art%3A10.1007%2Fs00348-015-2090-8.pdf (4.89 MB)
Download file

Measurements in the annular shear layer of high subsonic and under-expanded round jets

Download (4.89 MB)
journal contribution
posted on 16.06.2016, 13:31 by T. Feng, Jim McGuirk
An experimental study has been undertaken to document compressibility effects in the annular shear layers of axisymmetric jets. Comparison is made of the measured flow development with the well-documented influence of compressibility in planar mixing layers. High Reynolds number (~106) and high Mach number jets issuing from a convergent nozzle at nozzle pressure ratios (NPRs) from 1.28 to 3.0 were measured using laser Doppler anemometry instrumentation. Detailed radial profile data are reported, particularly within the potential core region, for mean velocity, turbulence rms, and turbulence shear stress. For supercritical NPRs the presence of the pressure waves in the inviscid shock cell region as the jet expanded back to ambient pressure was found to exert a noticeable effect on shear layer location, causing this to shift radially outwards at high supercritical NPR conditions. After a boundary layer to free shear layer transition zone, the turbulence development displayed a short region of similarity before adjustment to near-field merged jet behaviour. Peak turbulence rms reduction due to compressibility was similar to that observed in planar layers with radial rms suppression much stronger than axial. Comparison of the compressibility-modified annular shear layer growth rate with planar shear layer data on the basis of the convective Mach number (M C) showed notable differences; in the annular shear layer, compressibility effects began at lower M C and displayed a stronger reduction in growth. For high Mach number aerospace propulsion applications involving round jets, the current measurements represent a new data set for the calibration/validation of compressibility-affected turbulence models.

Funding

This work was funded by EPSRC [Grant No. GR/S27467/01] via the MSTTAR DARPS consortium.

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Aeronautical and Automotive Engineering

Published in

EXPERIMENTS IN FLUIDS

Volume

57

Issue

1

Citation

FENG, T. and MCGUIRK, J., 2016. Measurements in the annular shear layer of high subsonic and under-expanded round jets. Experiments in Fluids, 57 (1), article 7.

Publisher

Springer / © The Authors

Version

VoR (Version of Record)

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution 4.0 International (CC BY 4.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/ by/4.0/

Publication date

2015-12-15

Notes

This is an open access article published by Springer and distributed under the terms on the Creative Commons Attribution Licence, CC BY 4.0 (http://creativecommons. org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

ISSN

0723-4864

Language

en

Usage metrics

Keywords

Licence

Exports