Observations have been made of the growth and collapse of surface and cloud cavitation on a finite aspect ratio hydrofoil oscillating in pitch. The cavitation was recorded using both still and high-speed motion picture photography, and the variations with cavitation number and reduced frequency of oscillation were investigated. The noise generated by the cavity collapse was also measured and an...

A passive cavitation detector (PCD) identifies cavitation events by sensing acoustic emissions generated by the collapse of bubbles. In this work, a dual passive cavitation detector (dual PCD), consisting of a pair of orthogonal confocal receivers, is described for use in shock wave lithotripsy. Cavitation events are detected by both receivers and can be localized to within 5 mm by the nature o...

Laser-induced bubbles can be caused by an optical breakdown in water. They are a result of the optodynamical process where the energy of a high intensity laser pulse is converted into the mechanical energy through an optodynamic conversion. At this process the absorbed optical energy causes plasma expansion that in turn initiates dynamic phenomena: spreading of a shock wave and the development ...

We report a novel form of xylem dysfunction in angiosperms: reversible collapse of the xylem conduits of the smallest vein orders that demarcate and intrusively irrigate the areoles of red oak (Quercus rubra) leaves. Cryo-scanning electron microscopy revealed gradual increases in collapse from approximately -2 MPa down to -3 MPa, saturating thereafter (to -4 MPa). Over this range, cavitation re...

Abstract: An experimental study is carried out in a cavitation tunnel on a propeller operating downstream of a non-uniform wake. The goal of this work is to establish quantitative correlations between the near pressure field and the cavitation pattern that takes place on the propeller blades. The pressure field is measured at the walls of the test section and in the near wake of the propeller, ...

We report a novel form of xylem dysfunction in angiosperms: reversible collapse of the xylem conduits of the smallest vein orders that demarcate and intrusively irrigate the areoles of red oak (Quercus rubra) leaves. Cryo-scanning electron microscopy revealed gradual increases in collapse from approximately 22 MPa down to 23 MPa, saturating thereafter (to 24 MPa). Over this range, cavitation re...

in this paper, a new non-contact ultrasonic abrasive finishing mechanism is designed and fabricated. this mechanism combines the function of ultrasonic vibrations and the magnetic abrasive finishing (maf) process. a permanent magnet which is mounted on a horn has been used as the processing tool. this polishing tool is vibrated at an ultrasonic frequency with piezo-electric actuators. ultrasoni...

In the therapeutic ultrasound field, the cavitation frequently forms a bubble cloud that consists of many microbubbles. A method to control the violent collapse of cloud cavitation is being developed. It is comprised of two frequency ultrasound. The first is a higher frequency ultrasound waveform that makes cloud cavitation at the surface of the object. The second is a lower frequency waveform ...

This paper presents the details of the collapse process for single bubbles generated in travelling bubble cavitation around two axisymmetric headforms. The details of the bubble collapse process have been examined acoustically to understand the phenomena of rebounding and multipeaking. We find that both rebounding and multipeaking increased with reduction in the cavitation number for the ITTC h...