Spatial study on a multibubble system for sonochemistry by laser-light scattering
Spatial study on a multibubble system for sonochemistry by laser-light scattering
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DOI：
10.1016/j.ultsonch.2004.05.010
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发表时间：
2005-01-01
影响因子：
8.4
通讯作者：
Iida, Y
中科院分区：
文献类型：
--
作者：
Tuziuti, T;Yasui, K;Iida, Y
通过改变声传播方向上的测量位置，测量气泡散射光的强度，研究了超声驻波场中多空化气泡的体积振荡。当在空化泡中引入一个比声波波长小一半的薄光片时，在声压的波腹处，散射光强度发生振荡。的峰到峰的光强度对应于有助于声化学反应的气泡的数量，因为在压力波腹振荡气泡的半径是限制在一定范围内，由于形状的不稳定性和Bjerknes力的作用，从波腹气泡，大于共振尺寸的驱逐。实验结果表明，在靠近声源一侧测得的振荡散射光强度波形与单气泡实验中所见的波形相似。散射光波形的峰-峰光强度在靠近其中行波占主导地位的声源的一侧较低，而在靠近远离声源的水面的一侧强度相对较高，并且具有与驻波的半波长的周期性相对应的周期性结构。这些在水面附近的高强度和周期性的趋势对应于在超声驻波中的发光图像中看到的周期性发光条纹，如Hatanaka等人[Jpn. J. Appl.Phys.39（2000）2962]。本文提出的光散射方法可用于评价影响声化学反应的剧烈振荡空化泡的空间分布。(C)2004 Elsevier B. V.保留所有权利。
Volumetric oscillation of multiple cavitation bubbles in an ultrasonic standing-wave field is investigated spatially through the intensity measurements of scattered light from bubbles changing the measuring position in the direction of sound propagation. When a thin light sheet finer than half of wavelength of sound is introduced into the cavitation bubbles, at an antinode of sound pressure the scattered light intensity oscillates. The peak-to-peak light intensity corresponds to the number of the bubbles which contribute to the sonochemical reaction because the radius for oscillating bubbles at pressure antinodes is restrictive in a certain range due to the shape instability and the action of Bjerknes force that expels from the antinode bubbles that are larger than the resonant size. The experimental results show that the intensity waveform of oscillating scattered light measured at the side near the sound source is similar to the waveform as seen in a single-bubble experiment. The peak-to-peak light intensity for the scattered light waveform is low at the side near the sound source where the progressive wave is dominant, while at the side near the water surface far from the sound source the intensity is relatively high and has periodic structure corresponding to the periodicity of half wavelength from the standing wave. These tendencies of high intensity near the water surface and the periodicity correspond to the periodic luminescent stripes seen in images of luminescence in an ultrasonic standing wave as reported by Hatanaka et al. [Jpn. J. Appl. Phys. 39 (2000) 2962]. The present method of light scattering is promising for evaluating spatial distribution of violently oscillating cavitation bubbles which effect sonochemical reactions. (C) 2004 Elsevier B.V. All rights reserved.