QUANTITATIVE VISUALIZATION OF ULTRASONIC ACOUSTIC WAVES BY MEANS OF DIGITAL LASER SPECKLE-TECHNOLOGIES
C. A. Greated,a J. A. Cosgrove,b and N. A. Fominc UDC 535.241.13:534 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. aUniversity of Edinburgh, Edinburgh, Scotland, UK; bProfessional Scientific Limited, Edinburgh Technology Transfer Centre BioSpace, Edinburgh, Scotland, UK; cA. V. Luikov Heat and Mass Transfer Institute, National Academy of Sciences of Belarus, 15 P. Brovka Str., Minsk, 220072; email: fomin@hmti.ac.by. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 81, No. 2, pp. 229-239, March-April, 2008. Original article submitted November 25, 2007.