Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-22T10:12:43.499Z Has data issue: false hasContentIssue false
  • English
  • Français

Experimental study on the flow and noise characteristics of underexpanded notched slot jets

Published online by Cambridge University Press:  04 July 2016

S. B. Verma  and
E. Rathakrishnan
S. B. Verma
Affiliation:
Department of Aerospace Engineering, Indian Institute of Technology Kanpur, India
E. Rathakrishnan
Affiliation:
Department of Aerospace Engineering, Indian Institute of Technology Kanpur, India
Get access Rights & Permissions [Opens in a new window]

Abstract

An experimental investigation has been carried out to study the effect of notches on the flow and noise characteristics of 2:1 elliptic-slot jets. The effect of variation in notch geometry is also investigated. The presence of the notch is found to provide low-velocity regions in the notched-minor-axis plane thereby intensifying the jet growth along that plane. The interaction of these low-velocity regions with the mean flow results in shorter core-lengths. At under-expansion, the shock-cell lengths are weakened considerably in notched jets resulting in significant reductions in the overall jet noise level. Azimuthal directivity of elliptic jets indicate higher noise intensity radiated along major-axis ends relative to minor-axis sides. Notches seem to circumferentially modify the noise emission characteristics and significantly bring down the noise levels along major-axis-unnotched plane. Polar directivity indicates reduction in both shock noise and jet mixing noise in the forward quadrant.

Type
Research Article
Information
The Aeronautical Journal , Volume 105 , Issue 1047 , April 2001 , pp. 267 - 276
Copyright
Copyright © Royal Aeronautical Society 2002 

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. Hussain, A.K.M.F. and Hussain, H.S. Elliptic jets part I: Characteristics of excited and unexcited jets, J Fluid Mech, 1989, 208, pp 257–320.Google Scholar
2. Gutmark, E. and Schadow, K.C. Selective flow control in triangular jets, Experiments in Fluids, 1988, 6, pp 129–135.Google Scholar
3. Steiger, M.H., Sforza, P.M. and Trentacoste, N. Studies in three-dimensional viscous jets, AIAA J, 1966, 4, (5), pp 800–806.Google Scholar
4. Sfier, A.A. Investigation of three-dimensional turbulent rectangular jets,AIAA J, 1979, 17, (10), pp 1055–1060.Google Scholar
5. Marster, G.F. and Fotheringham, J. The influence of aspect-ratio on incompressible, turbulent flows from rectangular slots, Aeronaut Q,1980, 31, (4), pp. 285–305.Google Scholar
6. Marster, G.F. Spanwise velocity distributions in jets from rectangular slots, AIAA J, 1981, 19, (2) pp 148–152.Google Scholar
7. Quinn, W.R. On mixing in an elliptic turbulent free jet, Physics of Fluids (A), 1989, 1,(10), pp 1716–1721.Google Scholar
8. Gutmark, E., Schadow, K.C., Koshigoe, S. and Wilson, K.J. Combustion related shear flow dynamics in elliptic supersonic jets, AIAA J, 1989,27,(10), pp 1347–1353.Google Scholar
9. Bagdanoff, D., Krothapalli, A. and Karamcheti., K. On the mixing of a rectangular jet, J Fluid Mech, 1981, 107, pp 201–220.Google Scholar
10. Gutmark, E. and Ho, C.M. Vortex induction and mass entrainment in a small aspect-ratio elliptic jet, J Fluid Mech, 1987, 179, pp 383–405.Google Scholar
11. Trentacoste, N. and Sforza, M.P. Further experimental results for three-dimensional jets, AIAA J, 1967, 5, (5), pp 885–891.Google Scholar
12. Quinn, W.R. Experimental and numerical study of a turbulent free square jet, Physics of Fluids, 1988, 31, (5), pp 1017–1025.Google Scholar
13. Dhanak, M.R. and Debernardinis, B. The evolution of an elliptic vortex ring, J Fluid Mech, 1981,109, pp 189–216.Google Scholar
14. Gutmark, E., Schadow, K.C, Koshigoe, S. and Tubis, A. Wave structures in jets of arbitrary shape, part III. Triangular jets, Physics of Fluids, 1988, 31, (6), pp 1410–1419.Google Scholar
15. Schadow, K.C. Gutmark, E. and Wilson, K.J. Subsonic and supersonic combustion using non-circular injectors, J Propulsion and Power,1991,7, (2), pp 240–249.Google Scholar
16. Schadow, K.C, Parr, T.P, Hanson-Parr, D.M., Wilson, K.J. and G, E. Non-circular jets in combustion systems, Experiments in Fluids, 1989,7, pp 248–258.Google Scholar
17. Gutmark, E. and Schadow, K.C. Flow characteristics of orifice and tapered jets, Physics of Fluids, 1987, 30, (11), pp 3448–3454.Google Scholar
18. Wlezien, R.W. and Kibens, K. Influence of nozzle asymmetry on supersonic jets, AIAA J, 1988, 26, (1) pp 27–33, 1988.Google Scholar
19. Powell, A. On the mechanism of choked jet noise, Proc of Physical Society of London, 1953, 66, pp 1039–1057.Google Scholar
20. Glass, D.R. Effects of acoustic feedback in the spread and decay of supersonic jets, AIAA J, 1968,6, (10), pp 1890–1897.Google Scholar
21. Powell, A. On the noise emanating from a two-dimensional jet above the critical pressure, Aeronaut Q, 1953, 4, (2), pp 103–121.Google Scholar
22. Pannu, S.S. and Johanassen, . The structure of jets from notched nozzles, J Fluid Mech, 1976, 74, (3), pp 515–528.Google Scholar
23. McDaniel, J., Krothapalli, A. and Bagdanoff, D. Effect of slotting on the noise of an axisymmetric supersonic jet, AIAA J, 1990, 28, (12), pp 2136–2138.Google Scholar
24. Hussain, A.K.M.F. and Ramjee, V. Effects of axisymmetric contraction shape on incompressible turbulent flows, Trans. ASME, J Fluids Engineering, 1976,98, pp 58–59.Google Scholar
25. Hsia, Y., Bagdanoff, D., Krothapalli, A. and Karamcheti, K. Role of screeching tones in the mixing of an underexpanded rectangular jet, J Sound and Vibration, 1986,106, (11), pp 119–143.Google Scholar
26. Zaman, K.B.M.Q., Samimy, M. and Reeder, M.F.. Effect of tabs on the flow and noise field of a axisymmetric jets, AIAA J, 1993, 31, (4), pp 609–619.Google Scholar
27. Norum, T.D. Screech suppression in supersonic jets, AIAA J, 1983, 21, (2), pp 235–240.Google Scholar
28. Tam, C.K.W. The shock-cell structures and screech frequency of rectangular and nonaxisymmetric supersonic jets, J Sound and Vibration, 1988,121,(1),pp 135–147.Google Scholar
29. Seiner, J.M., Tam, C.K.W. and Yu, J.C. Proposed relationship between broadband shock-associated noise and screech tones, J Sound and Vibration, 1986,110, pp 309–321.Google Scholar
30. Tam, C.K.W. Supersonic jet noise, Annual Review of Fluid Mechanics,1995, 27, pp 17–43.Google Scholar
31. Ahuja, K.K., Tam, C.K.W. and Jones, R.R. Screech tones from free and ducted supersonic jets, AIAA J, 1994, 31, pp 917–922.Google Scholar
32. Tanna, H.K. An experimental study of jet noise, part II: Shock-associated noise, J Sound and Vibration, 1977, 50, pp 429–444.Google Scholar
33. Soderman, P.T., Allen, C.S., Hayes, I.A., Jaeger, S.M., and Krothapalli, A. Flight effects on the far-field noise of a heated supersonic jet, AIAA J, 1997, 35 (6), pp 952–957.Google Scholar
34. Krothapalli, A., Washington, D., King, C.J., and Alvi, F.S. Aeroacoustic properties of a supersonic diamond-shaped jet, AIAA J, 1996, 34, (8), pp 1562–1569.Google Scholar
35. Ho, C.M. and Gutmark, E. Near-field pressure fluctuations of an ellipticjet, AIAA J, 1985, 23, (3), pp 354–358.Google Scholar
36. Schadow, K.C, Wilson, K.J., Gutmark, E. and Bicker, C.J. Nearfield pressure radiation and flow characteristics in low supersonic circular and elliptic jets, Physics of Fluids, 1988, 31, (9), pp 2524–2532.Google Scholar
37. Verma, S.B. and Rathakrishnan, E. Mixing benefit and noise characteristics of notched elliptic-slot jets, AIAA Paper No-98-3258, 34th AIAA/ASME Joint Propulsion conf, Ohio(USA), 13 July 1998.Google Scholar