Hostname: page-component-848d4c4894-sjtt6 Total loading time: 0 Render date: 2024-07-07T10:59:11.208Z Has data issue: false hasContentIssue false
  • English
  • Français

On the mechanisms that sustain the inception of attached cavitation

Published online by Cambridge University Press:  26 August 2020

Omri Ram ,
Karuna Agarwal  and
Joseph Katz Open the ORCID record for Joseph Katz [Opens in a new window]
Omri Ram
Affiliation:
Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD21218, USA
Karuna Agarwal
Affiliation:
Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD21218, USA
Joseph Katz*
Affiliation:
Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD21218, USA
*
†Email address for correspondence: katz@jhu.edu
Get access Rights & Permissions [Opens in a new window]

Abstract

This experimental study addresses the longstanding question of why inception of attached cavitation on curved surfaces or hydrofoils at incidence is relatively insensitive to the concentration of free-stream nuclei. High-speed imaging and high-resolution particle image velocimetry measurements examine cavitation inception on three curved surfaces with varying pressure minima followed by regions with adverse pressure gradients. When these pressure gradients either thicken the boundary layer or cause local flow separation, thin $(50\text {--}60\ \mathrm {\mu }\textrm {m})$ low-momentum zones form close to the wall. Microbubbles trapped in these regions are generated initially from the collapse of intermittent attachment of travelling bubble cavitation. These bubbles migrate slowly upstream for a few milliseconds either under the influence of the adverse pressure gradients when the flow remains attached or carried by the recirculating flow when the boundary layer is separated. Their speed is only 2 %–4 % of the free-stream velocity, and their trajectories are erratic, indicating near-dynamic equilibrium. Owing to the low local pressure, their diameter increases by two to four times by non-condensable gas diffusion, from $10$ to $30\ \mathrm {\mu }\textrm {m}$ to the thickness of the low-momentum zone. At that time, either they are swept downstream by the free-stream flow or they become nuclei for new attached cavitation events. When the new patches collapse, new microbubbles form and the process repeats itself frequently, and independently of the free-stream nuclei. These phenomena do not occur when the adverse pressure gradients are too mild to create low-momentum zones with sufficient thickness to facilitate the slow upstream migration and growth.

JFM classification

Drops and Bubbles: Cavitation
Type
JFM Rapids
Information
Journal of Fluid Mechanics , Volume 901 , 25 October 2020 , R4
Check for updates
Copyright
© The Author(s), 2020. Published by 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

REFERENCES

Arakeri, V. H. & Acosta, A. J. 1973 Viscous effects in the inception of cavitation on axisymmetric bodies. Trans. ASME J. Fluids Engng 95 (4), 519–527.10.1115/1.3447065CrossRefGoogle Scholar
Arndt, R. E. A. 2002 Cavitation in vortical flows. Annu. Rev. Fluid Mech. 34 (1), 143–175.CrossRefGoogle Scholar
Blake, W. K., Wolpert, M. J. & Geib, F. E. 1977 Cavitation noise and inception as influenced by boundary-layer development on a hydrofoil. J. Fluid Mech. 80 (4), 617–640.10.1017/S0022112077002390CrossRefGoogle Scholar
Brennen, C. E. 2013 Cavitation and Bubble Dynamics. Cambridge University Press.10.1017/CBO9781107338760CrossRefGoogle Scholar
Brown, P. P. & Lawler, D. F. 2003 Sphere drag and settling velocity revisited. J. Environ. Engng 129 (3), 222–231.10.1061/(ASCE)0733-9372(2003)129:3(222)CrossRefGoogle Scholar
Ceccio, S. L. & Brennen, C. E. 1991 Observations of the dynamics and acoustics of travelling bubble cavitation. J. Fluid Mech. 233, 633–660.10.1017/S0022112091000630CrossRefGoogle Scholar
De Chizelle, Y. K., Ceccio, S. L. & Brennen, C. E. 1995 Observations and scaling of travelling bubble cavitation. J. Fluid Mech. 293, 99–126.10.1017/S0022112095001650CrossRefGoogle Scholar
Epstein, P. S. & Plesset, M. S. 1950 On the stability of gas bubbles in liquid–gas solutions. J. Chem. Phys. 18 (11), 1505–1509.10.1063/1.1747520CrossRefGoogle Scholar
Fuller, E. N., Schettler, P. D. & Giddings, J. C. 1966 New method for prediction of binary gas-phase diffusion coefficients. Ind. Engng Chem. 58 (5), 18–27.10.1021/ie50677a007CrossRefGoogle Scholar
Gates, E. M. & Acosta, A. J. 1979 Some effects of several free stream factors on cavitation inception on axisymmetric bodies. In Proceedings 12th Symposium on Naval Hydrodynamics, Washington, DC, pp. 86–108. National Academy of Sciences.Google Scholar
George, D. L., Iyer, C. O. & Ceccio, S. L. 2000 Measurement of the bubbly flow beneath partial attached cavities using electrical impedance probes. Trans. ASME J. Fluids Engng 122 (1), 151–155.10.1115/1.483237CrossRefGoogle Scholar
Gopalan, S. & Katz, J. 2000 Flow structure and modeling issues in the closure region of attached cavitation. Phys. Fluids 12 (4), 895–911.10.1063/1.870344CrossRefGoogle Scholar
Katz, J. 1984 Cavitation phenomena within regions of flow separation. J. Fluid Mech. 140, 397–436.10.1017/S0022112084000665CrossRefGoogle Scholar
Laberteaux, K. R., Ceccio, S. L., Mastrocola, V. J. & Lowrance, J. L. 1998 High speed digital imaging of cavitating vortices. Exp. Fluids 24 (5–6), 489–498.10.1007/s003480050198CrossRefGoogle Scholar
Li, C. Y. & Ceccio, S. L. 1996 Interaction of single travelling bubbles with the boundary layer and attached cavitation. J. Fluid Mech. 322, 329–353.10.1017/S0022112096002819CrossRefGoogle Scholar
Li, J., Chen, H., Zhou, W., Wu, B., Stoyanov, S. D. & Pelan, E. G. 2014 Growth of bubbles on a solid surface in response to a pressure reduction. Langmuir 30 (15), 4223–4228.10.1021/la404658hCrossRefGoogle ScholarPubMed
Meinhart, C. D., Wereley, S. T. & Santiago, J. G. 2000 A PIV algorithm for estimating time-averaged velocity fields. Trans. ASME J. Fluids Engng 122 (2), 285–289.CrossRefGoogle Scholar
Ojha, R. P., Lemieux, P. A., Dixon, P. K., Liu, A. J. & Durian, D. J. 2004 Statistical mechanics of a gas-fluidized particle. Nature 427 (6974), 521–523.10.1038/nature02294CrossRefGoogle ScholarPubMed
Parkin, B. R. & Kermeen, R. W. 1953 Incipient cavitation and boundary layer interaction on a streamlined body. Tech Rep. California Institute of Technology.Google Scholar
Plesset, M. S. & Prosperetti, A. 1977 Bubble dynamics and cavitation. Annu. Rev. Fluid Mech. 9 (1), 145–185.10.1146/annurev.fl.09.010177.001045CrossRefGoogle Scholar
Russell, P. S., Giosio, D. R., Venning, J. A., Pearce, B. W., Brandner, P. A. & Ceccio, S. 2016 Microbubble generation from condensation and turbulent breakup of sheet cavitation. In 31st Symposium on Naval Hydrodynamics, pp. 11–16. Office of Naval Research, USA.Google Scholar
Tinevez, J., Perry, N., Schindelin, J., Hoopes, G. M., Reynolds, G. D., Laplantine, E., Bednarek, S. Y., Shorte, S. L. & Eliceiri, K. W. 2017 Trackmate: an open and extensible platform for single-particle tracking. Methods 115, 80–90.10.1016/j.ymeth.2016.09.016CrossRefGoogle ScholarPubMed
Van Wijngaarden, L. 1967 On the growth of small cavitation bubbles by convective diffusion. Intl J. Heat Mass Transfer 10 (2), 127–134.CrossRefGoogle Scholar

Ram et al. supplementary movie 1

Cavitation on Model I

Download Ram et al. supplementary movie 1(Video)
Video 35.6 MB

Ram et al. supplementary movie 2

Upstream migration of micro-bubbles and cavitation inception on Model II

Download Ram et al. supplementary movie 2(Video)
Video 48.6 MB

Ram et al. supplementary movie 3

Upstream migration of micro-bubbles and cavitation inception within the Separated Region of Model III

Download Ram et al. supplementary movie 3(Video)
Video 46.4 MB