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Cavitation phenomena within regions of flow separation

Published online by Cambridge University Press:  20 April 2006

Joseph Katz
Joseph Katz
Affiliation:
California Institute of Technology, Pasadena, California 91125 Present address: School of Civil Engineering, Purdue University, West Lafayette, Indiana.
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Abstract

The phenomenon of cavitation inception was studied on four axisymmetric bodies whose boundary layers underwent a laminar separation and subsequent turbulent reattachment. The non-cavitating flow was studied by holographic and schlieren flow-visualization techniques. Surface distributions on the mean and the fluctuating pressures were also measured. The conditions for cavitation inception and desinence were determined and holograms were recorded just prior to and at the onset of cavitation. The population of microbubbles and the subsequent development of visible cavitation was determined from the reconstructed image. In every case the appearance of visible cavitation was preceded by a cluster of microscopic bubbles in a small portion of the flow field providing clear evidence that cavitation is initiated from small nuclei. The inception zone was located within the turbulent shear layer downstream of transition and upstream of the reattachment region of the bodies with large separation regions. The location and the shape of this cavitation suggested a relation to the mixing-layer eddy structure. The inception region on the body with the smallest separation zone, a hemisphere-cylinder body, was located in the reattachment region, but the cavities were still detached from the surface. Instantaneous minimum-surface-pressure measurements do not account for observed cavitation-inception indices except for the hemisphere body, where the correlation is satisfactory. The rate of cavitation events was estimated from measurements of nuclei population, and fluctuating-pressure statistics in the portion of the flow susceptable to cavitation. It was demonstrated for the hemisphere body that at least one such cavitation event could occur every second. These findings are consistent with what is observed visually at the onset of cavitation and support the location of inception determined holographically.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 140 , March 1984 , pp. 397 - 436
Copyright
© 1984 Cambridge University Press

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References

Arakeri, V. H. 1973 Viscous effects in inception and development of cavitation on axi-symmetric bodies. Ph.D. dissertation, California Institute of Technology.
Arakeri, V. H. 1975 A note on the transition observations on an axisymmetric body and some related fluctuating wall pressure measurements. Trans. ASME I: J. Fluids Engng 97, 82–87.Google Scholar
Arakeri, V. H. 1979 Inception of cavitation from a backward facing step. Intl Symp. on Cavitation Inception. ASME Winter Annual Meeting. N.Y., 2–7 December.Google Scholar
Arakeri, V. H. & Acosta, A. J. 1979 Viscous effects in the inception of cavitation. Int. Symp. on Cavitation Inception, ASME Winter Annual Meeting, N. Y., 2–7 December.Google Scholar
Arndt, R. E. A. 1976 Semi-empirical analysis of cavitation in the wake of a sharp-edged disk. Trans. ASME I: J. Fluids Engng 98, 560–562.Google Scholar
Arndt, R. E. A. 1981 Cavitation in fluid machinery and hydraulic structures. Ann. Rev. Fluid Mech. 13, 273–328.Google Scholar
Arndt, R. E. A. & George, W. K. 1978 Pressure fields and cavitation in turbulent shear flows. In Proc. 12th Symp. Naval Hydrodyn. Washington, D.C., pp. 327–339.
Bernal, L. P. 1981 The coherent structure of turbulent mixing layers. Ph.D. dissertation, Graduate Aeronautical Laboratories, California Institute of Technology.
Breidenthal, R. E. 1978 A chemically reacting turbulent shear layer. Ph.D. dissertation, California Institute of Technology.
Brown, G. L. & Roshko, A. 1974 On density effects and large structure in turbulent mixing layers. J. Fluid Mech. 64, 775–816.Google Scholar
Collier, R. J., Burkhardt, C. B. & Lin, L. H. 1971 Optical Holography. Academic.
Gates, E. M. 1977 The influence of freestream turbulence, freestream nuclei populations and a drag-reducing polymer on cavitation inception on two axisymmetric bodies. California Inst. Tech. Rep. 183–2 (April).Google Scholar
Holl, W. J. & Carroll, J. A. 1979 Observation of the various types of limited cavitation on axisymmetric bodies. Int. Symp. on Cavitation Inception, ASME Winter Annual Meeting, N. Y., 2–7 December.Google Scholar
Huang, T. T. 1979 Cavitation inception observations on six axisymmetric bodies. Intl Symp. on Cavitation Inception, ASME Winter Annual Meeting, N.Y., 2–7 December.Google Scholar
Katz, J. 1981 Cavitation inception in separated flows. Ph.D. dissertation, California Institute of Technology.
Katz, J. & O'Hern, T. J. 1983 Cavitation in large scale shear flows: ASME Pub. 83-FE-33.
Kermeen, R. W. & Parkin, B. R. 1957 Incipient cavitation and wake flow behind sharp edge disks. California Inst. Tech. Hydrodyn. Lab. Rep. 85–4 (August).Google Scholar
Knapp, R. T., Daily, J. W. & Hammitt, F. G. 1970 Cavitation. McGraw-Hill.
Konrad, J. H. 1976 An experimental investigation of mixing in two dimensional turbulent shear flows with applications to diffusion-limited chemical reactions. Ph.D. thesis, California Institute of Technology; Project SQUID Tech. Rep. CIT-8-PU.
Moore, B. W. & Saffman, P. G. 1975 The density of organized vortices in a turbulent mixing layer. J. Fluid Mech. 69, 465–473.Google Scholar
Ota, T. 1975 An axisymmetric separated and reattached flow on a longitudinal blunt circular cylinder. Trans. ASME E: J. Appl. Mech. 42, 311–315.Google Scholar
Parkin, B. R. & Kermeen, R. W. 1953 Incipient cavitation and boundary layer interaction on a streamlined body. California Inst. Tech., Hydrodyn. Lab. Rep. E-35.2 (December).Google Scholar
Plesset, M. S. & Prosperetti, A. 1977 Bubble dynamics and cavitation. Ann. Rev. Fluid Mech. 9, 145–185.Google Scholar
Van der Meulen, J. H. J. 1976 A holographic study of cavitation on axisymmetric bodies and the influence on polymer additives. Netherlands Ship Model Basin, Pub. 509, Wageningen, The Netherlands.