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On the inviscid instability of a circular jet with external flow

Published online by Cambridge University Press:  20 April 2006

Alfons Michalke  and
Gunter Hermann
Alfons Michalke
Affiliation:
Hermann-Föttinger-Institut für Thermo- und Fluiddynamik, Technische Universität Berlin, West Germany
Gunter Hermann
Affiliation:
Wien, Austria
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Abstract

The influence of an external flow velocity on the instability of a circular jet has been investigated by means of the inviscid linearized stability theory. The instability properties of spatially growing axisymmetric and first-order azimuthal disturbances show that the external flow inhibits the instability of the circular jet, but increases the unstable frequency range. Similarity considerations lead to the result that, in a first approximation, the disturbed flow field is independent of the external flow velocity, if the axial co-ordinate is contracted by a suitably chosen stretching factor and if the disturbance frequency is reduced by the same factor. It is concluded that the large-scale structure of jet turbulence is modified in the same manner by the external flow.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 114 , January 1982 , pp. 343 - 359
Copyright
© 1972 Cambridge University Press

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References

Armstrong, R. R. 1977 Einfluß der Machzahl auf die kohärente Turbulenzstruktur eines runden Freistrahls. Dissertation, Technische Universität Berlin.
Armstrong, R. R., Michalke, A. & Fuchs, H. V. 1977 Coherent structures in jet turbulence and noise. A.I.A.A. J. 15, 1011–1017.Google Scholar
Bechert, D. & Pfizenmaier, E. 1975 On wavelike perturbations in a free jet travelling faster than the mean flow in the jet. J. Fluid Mech. 72, 341–352.Google Scholar
Betchov, R. & Criminale, W. O. 1967 Stability of Parallel Flows. Academic.
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
Ffowcs Williams, J. E. 1963 The noise from turbulence convected at high speed. Phil. Trans. R. Soc. Lond. A 225, 469–503.Google Scholar
Fuchs, H. V. 1972 Space correlations of the fluctuating pressure in subsonic jets. J. Sound Vib. 22, 77–99.Google Scholar
Ko, N. W. M. & Davies, P. O. A. L. 1975 Some covariance measurements in a subsonic jet. J. Sound Vib. 41, 347–358.Google Scholar
Michalke, A. 1971 Instabilität eines runden Freistrahls unter Berücksichtigung des Einflusses der Strahlgrenzschichtdicke. Z. Flugwiss. 19, 319–328. [English Translation: Instability of compressible circular free jet with consideration of the influence of the jet boundary layer thickness. N.A.S.A. Tech. Memo. 75190, 1977.Google Scholar
Michalke, A. & Michel, U. 1979 Prediction of jet noise in flight from static tests. J. Sound Vib. 67, 341–367.Google Scholar
Mollo-Christensen, E. 1967 Jet noise and shear flow instability seen from an experimenter's viewpoint. Trans. A.S.M.E. E, J. Appl. Mech. 89, 1–7.Google Scholar
Moore, C. J. 1977 The role of shear-layer instability waves in jet exhaust noise. J. Fluid Mech. 80, 321–367.Google Scholar
Morris, P. J. 1976 The spatial viscous instability of axisymmetric jets. J. Fluid Mech. 77, 511–529.Google Scholar
Plaschko, P. 1979 Helical instabilities of slowly divergent jets. J. Fluid Mech. 92, 209–215.Google Scholar
Sarohia, V. 1979 Flight effects on subsonic jet noise. A.I.A.A. Paper no. 79-0616.Google Scholar
Sarohia, V. & Massier, P. F. 1977 Effects of external boundary-layer flow on jet noise in flight. A.I.A.A. J. 15, 659–664.Google Scholar
Squire, H. B. & Trouncer, J. 1944 Round jets in a general stream. ARC Rep. Mem. no. 1974.Google Scholar
Stromberg, J. L., McLaughlin, D. K. & Troutt, T. R. 1980 Flow field and acoustic properties of a Mach number 0×9 jet at low Reynolds number. J. Sound Vib. 72, 159–176.Google Scholar
Tanna, H. K. & Morris, P. J. 1977 In-flight simulation experiments on turbulent jet mixing noise. J. Sound Vib. 53, 389–405.Google Scholar
Yule, A. J. 1972 Spreading of turbulent mixing layers. A.I.A.A. J. 10, 686–687.Google Scholar