Picture of neon light reading 'Open'

Discover open research at Strathprints as part of International Open Access Week!

23-29 October 2017 is International Open Access Week. The Strathprints institutional repository is a digital archive of Open Access research outputs, all produced by University of Strathclyde researchers.

Explore recent world leading Open Access research content this Open Access Week from across Strathclyde's many research active faculties: Engineering, Science, Humanities, Arts & Social Sciences and Strathclyde Business School.

Explore all Strathclyde Open Access research outputs...

Generation of high power ultrasound by spark discharges in water

Mackersie, J.W. and Timoshkin, I. and MacGregor, S.J. (2005) Generation of high power ultrasound by spark discharges in water. IEEE Transactions on Plasma Science, 33 (5). pp. 1715-1724. ISSN 0093-3813

Full text not available in this repository. Request a copy from the Strathclyde author

Abstract

It is impractical to achieve the desired combination of power and bandwidth from conventional electromechanical acoustic sources. However, these characteristics can be achieved by the use of pulsed power technology to generate high-power ultrasound (HPU). High-voltage pulses induce the electrical breakdown of water and the resulting bubble formation and collapse produce acoustic waves of high power and frequency. The dynamics of spark generated bubbles are formulated to predict the development of the bubble radius with time and an experimental system to produce a consistent source of spherically symmetric HPU acoustic waves is described. Pressure pulses due to both bubble formation and collapse were detected and, although their relative amplitudes varied, their frequency spectra did not differ significantly. The amplitude of the acoustic output rises sharply for applied pulse energies up to /spl sim/25 J but the effect saturates indicating little gain and poor efficiency by using high-energy pulses. Variation of the source topology in the form of the electrode separation was found to be the most important factor in the acoustic output. The detected HPU increased as the source became larger but as the two-thirds power of the electrode separation, thereby showing progressively diminishing enhancement. The frequency content of the acoustic signal did not appear to vary with either applied pulse energy or the electrode separation.