Skip to main content
×
Home
    • Aa
    • Aa

The acceleration of solid particles subjected to cavitation nucleation

  • BRAM M. BORKENT (a1), MANISH ARORA (a1), CLAUS-DIETER OHL (a1) (a2), NICO DE JONG (a1), MICHEL VERSLUIS (a1), DETLEF LOHSE (a1), KNUD AAGE MØRCH (a3), EVERT KLASEBOER (a4) and BOO CHEONG KHOO (a5)...
Abstract

The cavity–particle dynamics at cavitation inception on the surface of spherical particles suspended in water and exposed to a strong tensile stress wave is experimentally studied with high-speed photography. Particles, which serve as nucleation sites for cavitation bubbles, are set into a fast translatory motion during the explosive growth of the cavity. They reach velocities of ~40 ms−1 and even higher. When the volume growth of the cavity slows down, the particle detaches from the cavity through a process of neck-breaking, and the particle is shot away. The experimental observations are simulated with (i) a spherical cavity model and (ii) with an axisymmetric boundary element method (BEM). The input for both models is a pressure pulse, which is obtained from the observed radial cavity dynamics during an individual experiment. The model then allows us to calculate the resulting particle trajectory. The cavity shapes obtained from the BEM calculations compare well with the photographs until neck formation occurs. In several cases we observed inception at two or more locations on a single particle. Moreover, after collapse of the primary cavity, a second inception was often observed. Finally, an example is presented to demonstrate the potential application of the cavity–particle system as a particle cannon, e.g. in the context of drug delivery into tissue.

Copyright
Linked references
Hide All

This list contains references from the content that can be linked to their source. For a full set of references and notes please see the PDF or HTML where available.

J. L. Green , D. J. Durben , G. H. Wolf & C. A. Angell 1990 Water and solutions at negative pressure: Raman spectroscopy study to −80 megapascals. Science 249, 649652.

S. I. Madanshetty 1995 A conceptual model for acoustic microcavitation. J. Acoust. Soc. Am. 98, 26812689.

H. Marschall , K. A. Mørch , A. P. Keller & M. Kjeldsen 2003 Cavitation inception by almost spherical solid particles in water. Phys. Fluids 15, 545553.

A. Zijlstra & C. D. Ohl 2008 On fiber optic probe hydrophone measurements in a cavitating liquid. J. Acoust. Soc. Am. 123, 2932.

Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Fluid Mechanics
  • ISSN: 0022-1120
  • EISSN: 1469-7645
  • URL: /core/journals/journal-of-fluid-mechanics
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×
MathJax

Keywords:

Type Description Title
VIDEO
Movies

Borkent et al. supplementary movie
Movie 3. Particle injection into gelatin induced by cavitation, see figure 13. The water-gelatin interface is in the centre of the frames; a particle of radius ~50 μm is initially located in the water, touching the gelatin. This particle holds a cavitation nucleus that explodes, and it is shot into the gelatin. A second particle (radius about 40 μm) is accelerated from some distance and under an angle from below and also penetrates into the gelatin. The upper particle stays entrained after the cavitation activity has ceased whereas the lower particle is repelled from the elastic material. The number at the upper left states the time in microseconds.

 Video (646 KB)
646 KB
VIDEO
Movies

Borkent et al. supplementary movie
Movie 1. Example of a cavitation event on a particle and the successive dynamics, see figure 3. Initially an isolated particle is visible. A cavitation bubble expanding on the left side of the particle becomes visible and grows explosively. As the growth decelerates the particle moves away from the cavity and forms a neck which breaks. During the detachment process the cavity develops a mushroom shape, and collapses. Moreover, the volume centre of the cavity shifts slightly to the left. The re-expanding cavity obtains a funnel-like shape, which indicates that a liquid jet has developed during the cavity collapse. Then a second attached cavity on the particle becomes visible and grows in the following frames into a void of size comparable to that of the particle. Two additional out-of-focus cavitation events are recorded in this series, too. They are visible as blurry shadows in the upper right corner and the second cavitation event leads to a dark fuzzy object just below the in-focus cavity. The movie is taken at approximately 1 million frames/s. The number at the upper left states the time in microseconds.

 Video (908 KB)
908 KB
VIDEO
Movies

Borkent et al. supplementary movie
Movie 2. Experiment demonstrating that a particle being exposed twice to a shock wave can nucleate a cavitation bubble on its surface in both events, see figure 5. Here, a tensile stress wave excites cavitation at t=0 and at t=200 μs. The trajectory of the particle is indicated in the last frame (t=451 μs) with the dashed black line. Note the different directions of motion set up at the successive cavitation events. The frame rate of the movie is 220.000 frames/s. The number at the upper left states the time in microseconds.

 Video (1.7 MB)
1.7 MB

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 46 *
Loading metrics...

Abstract views

Total abstract views: 118 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 27th March 2017. This data will be updated every 24 hours.