great! this provides a method of not only measuring and hearing
stellar seismic activity but also another method of predicting stellar
lifespan and supernovae.
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Quantitative visualization of ultrasonic acoustic waves by means of
digital laser speckle-technologies
Journal Journal of Engineering Physics and Thermophysics
Issue Volume 81, Number 2 / March, 2008
C. A. Greated1, J. A. Cosgrove2 and N. A. Fomin3
(1) University of Edinburgh, Edinburgh, Scotland, UK
(2) Professional Scientific Limited, Edinburgh Technology Transfer
Centre BioSpace, Edinburgh, Scotland, UK
(3) A. V. Luikov Heat and Mass Transfer Institute, National Academy
of Sciences of Belarus, 15 P. Brovka Str., Minsk, 220072, Belarus
Received: 25 November 2007 Published online: 9 August 2008
Abstract An original version of digital laser speckle photography has
been used for visualization and quantitative diagnosis of acoustic
waves in liquids in the megahertz frequency range. Standing acoustic
waves were generated in tanks of special configuration which permitted
obtaining analytical dependences of refraction angles of the probe
laser radiation on the wave intensity. These refraction angles were
determined experimentally by the change in contrast of the speckle
fields arising in the scattered probe radiation and recorded by means
of high-resolution digital CCD matrices. Quantitative diagnosis of the
pressure and velocity fields in acoustic waves was carried out by
measuring the deformation of the laser intensity correlation functions
in recorded speckle fields.
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