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On the Noise Emanating from a Two-Dimensional Jet Above the Critical Pressure

Published online by Cambridge University Press:  07 June 2016

Alan Powell*
Affiliation:
Department of Aeronautical Engineering, University of Southampton
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Summary

Schlieren photographs of a small scale approximately two-dimensional air jet in air above the critical pressure have shown the existence of an instability displaying an anti-symmetric pattern, and the associated sound field having several distinguishing characteristics, has been photographed. An elementary theory based upon the hypothesis that the acoustic energy originates from the interaction of the stream disturbances with the shock waves of the flow, and connecting the stream disturbances with the radiated sound, is suggested. This is shown to be consistent with the physical dimensions of the phenomenon and predicts a sound field in reasonable agreement with that observed after certain simplifying assumptions have been made.

Type
Research Article
Copyright
Copyright © Royal Aeronautical Society. 1953

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References

1. Powell, A. (1951). A “Schlieren” Study of Small Scale Air Jets and Some Noise Measurements on Two-inch Diameter Air Jets. A.R.C. 14,726, F.M. 1694.Google Scholar
2. Pack, D. C. (1948). On the Formation of Shock Waves in Supersonic Gas Jets. Quarterly Journal of Mechanics and Applied Mathematics, 1, p. 1, 1948.Google Scholar
3. Hilton, W. F. (1940). Measurements of Noise from Aerofoils and Streamline Wires. Phil. Mag., 30, p. 237, 1940.Google Scholar
4. Holder, W. and North, R. J. (1949). An Oscillatory Flow Resulting from the Interaction of Shockwaves with the Boundary Layers on a Rigid Aerofoil. A.R.C. 12,409, F.M. 1366.Google Scholar
5. Brown, G. B. (1935). Vortex Motion in Gaseous Jets and the Origin of their Sensitivity to Sound. Proc. Phy. Soc, 47, p. 703, 1935.CrossRefGoogle Scholar
6. Brown, G. B. (1932). On Sensitive Flames. Phil. Mag., 13, p. 161, 1932.Google Scholar
7. Dubois, M. (1952). Jets Gazeux Sensibles aux Sons et aux Ultra-sons. Pub. Sci. et Tech. du Min. de l'Air, No. 249, Paris.Google Scholar
8. Schubaer, G. B., and Skramstad, H. K. (1947). Laminar Boundary Layer Oscillations and Stability of Laminar Flow. Journal of the Aeronautical Sciences, Feb. 1947.CrossRefGoogle Scholar
9. Savic, P. (1941). Acoustically Effective Vortex Motion in Jets. Phil. Mag., 32, p. 245, 1941.Google Scholar
10. Pai, S. I. (1951). On the Stability of a Two-Dimensional Laminar Jet Flow of Gas. Journal of the Aeronautical Sciences, p. 731, Nov. 1951.Google Scholar
11. Rayleigh, Lord (1888). On Point-, Line-and Plane-Sources of Sound. Proc. Lond. Math. Soc, 19, p. 504, 1888.Google Scholar
12. Lighthill, M. J. (1952). On Sound Generated Aerodynamically. Proc. Roy. Soc. A., 211, p. 546, 1952.Google Scholar