Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-19T11:59:27.907Z Has data issue: false hasContentIssue false
  • English
  • Français

Experiments on the instability waves in a supersonic jet and their acoustic radiation

Published online by Cambridge University Press:  29 March 2006

Dennis K. Mclaughlin ,
Gerald L. Morrison  and
Timothy R. Troutt
Dennis K. Mclaughlin
Affiliation:
Oklahoma State University, Stillwater, Oklahoma
Gerald L. Morrison
Affiliation:
Oklahoma State University, Stillwater, Oklahoma
Timothy R. Troutt
Affiliation:
Oklahoma State University, Stillwater, Oklahoma
Get access Rights & Permissions [Opens in a new window]

Abstract

An experimental investigation of the instability and the acoustic radiation of the low Reynolds number axisymmetric supersonic jet has been performed. Hot-wire measurements in the flow field and microphone measurements in the acoustic field were obtained from different size jets at Mach numbers of about 2. The Reynolds number ranged from 8000 to 107000, which contrasts with a Reynolds number of 1·3 × 106 for similar jets exhausting into atmospheric pressure.

Hot-wire measurements indicate that the instability process in the perfectly expanded jet consists of numerous discrete frequency modes around a Strouhal number of 0·18. The waves grow almost exponentially and propagate downstream at a supersonic velocity with respect to the surrounding air. Measurements of the wavelength and wave speed of the St = 0·18 oscillation agree closely with Tam's theoretical predictions.

Microphone measurements have shown that the wavelength, wave orientation and frequency of the acoustic radiation generated by the dominant instability agree with the Mach wave concept. The sound pressure levels measured in the low Reynolds number jet extrapolate to values approaching the noise levels measured by other experimenters in high Reynolds number jets. These measurements provide more evidence that the dominant noise generation mechanism in high Reynolds number jets is the large-scale instability.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 69 , Issue 1 , 13 May 1975 , pp. 73 - 95
Copyright
© 1975 Cambridge University Press

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

Behrens, W. 1963 Viscous interaction effect on a static pressure probe at M = 6. A.I.A.A. J. 1, 2364–2366.Google Scholar
Behrens, W. 1968 Far wake behind cylinders at hypersonic speeds. II. Stability A.I.A.A. J. 6, 225–232.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
Chan, Y. Y. & Westley, R. 1973 Directional acoustic radiation generated by spatial jet instability CASI Trans. 6, 36–41.Google Scholar
Crow, S. C. & Champagne, F. H. 1971 Orderly structure in jet turbulence J. Fluid Mech. 48, 547–591.Google Scholar
Dewey, C. F. 1965 A correlation of convective heat transfer and recovery temperature data for cylinders in compressible flow Int. J. Heat Mass Transfer, 8, 245–252.Google Scholar
Dosanjh, D. S. & Yu, J. C. 1968 Noise from underexpanded axisymmetric jet flow using radial jet impingement. Proc. AFOSR-UTIAS Symp. on Aerodynamic Noise. Toronto, Canada.Google Scholar
FFOWCS WILLIAMS, J. E. 1963 The noise from turbulence convected at high speed. Phil. Trans. A 255, 459.Google Scholar
Kendall, J. M. 1967 Supersonic boundary layer stability experiments. Proc. Boundary Layer Trans. Study Group, Meeting, II, Aerospace Rep. TR-0158 (S3816–63)-1.Google Scholar
Lee, H. K. & Ribner, H. S. 1972 Direct correlation of noise and flow of a jet J. Acoust. Soc. Am. 52, 1280–1290.Google Scholar
Lighthill, M. J. 1952 On sound generated aerodynamically. I. General theory. Proc. Roy. Soc A 211, 564–587.Google Scholar
Lighthill, M. J. 1954 On sound generated aerodynamically. II. Turbulence as a source of sound. Proc. Roy. Soc A 222, 1–32.Google Scholar
Lilley, G. M., Morris, P. & Tester, B. J. 1973 On the theory of jet noise and its applications. A.I.A.A. Paper, no. 73–987.Google Scholar
Louis, J. F., Letty, R. P. & Patel, J. R. 1972 A systematic study of supersonic jet noise. A.I.A.A. Paper, no. 72–641.Google Scholar
Mclaughlin, D. K. 1971 Experimental investigation of the stability of the laminar supersonic cone wake A.I.A.A. J. 9, 696–702.Google Scholar
Mclaughlin, D. K. & Mccolgan, C. J. 1974 Hot-wire measurements in a supersonic jet at low Reynolds numbers A.I.A.A. J. 12, 1279–1281.Google Scholar
Matthews, M. L. 1958 An experimental investigation of viscous effects on static and impact pressure probes in hypersonic flow. GALCIT, Hypersonic Research Project, Memo. no. 44. Pasadena, California.Google Scholar
Mayes, W. H., Lanford, W. D. & Hubbard, H. H. 1959 Near field and far field noise surveys of solid fuel rocket engines for a range of nozzle exit pressures. N.A.S.A. Tech. Note, no. D-21.Google Scholar
Morkovin, M. W. 1956 Fluctuations and hot-wire anemometry in compressible flows. AGARDograph, no. 24.Google Scholar
Phillips, O. M. 1960 On the generation of sound by supersonic turbulent shear layers J. Fluid Mech. 9, 1–28.Google Scholar
Ribner, H. S. 1969 Eddy-Mach wave noise from a simplified model of a supersonic mixing layer. Basic Aerodynamic Noise Research, N.A.S.A. SP-207.Google Scholar
SEDEL'NIKOV, T. K. 1967 The frequency spectrum of the noise of a supersonic jet. Phy. Aero. Noise. Moscow: Nauka. (Trans. 1969 N.A.S.A. TTF-538, 71–75.)
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. 1973 Supersonic jet noise generated by large scale disturbances. A.I.A.A. Paper, no. 73–992.Google Scholar
Yu, J. C. & Dosanjh, D. S. 1972 Noise field of a supersonic Mach 1·5 cold model jet J. Acoust. Soc. Am. 51, 1400.Google Scholar