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Pressure fluctuations and their effect on cavitation inception within water jets

Published online by Cambridge University Press:  26 April 2006

Bing Ran  and
Joseph Katz
Bing Ran
Affiliation:
Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
Joseph Katz
Affiliation:
Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
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Abstract

Instantaneous and phase averaged pressure distributions in the near field of a jet, and their effects on the conditions for the onset of cavitation are studied in detail. The measurements are performed by using microscopic bubbles as pressure sensors, and holography as a means of detecting them. Experiments are performed at Red exceeding 4 × 105, with and without acoustic excitation. The results show that the highest negative pressure peaks (–0.97) and the resulting cavitation inception occur because of vortex pairing. Prior to pairing the negative peaks are between –0.8 and –0.9. Weak acoustic excitation changes the entire flow structure and the spatial distributions of bubbles, but has little effect on the onset of cavitation. Downstream of the potential core the highest pressure peaks (∼ –0.6) are considerably smaller, in agreement with the occurrence of cavitation there. It is also shown that although the r.m.s. values of pressure fluctuations do not vary with the jet speed, the probability distribution changes significantly, causing a reduction in the inception index with increasing velocity. The probability of cavitation inception is estimated from the distributions of bubbles and pressure peaks. It is shown that the actual, non-uniform bubble distribution increases the probability of inception owning to migration of the bubbles to the low pressure regions.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 262 , 3 October 1994 , pp. 223 - 263
Copyright
© 1994 Cambridge University Press

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References

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 12th Symp. on Naval Hydrodynamics, Washington DC, pp. 327–339.
Ball, J. W. 1960 Discussion to Reference 75. Trans. ASME I: J. Fluids Engng 84 (1), 6–11.Google Scholar
Baker, C. B., Holl, J. W. & Arndt, R. E. A. 1975 The influence of gas content and polyethylene oxide additive upon conf.ned jet cavitation in water. TM 75-274. Applied Research Laboratory, Pennsylvania State University.
Barefoot, G. L. 1972 Fluctuating pressure characteristics in the mixing region of a perturbed and unperturbed round free jet. TM 72-165. Applied Research Laboratory, Pennsylvania State University.
Billet, M. L. 1985 Cavitation nuclei measurements – a review. ASME Cavitation and Multiphase Flow Forum, Albuquerque, NM. FED vol. 23, pp. 31–38.
Ceccio, S. L. & Brennen, C. E. 1991 Observations of the dynamics and acoustics of travelling bubble cavitation. J. Fluid Mech. 223, 633–660.Google Scholar
Collier, R. J., Burkhardt, C. B. & Lin, L. H. 1970 Optical Holography. Academic.
Fuchs, H. V. 1972 Measurements of pressure fluctuations within subsonic turbulent jets. J. Sound Vib. 22 (1), 361–378.Google Scholar
George, W. K., Beuther, P. D. & Arndt, R. E. 1984 Pressure spectra in turbulent free shear flows. J. Fluid Mech. 148, 155–191.Google Scholar
Green, S. I. 1988 Tip vortex - single phase and cavitating flow phenomena. PhD thesis (Eng. 183-17), California Institute of Technology.
Ho, C. M. & Huerre, P. 1984 Perturbed free shear layers. Ann. Rev. Fluid Mech. 16, 365–424.Google Scholar
Hussain, A. K. M. F. 1986 Coherent structure and turbulence. J. Fluid Mech. 173, 303–356.Google Scholar
Hussain, A. K. M. F. & Zaman, K. M. B. 1980 Vortex pairing in a circular jet under controlled excitation. Part 2. Coherent structure dynamics. J. Fluid Mech. 101, 39–71.Google Scholar
Hussain, A. K. M. F. & Zaman, K. M. B. 1981 The preferred mode of an axisymmetric jet. J. Fluid Mech. 110, 39–71.Google Scholar
Hussain, A. K. M. F. & Zedan, M. F. 1978 Effects of the initial condition on the axisymmetric free shear layer: effects of the initial momentum thickness. Phys. Fluid 21, July, 1100–1112.Google Scholar
Johnson, V. E., Chahine, G. L., Lindenmuth, W. T., Conn, A. F., Frederick, G. S. & Giacchino, G. J. 1982 Cavitating and structured jets for mechanical bits to increase drilling rate. ASME paper no. 82-Pet-13, Energy Sources Technology Conference and Exhibition. March 7–10, New Orleans, LA.
Jorgensen, D. W. 1961 Noise from cavitating submerged water jets. J. Acoust. Soc. Am. 33, 1334–1338.Google Scholar
Katz, J. 1984 Cavitation phenomena within regions of flow separation. J. Fluid Mech. 140, 497–536.Google Scholar
Katz, J. & O'Hern, T. J. 1986 Cavitation in large scale shear flows. Trans ASME I: J. Fluids Engng 108, 373–376.Google Scholar
Kermeen, R. W. & Parkin, B. R. 1957 Incipient cavitation and wake flow behind sharp-edged disks. Cal. Inst. Tech., Hydrodyn. Lab. Rep. 85-4.
Kobayashi, R. 1967 Effect of cavitation on the discharge coefficient of standard flow nozzles. Trans. ASME D: J. Basic Engng 89 (3), 677–685.Google Scholar
Lienhard, J. H. & Goss, C. D. 1971 Influence of size and configuration on cavitation in submerged orifice flow. ASME Paper 1-FE-39.
Lienhard, J. H. & Stephenson, J. M. 1966 Temperature and scale effects upon cavitation and flashing in free and submerged jets. Trans. ASME D: J. Basic Engng 88, 525–532.Google Scholar
Lin, H. J. & Katz, J. 1988 Occurrence of cavitation in water jets. Liquid Metal Flow: MHD and Application, Progress in Astronautics and Aeronautics, vol. 111, pp. 585–604.Google Scholar
Meyer, R. S., Billet, M. L. & Holl, J. W. 1992 Freesteam nuclei and traveling-bubble cavitation. Trans. ASME I: J. Fluids Engng 114 (4), 672–679.Google Scholar
Numachi, F., Yamabe, M. & Oba, R. 1960 Cavitation effect on the discharge coefficient of the sharp-edged orifice plate. Trans. ASME D: J. Basic Engng 84 (1), pp. 1–6.Google Scholar
O'Hern, T. J. 1987 Cavitation inception scale effects: I. nuclei distributions in natural waters; II. cavitation inception in turbulent shear flow. PhD thesis (Eng. 183–15), California Institute of Technology.
Ooi, K. K. 1981 Scale effects on cavitation inception in submerged jets. PhD thesis (183–6), California Institute of Technology.
Ooi, K. K. & Acosta, A. J. 1983 The utilization of specially tailored air bubbles as static pressure sensors in a jet. Trans. ASME I: J. Fluids Engng 106 (4), 459–465.Google Scholar
Pauchet, J., Retailleau, A. & Woillez, J. 1992 The prediction of cavitation inception in turbulent water jets. In ASME Cavitation and Multiphase Flow Forum, FED vol. 135, pp. 149–158.
Plesset, M. S. & Prosperetti, A. P. 1977 Bubble dynamics and cavitation. Ann. Rev. Fluid Mech. 9, 145–185.Google Scholar
Ramani, D. & Chahine, G. L. 1992 Analytical study of a gas bubble in the flow field of a line vortex. In ASME Cavitation and Multiphase Flow Forum, FED vol. 135, pp. 69–76.
Ran, B. & Katz, J. 1991 The response of microscopic bubbles to sudden changes in ambient pressure. J. Fluid Mech. 111, pp. 585–604.Google Scholar
Saffman, P. G. 1992 Vortex Dynamics. Cambridge University Press.
Sridhar, G. & Katz, J. 1991 Implementation of particle image velocimetry to multi-phase flows. In ASME Cavitation and Multiphase Flow Forum, FED vol. 109, pp. 204–209.
Willmarth, W. W. 1975 Pressure fluctuations beneath turbulent boundary layers. Ann. Rev. Fluid Mech. 7, 13–38.Google Scholar
Zaman, K. M. B. & Hussain, A. K. M. F. 1980 Vortex pairing in circular jet under controlled excitation. J. Fluid Mech. 101, 449–491.Google Scholar