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Control of a supersonic elliptical jet

Published online by Cambridge University Press:  08 November 2017

A. Bajpai  and
E. Rathakrishnan
A. Bajpai
Affiliation:
Indian Institute of Technology, Kanpur, India
E. Rathakrishnan*
Affiliation:
Indian Institute of Technology, Kanpur, India
*
[email protected]
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Abstract

Mach 2 jet from a convergent-divergent elliptical nozzle, of aspect ratio 2, has been controlled with limiting flat and arc tabs. The mixing promoting capability of the flat and arc tabs were studied in the presence of different levels of pressure gradient, at the nozzle exit, corresponding to nozzle pressure ratios of 4 to 8, in steps of one. The geometrical blockage of both the tabs is 5% of nozzle exit area. For the flat tab along the minor axis, the waves in the core become weaker and the core length becomes shorter than the uncontrolled jet, at all the NPRs studied. But the flat tab along the major axis promotes mixing only for some NPRs and retards the mixing for the rest of the NPRs studied. At NPR 5, the flat tab along the minor axis causes the largest core length reduction of 86%. For circular arc tab, along the minor axis, the maximum core length reduction is 55% at NPR 6. Arc tab along the major axis protects the core length for the entire range of the nozzle pressure ratios tested and maximum extension in core length is found at NPR 4, which is 40%.

Keywords

JetSupersonicElliptic NozzleLimiting Tab
Type
Research Article
Information
The Aeronautical Journal , Volume 122 , Issue 1247 , January 2018 , pp. 131 - 147
Copyright
Copyright © Royal Aeronautical Society 2017 

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