Hostname: page-component-cb9f654ff-fg9bn Total loading time: 0 Render date: 2025-08-30T08:31:27.273Z Has data issue: false hasContentIssue false
  • English
  • Français

Turbulent mixing in a free jet issuing froma low aspect ratio contoured rectangularnozzle

Published online by Cambridge University Press:  04 July 2016

W. R. Quinn
W. R. Quinn*
Affiliation:
Department of EngineeringSt Francis Xavier UniversityNova Scotia, Canada
Get access Rights & Permissions [Opens in a new window]

Abstract

The flow field of a turbulent free jet issuing from acontoured rectangular nozzle of aspect ratio 2 hasbeen studied experimentally, using hot-wireanemometry. The study was undertaken to gain someunderstanding of the mixing process within the jet.Results of the measured and derived mean flow andturbulence quantities are presented. The threecomponents of the mean velocity vector, the threeReynolds normal stresses, the two Reynolds primaryshear stresses, and the flatness factor of thestreamwise fluctuating velocity were measured. Massentrainment, turbulence kinetic energy, and theintermittency factor were derived from the meanstreamwise velocity data, the Reynolds normal stressdata, and the flatness factor data, respectively.The derived results and the Reynolds primary shearstress data indicate enhanced near-field mixing ofthe present rectangular jet compared to a roundturbulent free jet. The mean streamwise velocityfield changes from a rectangular to an oval and thento an approximately circular shape at about twentyequivalent nozzle diameters downstream of the nozzleexit plane.

Information

Type
Research Article
Information
The Aeronautical Journal , Volume 99 , Issue 988 , October 1995 , pp. 337 - 342
Copyright
Copyright © Royal Aeronautical Society 1995 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Article purchase

Temporarily unavailable

References

1. Quinn, W.R. Turbulent free jet flows issuing from sharp-edged rectangular slots: the influence of slot aspect ratio, Experimental Thermal Fluid Science, 1992, 5, (2), pp 203–215.Google Scholar
2. Quinn, W.R. Development of a large-aspect-ratio rectangular turbulent free jet, AIAA J, 1994, 32, (3), pp 547–554.Google Scholar
3. Marsters, G.F. The effects of upstream nozzle shaping on incom pressible turbulent flows from rectangular nozzles, Transactions of the Canadian Society for Mechanical Engineering, 1979, 5, (4), pp 197–203.Google Scholar
4. Krothapalli, A., Baganoff, D. and Karamcheti, K. On the mixing of a rectangular jet, J Fluid Mech, 1981, 107, pp 201–220.Google Scholar
5. Tsuchiya, Y., Horikoshi, C. and Sato, T. On the spread of rectangular jets, Experiments in Fluids, 1986, 4, (4), pp 197–204.Google Scholar
6. Morrison, G.L. and Swan, D.H. Three-dimensional flow field measurements of a 4:1 aspect ratio subsonic jet, AIAA Paper No 89-1092.Google Scholar
7. Bradshaw, P. An Introduction to Turbulence and Its Measurement, Pergamon, Oxford, England, 1975.Google Scholar
8. Bearman, P.W. Corrections for the effect of ambient temperature drift on hot-wire measurements in incompressible flow, DISA Infor mation, 1971,11, (11), pp 25–30.Google Scholar
9. Bell, J.H. and Mehta, R.D. Three-dimensional structure of plane mixing layers, JIAA Report TR-90, Dept of Aeronautics and Astro nautics, Stanford University, 1989.Google Scholar
10. Panchapakesan, N.R., and Lumley, J.L. Turbulence measurements in axisymmetric jets of air and helium. Part 1: Air Jet, J Fluid Mech, 1993, 246, pp 197–223.Google Scholar
11. Bradshaw, P. Turbulent secondary flows, Annual Review of Fluid Mechanics, 1987, 19, pp 53–74.Google Scholar
12. Abramovich, G.N. On the deformation of the rectangular turbulent jet cross-section, Int J Heat Mass Trans, 1982, 25, (18), pp 1885–1894.Google Scholar
13. Ho, C.-M. and Gutmark, E. Vortex induction and mass entrainment in a small-aspect-ratio elliptic jet, J Fluid Mech, 1987, 179, pp 383–405.Google Scholar
14. Hill, B.J. Measurement of local entrainment rate in the initial region of axisymmetric turbulent air jets, J Fluid Mech, 1971, 51, pp 773–779.Google Scholar
15. Boguslawski, L. and Popiel, C.O. Flow structure of the free round turbulent jet in the initial region, J Fluid Mech, 1979, 90, Pt III, pp 531–539.Google Scholar