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An experimental investigation of the instability of an incompressible, separated shear layer

Published online by Cambridge University Press:  28 March 2006

F. K. Browand
F. K. Browand
Affiliation:
Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, Cambridge, Massachusetts
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Abstract

The investigation of a separated shear layer was undertaken to clarify the non-linear mechanisms associated with instability and transition to turbulence. Such an investigation is of practical importance since profiles which resemble the separated shear layer are a common occurrence.

A two-dimensional free shear layer was formed by separation of a laminar boundary layer from a rearward-facing step. The free-stream speed was approximately 16 ft./sec. Hot-wire measurements were made in the region directly downstream of the plate trailing edge. The measurements included mean velocity profiles, frequency spectra of the longitudinal fluctuation, and root-mean-square amplitude and phase distributions of various spectral components of the longitudinal fluctuation. Several measurements were designed to detect the presence of periodic spanwise structure.

The most important findings were:

  1. Significant non-linear distortion of the initial unstable wave occurred without periodic spanwise structure.

  2. Non-linear distortion was first manifest by the growth of a subharmonic oscillation, which was strongly intermittent. Numerous harmonics of the sub-harmonic oscillation were also present.

  3. Strong evidence suggests that secondary instabilities were present, which created still higher frequencies.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 26 , Issue 2 , October 1966 , pp. 281 - 307
Copyright
© 1966 Cambridge University Press

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References

Benney, D. J. 1961 J. Fluid Mech. 10, 20.
Betchov, R. & Szewczyk, A. 1963 Phys. Fluids 6, 139.
Bloor, M. S. 1964 J. Fluid Mech. 19, 29.
Drazin, P. G. & Howard, L. N. 1962 J. Fluid Mech. 14, 25.
Esch, R. E. 1957 J. Fluid Mech. 3, 28.
Foote, J. R. & Lin, C. C. 1950 Quart. Appl. Math. 8, 26.
Gaster, M. 1965 J. Fluid Mech. 22, 43.
Greenspan, H. P. & Benney, D. J. 1963 J. Fluid Mech. 15, 13.
Hama, F. R., Long, J. D. & Hegarty, J. C. 1957 J. Appl. Phys. 28, 38.
Kelly, R. E. 1965 Nat. Phys. Lab. Aero Rep. no. 1161.
Klebanoff, P. S., Tidstrom, K. D. & Sargent, L. M. 1962 J. Fluid Mech. 12, 1.
Kovasznay, L. S. G. 1949 Proc. Roy. Soc., A 198, 174.
Lessen, M. & Fox, J. A. 1955 50 Jahre Grenzschichtforschung, p. 122 (eds. H. Gortler and W. Tollmien). Braunschweig: Vieweg.
Liepmann, H. W. & Laufer, J. 1947 NACA TN no. 1257.
Lin, C. C. 1953 NACA TN no. 2887.
Lin, C. C. 1955 The Theory of Hydrodynamic Stability. Cambridge University Press.
Locke, R. C. 1951 Quart. J. Mech. Appl. Math. 4, pt. 1.
Michalke, A. 1964 J. Fluid Mech. 19, 54.
Michalke, A. 1965 J. Fluid Mech. 22, 37.
Michalke, A. 1966 To be published. J. Fluid Mech.Google Scholar
Rayleigh, Lord 1896 The Theory of Sound, volume II, 2nd ed. London: MacMillan.
Roshko, A. 1954 NACA TR no. 1191.
Sato, H. 1956 J. Phys. Soc. Japan, 11, 702.
Sato, H. 1959 J. Phys. Soc. Japan 14, 179.
Sato, H. 1960 J. Fluid Mech. 7, 5.
Sato, H. & Kuriki, K. 1961 J. Fluid Mech. 11, 32.
Sato, H. & Sakao, F. 1964 J. Fluid Mech. 20, 33.
Schade, H. 1964 Phys. Fluids 7, 62.
Stoker, J. J. 1950 Nonlinear Vibrations. New York: Interscience.
Stuart, J. T. 1960 J. Fluid Mech. 9, 35.
Tatsumi, T. & Gotoh, K. 1960 J. Fluid Mech. 7, 43.
Tritton, D. J. 1959 J. Fluid Mech. 6, 54.
Wehrmann, O. & Wille, R. 1958 Grenzschichtforschung, IUTAM-symposium, Freiburg 1957, p. 387. Berlin: Springer.