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Oscillations of a moderately underexpanded choked jet impinging upon a flat plate

Published online by Cambridge University Press:  26 April 2006

Chih-Yu Kuo  and
Ann P. Dowling
Chih-Yu Kuo
Affiliation:
Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ, UK
Ann P. Dowling
Affiliation:
Cambridge University Engineering Department, Trumpington Street, Cambridge CB2 1PZ, UK
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Abstract

The oscillation of a moderately underexpanded choked jet impinging upon a flat plate is investigated both analytically and numerically. The feedback mechanism between oscillations of the standoff-shock and the plate is clarified. Pressure waves produced by the motion of the shock are reflected by the plate. In addition, oscillations in the shock position lead to downstream entropy fluctuations, which generate pressure waves as they are convected through the stagnation flow near the plate. A linear stability analysis is used to investigate the stability threshold and frequencies of oscillation, as a function of jet pressure ratio and nozzle-to-plate distance. The analytical predictions are compared to results from a numerical simulation and to the experimental data of Powell (1988) and Mørch (1963, 1964).

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 315 , 25 May 1996 , pp. 267 - 291
Copyright
© 1996 Cambridge University Press

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References

Carling, J. C. & Hunt, B. L. 1974 The near wall jet of a normally impinging uniform, axisymmetric supersonic jet. J. Fluid Mech. 66, 159–176.Google Scholar
Chanaud, R. C. & Powell, A. 1963 Some experiments concerning the hole and ring tone. J. Acoust. Soc. Am. 37, 901–911.Google Scholar
Denton, J. D. 1993 VIB3D, method for calculating 3-D unsteady flow through turbomachinery blades. Cambridge Univ. Eng. Dept. Tech. Rep.
Glaznev, V. N. 1977 Sound field of an underexpanded supersonic jet impinging on a barrier. Sov. Phys. Acoust. 23, 142–145.Google Scholar
Glaznev, V. N., Demin, V. S. & Yakushev, A. M. 1977 Self-oscillations in an underexpanded jet flowing into a barrier. Fluid Dyn. USSR. 12, 848–852.Google Scholar
Gummer, J. H. & Hunt, B. L. 1971 The impingement of a uniform, axisymmetric, supersonic jet on a perpendicular flat plate. Aeronaut. Q. 22, 403–420.Google Scholar
Hartmann, J. 1939 The acoustic air-jet generator. Ingeniorvidenskabelige Skrifter, No. 4.
Hartmann, J. & Trolle, B. 1927 A new acoustic generator. The air-jet generator. J. Sci. Instrum. 4, 101–111.Google Scholar
Henderson, B. & Powell, A. 1993 Experiments concerning tones produced by an axisymmetric choked jet impinging on flat plates. J. Sound Vib. 168, 307–326.Google Scholar
Ho, C. M. & Nosseir, N. S. 1981 Dynamics of an impinging jet. Part 1. The feedback phenomenon. J. Fluid Mech. 105, 119–142.Google Scholar
Howe, M. S. 1975 Contributions to the theory of aerodynamic sound, with application to excess jet noise and the theory of the flute. J. Fluid Mech. 71, 625–673.Google Scholar
Kalghatgi, G. T. & Hunt, B. L. 1976 The occurrence of stagnation bubbles in supersonic jet impingement flows. Aeronaut. Q. 27, 169–185.Google Scholar
Mørch, K. A. 1963 Shock instability in the Hartmann air-jet generator. Fluid Mech. Lab. Tech. Univ. Denmark. LFM R 63–2.
Mørch, K. A. 1964 A theory for the mode of operation of the Hartmann air jet generator. J. Fluid Mech. 20, 141–159.Google Scholar
Mørch, K. A. 1973 On the impingingement of a composite jet. Tech. Univ. Denmark. DCAMM Rep. 47.
Powell, A. 1988 The sound-producing oscillations of round underexpanded jets impinging on normal plates. J. Acoust. Soc. Am. 83, 515–533.Google Scholar
Rockwell, D. & Naudascher, E. 1979 Self-sustained oscillations of impinging free shear layers. Ann. Rev. Fluid Mech. 11, 67–94.Google Scholar
Shapiro, A. H. 1954 The Dynamics and Thermodynamics of Compressible Fluid Flow, vol II. The Ronald Press Company, New York.
Tam, C. K. W. & Ahuja, K. K. 1990 Theoretical model of discrete tone generation by impinging jets. J. Fluid Mech. 214, 67–87.Google Scholar
Taylor, K. 1978 A transformation of the acoustic equation with implications for wind-tunnel and low-speed flight tests. Proc. R. Soc. Lond. A 363, 271–281.Google Scholar