Corrugated Tabs for Supersonic Jet Mixing

Ethirajan Rathakrishnan; Mrinal Kaushik

doi:10.15866/ireme.v8i6.4756

Corrugated Tabs for Supersonic Jet Mixing

Ethirajan Rathakrishnan^(1*), Mrinal Kaushik⁽²⁾

^(*) Corresponding author

Authors' affiliations

DOI: https://doi.org/10.15866/ireme.v8i6.4756

Abstract

The efficacy of introducing mixing promoting small size vortices of mixed size, generated by two plain and corrugated tabs, fixed at diametrically opposite locations at the exit of a Mach 1.73 convergent-divergent nozzle, has been experimentally investigated. The corrugations in the form of semi-circular, triangular and rectangular corrugations, provided along the tabs edges were studied. Their mixing promoting efficiency for the Mach 1.73 jet at overexpanded, correctly expanded and underexpanded states were studied quantitatively as well as qualitatively. The area blockage due to the each tab was kept constant at 2.5% of the nozzle exit area in all the cases. The tab with rectangular corrugations achieves a maximum core length reduction of 98%. Under identical flow condition the semi-circular and triangular corrugations, respectively, caused core length reduction of just 73% and 77%. In addition to reducing the core length these tabs were also found to be better in weakening the waves and shortening the shock cells length as shown through Shadowgraphic flow visualization images.
Copyright © 2014 Praise Worthy Prize - All rights reserved.

Keywords

Supersonic Jet Core; Shock-Cell Length; Jet Mixing; Noise Attenuation; Shadowgraphic Flow Visualization

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