Hostname: page-component-745bb68f8f-grxwn Total loading time: 0 Render date: 2025-01-09T19:21:43.234Z Has data issue: false hasContentIssue false
  • English
  • Français

The effect of flow oscillations on cavity drag

Published online by Cambridge University Press:  21 April 2006

M. Gharib  and
A. Roshko
M. Gharib
Affiliation:
Graduate Aeronautical Laboratories, California Institute of Technology, Pasadena, CA 91125, USA Present address: Department of Applied Mechanics and Engineering Sciences, University of California, San Diego, La Jolla, California 92093, USA.
A. Roshko
Affiliation:
Graduate Aeronautical Laboratories, California Institute of Technology, Pasadena, CA 91125, USA
Get access Rights & Permissions [Opens in a new window]

Abstract

An experimental investigation of flow over an axisymmetric cavity shows that self-sustained, periodic oscillations of the cavity shear layer are associated with low cavity drag. In this low-drag mode the flow regulates itself to fix the mean-shear-layer stagnation point at the downstream corner. Above a critical value of the cavity width-to-depth ratio there is an abrupt and large increase of drag due to the onset of the ‘wake mode’ of instability. It is also shown by measurement of the momentum balance how the drag of the cavity is related to the state of the shear layer, as defined by the mean momentum transport $\rho\overline{u}\overline{v}$ and the Reynolds stress $\rho\overline{u^{\prime}v^{\prime}}$, and how these are related to the amplifying oscillations in the shear layer. The cavity shear layer is found to be different, in several respects, from a free shear layer.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 177 , April 1987 , pp. 501 - 530
Copyright
© 1987 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

Bradshaw, P. 1966 The effect of initial conditions on the development of a free shear layer. J. Fluid Mech. 26, 225.Google Scholar
Browand, F. K. 1966 An experimental investigation of the instability of an incompressible, separated shear layer. J. Fluid Mech. 26, 281.Google Scholar
Dewey, C. F. 1976 Qualitative and quantitative flow field visualization utilizing laser-induced fluorescence. AGARD-CP-193, 17–1.
Dimotakis, P. E., Miake-Lye, R. C. & Papantoniou, D. A. 1983 Structure and dynamics of round turbulent jets. Phys. Fluids 26(11), 3185.Google Scholar
Dimotakis, P. E. & Brown, G. L. 1976 The mixing layer at high Reynolds number; large-structure dynamics and entrainment. J. Fluid Mech. 78(3), 535.Google Scholar
Fox, J. 1968 A criterion for the transition between flow regimes in turbulent cavity flow. AIAA J. 4(2), 364.Google Scholar
Freymuth, P. 1966 On transition in a separated laminar boundary layer. J. Fluid Mech. 25, 683.Google Scholar
Gharib, M. 1983 The effect of flow oscillations on cavity drag and a technique for its control. Ph.D. thesis, California Institute of Technology, Pasadena, CA.
Gharib, M. 1987 Response of the cavity shear layer oscillations to external forcing. AIAA J. 25, 43.Google Scholar
Ho, C. M. & Huang, L. S. 1982 Subharmonics and vortex merging in mixing layers. J. Fluid Mech. 119, 443.Google Scholar
Karamcheti, K. 1956 Sound radiated from surface cutouts in high-speed flows. Ph.D. thesis, California Institute of Technology, Pasadena, CA.
Kistler, A. L. & Tan, F. C. 1967 Some properties of turbulent separated flows. Phys. Fluids Suppl. 165.
Knisely, C. W. 1980 An experimental investigation of low frequency self-modulation of incompressible impinging cavity shear layers. Ph.D. dissertation, Lehigh University, Bethlehem, PA.
Koenig, K. & Roshko, A. 1985 An experimental study of geometrical effects on the drag and flow field of two bluff bodies separated by a gap. J. Fluid Mech. 156, 167.Google Scholar
Liepmann, H. W. & Laufer, J. 1947 Invetigations of free turbulent mixing. NACA Tech. Note no. 1257.
Michalke, A. 1965 On spatially growing disturbances in an inviscid shear layer. J. Fluid Mech. 23, 521.Google Scholar
Oster, D. & Wygnanski, I. 1982 The forced mixing layer between parallel streams. J. Fluid Mech. 123, 91.Google Scholar
Rockwell, D. & Knisely, C. 1979 The organized nature of flow impingement upon a corner. J. Fluid Mech. 93, 413.Google Scholar
Rockwell, D. & Naudascher, E. 1978 Review self-sustaining oscillations of flow past cavities. Trans. ASME I: J. Fluid Engng 100, 152Google Scholar
Roshko, A. 1955 Some measurements of flow in a rectangular cutout. NACA TN 3488.
Sarohia, V. 1975 Experimental and analytical investigation of oscillations in flows over cavities. Ph.D. thesis, California Institute of Technology, Pasadena, CA.
Sarohia, V. & Massier, P. E. 1976 Control of cavity noise. AIAA Paper 76–528. Presented at 3rd AIAA Aero-Acoustics Conf., Palo Alto, 20–23 July, 1976.
Sarohia, V. & Massier, P. E. 1977 Investigation of pressure oscillations in axi-symmetric cavity flows. Harry Diamond Laboratories Rpt. HDL-CR-77–025–1.
Stuart, J. T. 1967 On finite amplitude oscillations in laminar mixing layers. J. Fluid Mech. 29, 417.Google Scholar
Werle, H. 1974 Le tunnel hydrodynamique au service de la recherche aerospatiale. Publ. no. 156, ONERA, France.
Woolley, J. P. & Karamcheti, K. 1973 The role of jet stability in edgetone generation. AIAA Paper 73–628, AIAA 6th Fluid and Plasma Dynamics Conf. 16–18 July, Palm Springs, CA.
Wygnanski, I. & Fiedler, H. E. 1970 The two-dimensional mixing region. J. Fluid Mech. 41, 327.Google Scholar
Ziada, S. & Rockwell, D. 1981 Generation of higher harmonics in a self-oscillating mixing layer edge system. AIAA J. 20(2), 196.Google Scholar