Evaluation of Acousto-Optic Effect on Size Distribution Measurement of Oscillating Cavitation Bubbles Using Optical Spectrometer

A size distribution measurement method of the oscillating cavitation bubbles using the diffraction pattern of the bubbles has been studied by the authors. This method can measure the diameter distribution of the small oscillating bubbles. However, it has a disadvantage in that the measurement result...

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Bibliographic Details
Published inJapanese Journal of Applied Physics Vol. 51; no. 7; pp. 07GD04 - 07GD04-6
Main Authors Kuroyama, Takanobu, Ebihara, Tadashi, Mizutani, Koichi, Ohbuchi, Takeshi
Format Journal Article
LanguageEnglish
Published The Japan Society of Applied Physics 01.07.2012
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Summary:A size distribution measurement method of the oscillating cavitation bubbles using the diffraction pattern of the bubbles has been studied by the authors. This method can measure the diameter distribution of the small oscillating bubbles. However, it has a disadvantage in that the measurement result of the method is disturbed by the acousto-optic effect. In this study, the influence of the acousto-optic effect on the measurement was experimentally investigated. As a result, it was found that the diffraction pattern tended to be disturbed along the direction of the ultrasound propagation. It was also recognized that the disturbance could be reduced using the diffraction pattern along the unsusceptible direction. Consequently, it was indicated that the diameter distribution of the oscillating bubbles was correctly measured using the diffraction pattern along the unsusceptible axis by comparison with the reference value measured by the stroboscopic imaging method.
Bibliography:Typical configuration of optical spectrometer. Experimental setup. Measured light intensity distribution: (a) light intensity with cavitation bubbles and (b) ambient light intensity. Temporal waveform of the light intensity. Disturbance by the acousto-optic effect: (a) ambient light distribution and (b)--(d) peak-to-peak amplitudes for input powers of 35, 45, and 55 W, respectively. Experimental result at $\varphi=0$. (a) Diffraction pattern. Dots show the measured light intensity, the solid line shows the fitted curve calculated without the focal spot region, and the dashed line shows the fitted curve calculated with the focal spot region. (b) Diameter distributions. Bars show the diameter distribution measured by stroboscopic imaging, the solid line shows the diameter distribution calculated from the diffraction pattern without the focal spot region, and the dashed line shows the diameter distribution calculated from the diffraction pattern with the focal spot region. One-cycle fluctuation of the volume-based mean diameter. Diffraction pattern for a single bubble.
ISSN:0021-4922
1347-4065
DOI:10.1143/JJAP.51.07GD04