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The organized nature of flow impingement upon a corner

Published online by Cambridge University Press:  18 April 2017

D. Rockwell  and
C. Knisely
D. Rockwell
Affiliation:
Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, Pa. 18015, U.S.A.
C. Knisely
Affiliation:
Department of Mechanical Engineering and Mechanics, Lehigh University, Bethlehem, Pa. 18015, U.S.A.
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Extract

Oscillations of impinging flows, which date back to the jet-edge phenomenon (Sondhaus 1854), have been observed for a wide variety of impingement configurations. However, alteration of the structure of the shear layer due to insertion of an impingement edge (or surface) and the mechanics of impingement of vortical structures upon an edge have remained largely uninvestigated. In this study, the impingement of a shear layer upon a cavity edge (or corner) is examined in detail. Water is used as a working fluid and laser anemometry and hydrogen bubble flow visualization are used to characterize the flow dynamics. Reynolds numbers (based on momentum thickness at separation) of 106 and 324 are employed. Without the edge, the shear layer produces the same sort of non-stationary (variable) velocity autocorrelations observed by Dimotakis & Brown (1976). When the edge is inserted, the organization of the flow is dramatically enhanced as evidenced by a decrease in variability of autocorrelations and appearance of well-defined peaks in the corresponding spectra. This enhanced organization is not locally confined to the region of the edge but extends along the entire length of the shear layer, thereby reinforcing the concept of disturbance feedback. Comparison of spectra with and without insertion of the edge reveals a remarkable similarity to those of a non-impinging shear layer with and without application of sound at a discrete frequency (Browand 1966; Miksad 1972); with enhanced organization at the fundamental frequency, simultaneous enhancement occurs also at the sub- and higher-harmonics.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 93 , Issue 3 , August 1979 , pp. 413 - 432
Copyright
Copyright © Cambridge University Press 1979

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References

Beabman, P. W. 1972 Some Measurements Of The Distortion Of Turbulence Approaching A Two-Dimensional Bluff Body. J. Fluid Mech. 53, 451–467.CrossRefGoogle Scholar
Bbowand, F. 1966 An Experimental Investigation Of The Instability Of An Incompressible, Separated Shear Layer. J. Fluid Mech. 26, 281–307.CrossRefGoogle Scholar
Bbowand, F. K. & Weidman, P. D. 1976 Large Scales In The Developing Mixing Layer. J. Fluid Mech. 76, 127–144.CrossRefGoogle Scholar
Chandbsttda, C, Mehta, R. D., Weir, A. D. & Bradshaw, P. 1978 Effect Of Free-Stream Turbulence On Large Structure In Turbulent Mixing Layers. J. Fluid Mech. 85, 693–704.Google Scholar
Davies, P. O. A. L. & Yule, A. J. 1975 Coherent Structures In Turbulence. J. Fluid Mech. 69, 513–537.CrossRefGoogle Scholar
Dimotakis, P. E. & Bbown, G. L. 1976 The Mixing Layer At High Reynolds Number: Large Structure Dynamics And Entrainment. J. Fluid Mech. 78, 535–560.CrossRefGoogle Scholar
Durst, F., Melling, A. & Whitelaw, J. H. 1976 Principles And Practice Of Laser-Doppler Anemometry. London: Academic Press.Google Scholar
Fbeymtjth, P. 1966 On Transition In A Separated Laminar Boundary Layer. J. Fluid Mech. 25, 683–704.Google Scholar
Heller, H. H. & Bliss, D. 1975 The Physical Mechanism Of Flow-Induced Pressure Fluctuations In Cavities And Concepts For Their Suppression. A.I.A.A. Paper 75-491, A.I.A.A. 2nd Aero-Acoustics Conf., Hampton, Va., March 24–26.Google Scholar
Holdeman, J. D. & Foss, J. F. 1975 The Initiation, Development, And Decay Of Secondary Flow In A Bounded Jet. Trans. A.8.M.E. I, J. Fluid Engng 97, 342–352.CrossRefGoogle Scholar
Htjssain, A. K. M. F. & Zaman, K. B. M. A. 1978 The Free Shear Layer Tone Phenomenon And Probe Interference. J. Fluid Mech. 87, 349–383.Google Scholar
Karamcheti, K., Bauer, A. B., Shields, W. C., Stegen, G. R. & Woolley, J. P. 1969 Some Basic Features Of An Edge-Tone Flow Field. Basic Aerodyn. Noise Res., N.A.S.A. Sp-207, Conf. N.A.S.A. Headquarters, Washington, B.C., July 14-15, Pp. 275–304.Google Scholar
Konrad, J. H. 1976 An Experimental Investigation Of Mixing In Two-Dimensional Turbulent Shear Flows With Applications To Diffusion-Limited Chemical Reactions. Project Squid Tech. Rep. Cit-8-Pu.Google Scholar
Michaxke, A. 1965 On Spatially Growing Disturbances In An Inviscid Shear Layer. J. Fluid Mech. 23, 521–544.CrossRefGoogle Scholar
Miksad, R. W. 1972 Experiments On The Nonlinear Stages Of Free Shear-Layer Transition. J. Fluid Mech. 56, 695–719.CrossRefGoogle Scholar
Powell, A. 1961 On The Edgetone. J. Acoustical Soc. America, 33, 395–409.CrossRefGoogle Scholar
Rockwell, D. 1976 Vortex Stretching Due To Shear Layer Instability. Trans. A.S.M.E. I, J. Fluids Engng 99, 240–244.CrossRefGoogle Scholar
Rockwell, D. & Knisely, C. 1979 Three-Dimensional Features Of A Cavity Shear Layer. To Appear In Phys. Fluids. Google Scholar
Rockwell, D. & Naudascher, E. 1978 Review - Self-Sustaining Oscillations Of Flow Past Cavities. Trans. A.S.M.E., J. Fluids Engng 100, 152–165.CrossRefGoogle Scholar
Rockwell, D. & Naudascher, E. 1979 Self-Sustained Oscillations Of Impinging Free Shear Layers. Ann. Rev. Fluid Mech. 11, 67–94.CrossRefGoogle Scholar
Rockwell, D. & Niccolls, W. 1972 Natural Breakdown Of Planar Jets. Trans. A.S.M.E. D, J. Basic Engng 94, 720–730.Google Scholar
Roshko, A. 1976 Structure Of Turbulent Shear Flows: A New Look. A.I.A.A. J. 14, 1349–1357.Google Scholar
Sarohia, V. 1977 Experimental Investigation Of Oscillations In Flows Over Shallow Cavities. A.I.A.A. J. 15, 984–991.Google Scholar
Sarohia, V. & Massier, P. F. 1975 Control Of Cavity Noise. A.I.A.A. Paper 75-528, Presented At 3rd A.I.A.A. Aero-Acoustics Conf., Palo Alto, California. July 20–23.Google Scholar
Sondhaus, C. 1854 Ueber Die Beim Ausstroemen Der Luft Entstehenden Tone. Ann. Phys. (Leipzig) 91, Pp. 214–240.CrossRefGoogle Scholar
Stuart, J. T. 1967 On Finite Amplitude Oscillations In Laminar Mixing Layers. J. Fluid Mech. 29, 417–440.CrossRefGoogle Scholar
Winant, C. D. & Browand, F. K. 1974 Vortex Pairing: The Mechanism Of Turbulent Mixing Layer Growth At Moderate Reynolds Number. J. Fluid Mech. 63, 237–255.CrossRefGoogle Scholar