Focusing Source Composed of Axisymmetrical Areas

E.Kozaczka, G.Grelowska (Technical University of Koszalin, Naval University of Gdynia, Gdynia, Poland)

e-mail: ekoz@amw.gdynia.gdynia.pl

There are different techniques available that may be used to achieve an effect of focusing of acoustic energy. One of them is based on phase shift between signals emitted by different parts of the source. The axisymmetric design of different structure has been used for this purpose. Although such type of array is known, there are comparatively little available experimental data concerning the radiation of finite amplitude wave by it. The aim of the paper is to present results of examination, both experimental and numerical, of the pressure field of the arrays composed of axisymmetric areas of different structure radiating the finite amplitude wave.  The sources are constructed from piezoelectric elements of a resonant frequency equal to 1.5 MHz. Applying the layer adjusting the PZT transducers to water allow to broad the band of the frequencies of radiated wave up to range 1.2 MHz - 1.8 MHz.  The measurements were conducted for various frequencies and for pressure values near the radiating surface within the range of 20 - 150 kPa. The experimental data have been compared with the results of the numerical research carried out with the use of a model constructed on the basis of the KZK equation. Results of experimental and theoretical investigation of finite wave propagation from axisymetric array complete data on structure of pressure field of finite amplitude focusing sources.


Section : 1