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Experiments on the flow and acoustic properties of a moderate-Reynolds-number supersonic jet

Published online by Cambridge University Press:  20 April 2006

T. R. Troutt  and
D. K. Mclaughlin
T. R. Troutt
Affiliation:
Oklahoma State University, Stillwater, Oklahoma, USA Present address: Washington State University, Pullman, Washington.
D. K. Mclaughlin
Affiliation:
Oklahoma State University, Stillwater, Oklahoma, USA Present address: Dynamics Technology, Inc., Torrance, California.
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Abstract

An experimental investigation of the flow and acoustic properties of a moderate-Reynolds-number (Re = 70000), Mach number M = 2·1, axisymmetric jet has been performed. These measurements extended the experimental studies conducted previously in this laboratory to a higher-Reynolds-number regime where the flow and acoustic processes are considerably more complex. In fact, mean-flow and acoustic properties of this jet were determined to be closely comparable to published properties of high-Reynolds-number jets.

The major results of the flow-field measurements demonstrate that the jet shear annulus is unstable over a broad frequency range. The initial growth rates and wavelengths of these instabilities as measured by a hot wire were found to be in reasonable agreement with linear stability theory predictions. Also, in agreement with subsonic-jet results, the potential core of the jet was found to be most responsive to excitation at frequencies near a Strouhal number of S = 0·3. The overall development of organized disturbances around S = 0·2 seems to agree in general with calculations performed using the instability theory originally developed by Morris and Tam.

The acoustic near field was characterized in terms of sound-pressure level and directivity for both natural and excited (pure-tone) jets. In addition, propagation direction and azimuthal character of dominant spectral components were also measured. It was determined that the large-scale flow disturbances radiate noise in a directional pattern centred about 30° from the jet axis. The noise from these disturbances appears from simple ray tracing to be generated primarily near the region of the jet where the coherent fluctuations saturate in amplitude and begin to decay. It was also determined that the large-scale components of the near-field sound are made up predominately of axisymmetric (n = 0) and helical (n = ±1) modes. The dominant noise-generation mechanism appears to be a combination of Mach-wave generation and a process associated with the saturation and disintegration of the large-scale instability. Finally, the further development of a noise-generation model of the instability type appears to hold considerable promise.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 116 , March 1982 , pp. 123 - 156
Copyright
© 1982 Cambridge University Press

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References

Bechert, D. & Pfizenmaier, E. 1975 On the amplification of broad band jet noise by pure tone excitation. J. Sound Vib. 43, 581–587.Google Scholar
Bishop, K. A., Ffowcs Williams, J. E. & Smith, W. 1971 On the noise sources of the unsuppressed high-speed jet. J. Fluid Mech. 50, 21–31.Google Scholar
Browand, F. K. 1966 An experimental investigation of the instability of an incompressible, separated shear layer. J. Fluid Mech. 26, 281–307.Google Scholar
Chan, Y. Y. 1974 Spatial waves in turbulent jets. Phys. Fluids 17, 46–53.Google Scholar
Crighton, D. G. & Gaster, M. 1976 Stability of slowly diverging jet flow. J. Fluid Mech. 77, 397–413.Google Scholar
Crow, S. C. & Champagne, F. H. 1971 Orderly structure in jet turbulence. J. Fluid Mech. 48, 547–591.Google Scholar
Dahan, P. C. & Élias, G. 1976 Source structure pattern in a hot jet by infrared — microphone correlation. A.I.A.A. Paper no. 76–542.Google Scholar
Dosanjh, D. S. & Yu, J. C. 1968 Noise from underexpanded axisymmetric jet flow using radial jet flow impingement. In Proc. A.F.O.S.R.-U.T.I.A.S. Symp. on Aerodynamic Noise, Toronto, pp. 169–188.
Dutt, B. 1977 Role of large scale structures in the noise generation of a turbulent supersonic jet. Ph.D. dissertation, University of Southern California.
Ffowcs Williams, J. E. 1963 The noise from turbulence convected at high speed. Phil. Trans. R. Soc. Lond. A 255, 459–503.Google Scholar
Hussain, A. K. M. F. & Zaman, K. B. M. Q. 1975 Effect of acoustic excitation on the turbulent structure of a circular jet. In Proc. 3rd Interagency Symp. on University Research in Transportation Noise, University of Utah, Salt Lake City.
Johnson, C. B. & Boney, L. R. 1975 A method for calculating a real-gas two-dimensional nozzle contour including the effects of gamma. N.A.S.A. TM X-3243, Langley Research Center, Hampton, Virginia.
Kendall, J. M. 1967 Supersonic boundary layer stability experiments. In Proc. Boundary Layer Trans. Study Group, Meeting, II (Aerospace Rep. TR-0158 (S3816–63)-1).
Kibens, V. 1979 Discrete noise spectrum generated by an acoustically excited jet. A.I.A.A. Paper no. 79-0592.Google Scholar
Ko, C. L., McLaughlin, D. K. & Troutt, T. R. 1978 Supersonic hot-wire fluctuation data analysis with a conduction end-loss correction. J. Phys. E, Sci. Instrum. 11, 488–494.Google Scholar
Lau, J. C., Fisher, M. J. & Fuchs, H. V. 1972 The intrinsic structure of turbulent jets. J. Sound Vib. 22, 379–406.Google Scholar
Laufer, J., Kaplan, R. E. & Chu, W. T. 1973 Acoustic modeling of the jet noise abatement problem. In Proc. Interagency Symp. on University Research in Transportation Noise, Stanford, California.
Laufer, J. & Monkewitz, P. 1980 On turbulent jet flows: a new perspective. A.I.A.A. Paper no. 80-0962.Google Scholar
Laufer, J., Schlinker, R. S. & Kaplan, R. E. 1976 Experiments on supersonic jet noise. A.I.A.A. J. 14, 489–497.Google Scholar
Liu, J. T. C. 1974 Developing large-scale wavelike eddies and the near jet noise field. J. Fluid Mech. 62, 437–464.Google Scholar
Lowson, M. V. & Ollerhead, J. B. 1968 Visualization of noise from cold supersonic jets. J. Acoust. Soc. Am. 44, 624–000.Google Scholar
Maestrello, L. 1976 Two point correlation of sound pressure in the far field of a jet: Experiment. N.A.S.A. TM-72835.
Mclaughlin, D. K., Morrison, G. L. & Troutt, T. R. 1975 Experiments on the instability waves in a supersonic jet and their acoustic radiation. J. Fluid Mech. 69, 73–95.Google Scholar
Mclaughlin, D. K., Morrison, G. L. & Troutt, T. R. 1977 Reynolds number dependence in supersonic jet noise. A.I.A.A. J. 15, 526–532.Google Scholar
Mclaughlin, D. K., Seiner, J. M. & Liu, C. H. 1980 On noise generated by large scale instabilities in supersonic jets. A.I.A.A. Paper no. 80–0964.Google Scholar
Merkine, L. O. & Liu, T. T. C. 1975 On the development of noise-producing larger-scale wavelike eddies in a plane turbulent jet. J. Fluid Mech. 70, 353–368.Google Scholar
Michalke, A. 1969 Sound generation by amplified disturbances in free shear layers. Deutsche Luft- und Raumfahrt Rep. no. 69–90.Google Scholar
Michalke, A. 1971 Instibilität eines kompressiblen runden Freistrahls unter Beruchksichtigung des Einflusses der Strahlgrenzschichtdicke. Z. Flugwiss. 19, 319–328.Google Scholar
Miksad, R. W. 1972 Experiments on the nonlinear states of free-shear-layer transition. J. Fluid Mech. 56, 695–719.Google Scholar
Mollo-Christensen, E. 1960 Some aspects of free shear-layer instability and sound emission. N.A.T.O. Rep. no. 260.Google Scholar
Mollo-Christensen, E. 1967 Jet noise and shear flow instability seen from an experimenter's viewpoint. J. Appl. Mech. 34, 1–7.Google Scholar
Moore, C. J. 1977 The role of shear-layer instability waves in jet exhaust noise. J. Fluid Mech. 80, 321–357.Google Scholar
Morris, P. J. 1977 Flow characteristics of the large scale wavelike structure of a supersonic round jet. J. Sound Vib. 53, 223–244.Google Scholar
Morris, P. J. & Tam, C. K. W. 1977 Near and far field noise from large-scale instabilities of axisymmetric jets. A.I.A.A. Paper no. 77–1351.Google Scholar
Morrison, G. L. 1977 Flow instability and acoustic radiation measurements of low Reynolds number supersonic jets. Ph.D. dissertation, Oklahoma State University, Stillwater, Oklahoma.
Morrison, G. L. & McLaughlin, D. K. 1979 The noise generation by instabilities in low Reynolds number supersonic jets. J. Sound Vib. 65, 177–191.Google Scholar
Morrison, G. L. & McLaughlin, D. K. 1980 Instability process in low Reynolds number supersonic jets. A.I.A.A. J. 18, 793–800.Google Scholar
Petersen, R. A. 1978 Influence of wave dispersion on vortex pairing in a jet. J. Fluid Mech. 89, 469–495.Google Scholar
Phillips, O. M. 1960 On the generation of sound by supersonic turbulent shear layers. J. Fluid Mech. 9, 1–28.Google Scholar
Potter, R. C. 1968 An investigation to locate the acoustic sources in a high speed jet exhaust stream. Wyle Lab. Tech. Rep. WR 68–4.Google Scholar
Rose, W. C. 1973 The behavior of a compressible turbulent boundary layer in a shock-wave-induced adverse pressure gradient. N.A.S.A. TN D-7092.
Salant, R. F. 1973 Investigation of jet noise using optical holography. Dept of Transportation Rep. no. DOT-TSC-OST-73–11.Google Scholar
Sedel'Nikov, T. K. 1967 The frequency spectrum of the noise of a supersonic jet. Phys. Aero. Noise. Moscow: Nauka. (Trans. N.A.S.A. TTF-538, 1969, pp. 71–75.)
Stromberg, J. L., McLaughlin, D. K. & Troutt, T. R. 1979 Flowfield and acoustic properties of a Mach number 09 jet at a low Reynolds number. A.I.A.A. Paper no. 79–0593.Google Scholar
Tam, C. K. W. 1971 Directional acoustic radiation from a supersonic jet generated by shear layer instability. J. Fluid Mech. 46, 757–768.Google Scholar
Tam, C. K. W. 1972 On the noise of a nearly ideally expanded supersonic jet. J. Fluid Mech. 51, 69–95.Google Scholar
Tam, C. K. W. 1975 Supersonic jet noise generated by large scale disturbances. J. Sound Vib. 38, 51–79.Google Scholar
Tester, B. J., Morris, P. J., Lau, J. C. & Tanna, H. K. 1978 The generation, radiation and prediction of supersonic jet noise, 1. Tech. Rep. AFAPL-TR-78–85.Google Scholar
Troutt, T. R. 1978 Measurements on the flow and acoustic properties of a moderate Reynolds number supersonic jet. Ph.D. dissertation, Oklahoma State University, Stillwater, Oklahoma.
Yu, J. C. & Dosanjh, D. S. 1972 Noise field of supersonic Mach 15 cold model jet. J. Acoust. Soc. Am. 51, 1400–1410.Google Scholar