Hostname: page-component-cc8bf7c57-j4qg9 Total loading time: 0 Render date: 2024-12-11T22:56:28.988Z Has data issue: false hasContentIssue false
  • English
  • Français

Study of jets from rectangular nozzles with square grooves

Published online by Cambridge University Press:  27 January 2016

P. Arun Kumar ,
S. B. Verma  and
S. Elangovan
S. B. Verma
Affiliation:
Experimental Aerodynamics Division, National Aerospace Laboratories-CSIR, Bangalore, India
S. Elangovan
Affiliation:
Experimental Aerodynamics Division, National Aerospace Laboratories-CSIR, Bangalore, India
Get access Rights & Permissions [Opens in a new window]

Abstract

An experimental study has been carried out to understand jet flow development from plain and grooved rectangular nozzles of aspect ratio 2:1 using two-component hotwire anemometry. Grooves of square configuration (side 4mm) and length 5mm were introduced in the (i) minor-axis, (ii) major-axis and, (iii) in both minor- and major-axes directions. The equivalent diameter of the plain rectangular nozzle is 37·5mm. Studies were carried out for a nominal jet exit velocity of 20ms−1 and for Reynolds number based on equivalent diameter of 54,000. The introduction of grooves in either plane does not show any influence on the potential-core length but results in faster jet-decay thereafter. It is observed that the grooves when introduced in minor-axis direction inhibit the jet growth in that plane while promoting the jet growth along major-axis plane and hence, delays the phenomena of axis-switching. However when introduced in major-axis direction, the grooves promote jet growth along major-axis plane while inhibiting jet-growth in minor-axis plane. Cross-sectional contours of mean-velocity suggest that the grooves modify the process of overall jet development significantly in the plane in which they are introduced relative to the plain jet and hence, significantly affect the axis-switching location in each case.

Type
Research Article
Information
The Aeronautical Journal , Volume 115 , Issue 1165 , March 2011 , pp. 187 - 196
Copyright
Copyright © Royal Aeronautical Society 2011 

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.)

References

1. Krothapalli, A., Baganoff, D. and Karamcheti, K. On the mixing of a rectangular jet, J Fluid Mechanics, 1981, 107, pp 201–220.Google Scholar
2. Hsia, Y., Krothapalli, A., Baganoff, D. and Karamcheti, K. Effects of Mach number on the development of a subsonic rectangular jet, AIAA J, 1982, 21, (2), pp 176–177.Google Scholar
3. Gutmark, E.J. and Grinstein, F.F. Flow control with non-circular jets, Annual Review of Fluid Mechanics, 1999, 31, pp 239–272.Google Scholar
4. Hussain, H.S. and Husain, A.K.M.F. Elliptic jets part I: characteristics of unexcited and excited jets, J Fluid Mechanics, 1989, 208, pp 257–319.Google Scholar
5. Ho, C.M. and Gutmark, E.J. Vortex induction and mass entrainment in a small-aspect ratio elliptic jet, J Fluid Mechanics, 1987, 179, pp 383–405.Google Scholar
6. Quinn, W.R. On mixing in an elliptic turbulent free jet, Physics of Fluids, 1989, 10, pp 1716–1721.Google Scholar
7. Tsuchiya, Y., Horikoshi, C. and Sato, T. On the spread of rectangular jets, Experiments in Fluids, 1986, 4, pp 197–204.Google Scholar
8. Marsters, G.F. Spanwise velocity distributions in jet from rectangular slots, AIAA J, 19, (2), pp 148–152.Google Scholar
9. Mi, J., Deo, R.C., and Nathan, J. Characterization of turbulent jets from high-aspect-ratio rectangular nozzle, 2005, Physics of Fluids, 17, pp 68102–1-68102-4.Google Scholar
10. Elangovan, S. and Rathakrishnan, E. Studies on high speed jets from nozzles with internal grooves, Aeronaut J, 2004, 108, pp 43–50.Google Scholar
11. Vishnu, J. and Rathakrishnan, E. Acoustic characteristics of supersonic jets from grooved nozzles, J Propulsion and Power, 2004, 20, (3), pp 520–526.Google Scholar
12. Srinivasan, K. and Rathakrishnan, E. Studies on polygonal slot jets, AIAA J, 1985, 38, (10).Google Scholar
13. Bradbury, L.J.S. and Khadem, A.H. The distortion of a jet by tabs, J Fluid Mech, 1975, 70, pp 801–813.Google Scholar
14. Chua, L.P., Yu, S.C.M. and Wang, X.K. Flow visualization and measurements of a square jet with mixing tabs, Exper Thermal Fluid Sci, 2003, 27, pp 731–744.Google Scholar
15. Ahuja, K.K. and Brown, W.H. Shear flow control by mechanical tabs, AIAA paper 89-0094.Google Scholar
16. Zaman, K.B.M.Q., Reeder, M.F. and Samimy, M. Control of an axisymmetric jet using vortex generators, Phys Fluids, 1994, 6, (2), pp 778–793.Google Scholar
17. Verma, S.B., Sudhakar, S. and Venkatakrishnana, L. Experimental study on a jet issuing from an elliptic nozzle with cylindrical tabs, J Turbulence, 2010, 11, 20, pp 1–24 Google Scholar