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A study of the collapse of arrays of cavities

Published online by Cambridge University Press:  21 April 2006

J. P. Dear
Affiliation:
Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE, UK
J. E. Field
Affiliation:
Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE, UK

Abstract

This paper describes a method for examining the collapse of arrays of cavities using high-speed photography and the results show a variety of different collapse mechanisms. A two-dimensional impact geometry is used to enable processes occurring inside the cavities such as jet motion, as well as the movement of the liquid around the cavities, to be observed. The cavity arrangements are produced by first casting water/gelatine sheets and then forming circular holes, or other desired shapes, in the gelatine layer. The gelatine layer is placed between two thick glass blocks and the array of cavities is then collapsed by a shock wave, visualized using schlieren photography and produced from an impacting projectile. A major advantage of the technique is that cavity size, shape, spacing and number can be accurately controlled. Furthermore, the shape of the shock wave and also its orientation relative to the cavities can be varied. The results are compared with proposed interaction mechanisms for the collapse of pairs of cavities, rows of cavities and clusters of cavities. Shocks of kbar (0.1 GPa) strength produced jets of c. 400 m s−1 velocity in millimetre-sized cavities. In closely-spaced cavities multiple jets were observed. With cavity clusters, the collapse proceeded step by step with pressure waves from one collapsed row then collapsing the next row of cavities. With some geometries this leads to pressure amplification. Jet production by the shock collapse of cavities is suggested as a major mechanism for cavitation damage.

Type
Research Article
Copyright
© 1988 Cambridge University Press

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References

Avellan, F. & Karimi, A. 1987 Dynamics of vortex cavitation involved in the erosion of hydraulic machines. Proc. 7th Intl Conf. on Erosion by Liquid and Solid Impact (ed. J. E. Field & J. P. Dear), Cavendish Lab., Cambridge, UK, paper 25.
Benjamin, T. P. & Ellis, A. T. 1966 The collapse of cavitation bubbles and the pressures thereby produced against solid boundaries. Phil. Trans. R. Soc. Lond. A 260, 221240.Google Scholar
Bowden, F. P. & Yoffe, A. D. 1952 Initiation and Growth of Explosion in Liquids and Solids. Reprinted 1985. Cambridge University Press.
Bowden, F. P. & Yoffe, A. D. 1958 Fast Reactions in Solids. Butterworths.
Brunton, J. H. 1967 Erosion by liquid shock. Proc. 2nd Intl Conf. on Rain Erosion (ed. A. A. Fyall & R. B. King), Royal Aircraft Establishment, UK, p. 291.
Chaudhri, M. M., Almgreu, L-A. & Perrson, A. 1982 High-speed photography of the interactions of shocks with voids in condensed media. Proc. 15th Intl Conf. on High Speed Photography and Phototonics, SPIE, vol. 348, p. 388.
Chaudhri, M. M. & Field, J. E. 1974 The role of rapidly compressed pockets in the initiation of condensed explosives. Proc. R. Soc. Lond. A 340, 113128.Google Scholar
Dear, J. P. 1985 The fluid mechanics of liquid/solid impact. PhD thesis, University of Cambridge.
Dear, J. P. & Field, J. E. 1988 High-speed photography of surface geometry effects in liquid/solid impact. J. Appl. Phys. (In Press).Google Scholar
Dear, J. P., Field, J. E. & Swallowe, G. M. 1984 High-speed photographic studies of liquid/solid and cavity collapse using two-dimensional gelatine configurations. Proc. 16th Intl Conf. on High-speed Photography, Strasbourg, pp. 568575.
Dear, J. P., Field, J. E. & Walton, A. H. 1988 Gas compression, light emission and jet formation in cavities collapsed by a shock wave. Nature (In Press).Google Scholar
Ellis, A. T. 1966 On jets and shock waves in cavitation. Proc. 6th Symp. on Naval Hydrodyn., Washington DC, pp. 137161.
Field, J. E., Dear, J. P., Davies, P. N. H. & Finnström, M. 1983 An investigation of the shock structures and the conditions for jetting during liquid impact. Proc. 6th Intl Conf. on Erosion by Liquid and Solid Impact (ed. J. E. Field & N. S. Corney), Cavendish Lab., Cambridge, UK, paper 19.
Field, J. E., Lesser, M. B. & Dear, J. P. 1985 Studies of two-dimensional liquid-wedge impact and their relevance to liquid-drop impact problems. Proc. R. Soc. Lond. A 401, 225.Google Scholar
Fujikawa, S. & Akamatsu, T. 1980 Effects of the non-equilibrium condensation of vapour on the pressure wave produced by the collapse of a bubble in a liquid. J. Fluid Mech. 97, 481512.Google Scholar
Grant, M. McD. & Lush, P. A. 1987 Liquid impact on a bilinear elastic–plastic solid and its role in cavitation erosion. J. Fluid Mech. 176, 237252.Google Scholar
Hansson, I. & Mørch, K. A. 1980 The dynamics of cavity clusters in ultrasonic (vibratory) cavitation erosion. J. Appl. Phys. 51, 4651.Google Scholar
Hansson, I., Kendrinskii, V. & Mørch, K. A. 1982 On the dynamics of cavity clusters. J. Phys. D: Appl. Phys. 15, 1725.Google Scholar
Hickling, R. & Plesset, M. S. 1964 Collapse and rebound of a spherical bubble in water. Phys. Fluids 7, 714.Google Scholar
Kling, C. L. & Hammitt, F. G. 1972 A photographic study of spark-induced cavitation bubble collapse. Trans. ASME D: J. Basic Engng 94, 825833.Google Scholar
Kornfeld, M. & Suvorov, L. 1944 On the destructive action of cavitation. J. Appl. Phys. 15, 495.Google Scholar
Lauterborn, W. 1979 Liquid jets from cavitation bubble collapse. Proc. 5th Intl Conf. on Erosion by Liquid and Solid Impact (ed. J. E. Field), Cavendish Lab., Cambridge, UK, paper 58.
Lauterborn, W. & Bolle, H. 1975 Experimental investigation of cavitation bubble collapse in neighbourhood of a solid boundary. J. Fluid Mech. 72, 391399.Google Scholar
Mader, C. L. 1965 Initiation of detonation by the interaction of shocks with density discontinuities. Phys. Fluids 8, 18111816.Google Scholar
Mader, C. L. 1979 Numerical Modelling of Detonators. Berkeley: University of California Press.
Mader, C. L. 1985 The three-dimensional hydrodynamic hot-spot model. Proc. 8th Intl Symp. on Detonation, Albuquerque, New Mexico, preprint 366–374.
Mitchell, T. M. & Hammitt, F. G. 1973 Asymmetric cavitation bubble collapse. Trans. ASME D: J. Basic Engng 95, 2937.Google Scholar
Mørch, K. A. 1979 Dynamics of cavitation bubbles and cavitation liquids, in Erosion (ed. C. M. Preece), pp. 309353. Academic.
Naude, C. F. & Ellis, A. T. 1961 On the mechanism of cavitation damage by non-hemispherical cavities collapsing in contact with a solid boundary. Trans. ASME D: J. Basic Engng 83, 648656.Google Scholar
Plesset, M. S. 1964 Bubble dynamics, in Cavitation in Real Liquids (ed. R. Davies), pp. 118. Elsevier.
Plesset, M. S. & Chapman, R. B. 1971 Collapse of an initially spherical vapour cavity in the neighbourhood of a solid boundary. J. Fluid Mech. 47, 283.Google Scholar
Plesset, M. S. & Prosperetti, A. 1971 Bubble dynamics and cavitation. Ann. Rev. Fluid Mech. 9, 145.Google Scholar
Rayleigh, Lord 1917 On the pressure developed in a liquid during the collapse of a spherical cavity. Phil. Mag. 34, 9498.Google Scholar
Schutler, N. D. & Mesler, R. B. 1965 A photographic study of the dynamics and damage capabilities of bubbles collapsing near solid boundaries. Trans. ASME D: J. Basic Engng 87, 648656.Google Scholar
Shima, A. & Nakajima, K. 1977 The collapse of a non-hemispherical bubble attached to a solid wall. J. Fluid Mech. 80, 369391.Google Scholar
Tomita, Y. & Shima, A. 1986 Mechanisms of impulsive pressure generation and damage pit formation by bubble collapse. J. Fluid Mech. 169, 535564.Google Scholar
Tomita, Y., Shima, A. & Ohno, T. 1984 Collapse of multiple gas bubbles by a shock and induced impulsive pressure. J. Appl. Phys. 56, 125.Google Scholar
Tulin, M. P. 1969 On the creation of ultra-jets, in L. I. Sedov 60th Anniversary Volume: Problems of Hydrodynamics and Continuum Mechanics, Soc. For Ind. and Appl. Maths, Philadelphia, pp. 725747.
Vyas, B. & Preece, C. M. 1976 Stress produced in a solid by cavitation. J. Appl. Phys. 47, 51335138.Google Scholar