in modern civil aircraft.
Originality/value
All subsonic jets are considered correctly expanded with negligible variation in axial static pressure. However, in the present study, static pressure along the centerline varies sinusoidally up to 9% and 12% above and below atmospheric pressure, respectively, for primary jet exit Mach number 1.0. The sinusoidal variation is less for primary jet exit Mach numbers 0.6 and 0.8 in static pressure decay.
Keywords
Acknowledgements
The authors wish to thank Dean (R&D) Prof. Dr E. Balasubramanian, Dean (Industry Relations), Prof. Dr P. Chandrakumar and Dr R. Jaganraj (HoD/Aero) for providing the workstations to carry out the numerical study. The authors thank Dr K. Vijayaraja, Head, Department of Aeronautical Engineering, KCG College of Technology, for permitting to conduct experiments. The authors wish to thank the supporting staffs in the High Speed Jet Lab of KCG College of Technology during the experimental work.
Citation
R., N.S. and V.G., G. (2022), "Lip thickness effect on high bypass co-flowing jet mixing", Aircraft Engineering and Aerospace Technology, Vol. 94 No. 10, pp. 1614-1627. https://doi.org/10.1108/AEAT-02-2021-0050
Publisher
:Emerald Publishing Limited
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