Yu.I. Kabarukhin PARAMETRIC SOUND SOURCE WITH A LAYER OF BOUNDARY BUBBLES

The results of experimental studies of a parametric sound source with layers of boundary bubbles in a self-detection mode are presented. It has been shown that maximum effectiveness of transformation of spectral components energy for modulated pump wave into energy of self-detected wide-band acoustic radiation is realized in the bubbles being formed on current-conducting sound conducting plates, the thickness of which is much less than the one-forth of the pump wavelength within the material of the plate. In [1,2] it has been shown that if a thin layer of gas bubbles is exposed to radiation of a biharmonic pump wave, sine radiation of resonant frequency is formed on the area of the layer exposed to sound. If the layer of floating bubbles is exposed to radiation of generally modulated wave, then detection of pump wave takes place, as a result of which video impulse acoustic signals are formed. The detection of acoustic signals in thin layer of floating bubbles has been theoretically and experimentally studied in [3]. The possibility to increase effectiveness of transformation of modulated pump wave spectral components energy into energy of wide-band low-frequency acoustic signals while preserving high directivity of parametric radiation has been shown. The possibility to increase by 30 dB or even more the sound pressure level of self-detecte