Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-25T02:03:06.041Z Has data issue: false hasContentIssue false
  • English
  • Français

Aspect ratio effect on elliptical sonic jet mixing

Published online by Cambridge University Press:  07 June 2016

V. Chauhan ,
S.M. Aravindh Kumar  and
E. Rathakrishnan
V. Chauhan*
Affiliation:
Department of Aerospace Engineering, Indian Institute of Technology, Kanpur, India
S.M. Aravindh Kumar*
Affiliation:
Department of Aerospace Engineering, Indian Institute of Technology, Kanpur, India
E. Rathakrishnan*
Affiliation:
Department of Aerospace Engineering, Indian Institute of Technology, Kanpur, India
*
vinayc@iitk.ac.in
aravinds@iitk.ac.in
erath@iitk.ac.in
Get access Rights & Permissions [Opens in a new window]

Abstract

The effects of aspect ratio on elliptical sonic jet decay at different levels of under-expansion has been studied experimentally. Elliptical sonic jets from orifices of same area with aspect ratios (AR) 2, 4 and 6 at nozzle pressure ratios 2 to 5 in steps of 1 have also been studied. A circular jet from an orifice with an area equal to that of elliptical orifice was also studied for comparison. Jet centreline pressure decay, spread and waves present in the jet core were analysed. The results show that the mixing of the elliptical jet is superior to the circular jet, at all the nozzle pressure ratios of the present study. Also, the aspect ratio of the elliptical orifice has a strong influence on the jet mixing. Elliptical jets of aspect ratio 4 and 6 experience a significantly higher mixing than the aspect ratio 2 jet, till the under-expansion level corresponding to Mach disk formation. For higher under-expansion levels, the mixing of AR 4 and 6 jets become inferior to that of the AR 2 jet.

Keywords

elliptical jetaxis-switchingcore lengthunder-expansionshock cell
Type
Research Article
Information
The Aeronautical Journal , Volume 120 , Issue 1230 , August 2016 , pp. 1197 - 1214
Copyright
Copyright © Royal Aeronautical Society 2016 

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

REFERENCES

1. Rathakrishnan, E. Applied Gas Dynamics, John Wiley, NJ, 2010.Google Scholar
2. Hatanaka, K. and Saito, T. Influence of nozzle geometry on underexpanded axisymmetric free jet characteristics, Shock Waves, 2012, 22, pp 427–434.CrossRefGoogle Scholar
3. Dosanjh, D.S. and Sheeran, W.J. Observations on jet flows from a two-dimensional underexpanded sonic nozzle, AIAA J, 1968, 6, (3), pp 540–542.CrossRefGoogle Scholar
4. Grist, S., Sherman, P.M. and Glass, D.R. Study of the highly underexpanded sonic jet, AIAA J, 1966, 4, (1), pp 68–71.Google Scholar
5. Davidor, W. and Penner, S.S. Shock standoff distances and Mach-disk diameters in underexpanded sonic jets, AIAA J, 1971, 9, (8), pp 1651–1653.Google Scholar
6. Grinstein, F.F., Gutmark, E. and Parr, T. Near field dynamics of subsonic free square jets:a computational and experimental study, Physics of Fluids, 1995, 7, (6), pp 1483–1497.Google Scholar
7. Gutmark, E., Schadow, K.C. and Wilson, K.J. Subsonic and supersonic combustion using noncircular injectors, J Propulsion, 1991, 7, (2), pp 240–249.Google Scholar
8. Miller, R.S., Madnia, C.K. and Givi, P. Numerical simulation of non-circular jets, Computer & Fluids, 1995, 24, (1), pp 1–25.CrossRefGoogle Scholar
9. Koshigoe, S., Gutmark, E. and Schadow, K.C. Initial development of noncircular jets leading to axis-switching, AIAA J, 1989, 27, (4), pp 411–419.Google Scholar
10. Schadow, K.C., Gutmark, E., Koshigoe, S. and Wilson, K.J. Combustion-related shear-flow dynamics in elliptical supersonic jets, AIAA J, 1989, 27, (10), pp 1347–1353.CrossRefGoogle Scholar
11. Quinn, W.R. Experimental study of the near field and transition region of a free jet issuing from a sharp-edged elliptical orifice plate, European Journal of Mechanics B / Fluids, 2007, 26, pp 583–614.Google Scholar
12. Mitchell, D.M., Honnery, D.R. and Soria, J. Near-field structure of underexpanded elliptical jets, Exp Fluids, 2013, 54, p 1578.Google Scholar
13. Yoon, J.H. and Lee, S.J. Investigation of the near-field structure of an elliptical jet using stereoscopic particle image velocimetry, Measurement Science & Technology, 2003, 14, pp 2034–2046.CrossRefGoogle Scholar
14. Hussain, F. and Husain, H.S. Elliptical jets, Part 1, Characteristics of unexcited and excited jets. Journal of Fluid Mechanics, 1989, 208, pp 257–320.Google Scholar
15. Quinn, W.R. On mixing in an elliptical turbulent free jet, Physics of Fluids, 1989, 1, (10), pp 1716–1722.Google Scholar
16. Ho, C.M. and Gutmark, E. Vortex induction and mass entrainment in a small aspect-ratio elliptical jet, J Fluid Mechanics, 1987, 179, pp 383–405.Google Scholar
17. Verma, S.B. and Rathakrishnan, E. Flow and acoustic properties of underexpanded elliptic-slot jets, J Propulsion and Power, 2001, 17, pp 49–57.Google Scholar
18. Verma, S.B. and Rathakrishnan, E. Effect of Mach number on the acoustic field of 2:1 elliptic-slot jet, Aeronautical J, 2001, 105, pp 9–16.Google Scholar
19. Clement, S., Murugan, K.N. and Rathakrishnan, E. Superiority of elliptical jets, J Institution of Engineers (India), May 2005, 86, pp 1–7.Google Scholar
20. Rathakrishnan, E. Experimental studies on the limiting tab, AIAA J, 2009, 47, (10), pp 2475–2485.Google Scholar
21. Katanoda, H., Miyazato, Y., Masuda, M. and Matsuo, K. Pitot pressures of correctly-expanded and underexpanded free jets from axisymmetric supersonic nozzles, Shock Waves, 10, (2), 2000, pp 95–101.Google Scholar
22. Rathakrishnan, E. Instrumentation, Measurements, and Experiments in Fluids, CRC Press, Boca Raton, Florida, USA, 2007.Google Scholar