Wu Pengfei, Bai Lixin, Lin Weijun, Yan Jiuchun
State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China.
Ultrason Sonochem. 2017 Sep;38:75-83. doi: 10.1016/j.ultsonch.2017.03.002. Epub 2017 Mar 6.
The inception and evolution of acoustic cavitation structures in thin liquid layers under different conditions and perturbations are investigated experimentally with high speed photography. The stability and characterization of cavitation structures are quantified by image analysis methods. It is found that cavitation structures (shape of bubble cloud and number of bubbles) are stable under unaltered experimental conditions, and the cavitation bubble cloud will return to the original structure and remain stable even in the face of large perturbations. When the experimental conditions are altered (for example, acoustic intensity, cavitation nuclei, boundary), the cavitation structures will vary correspondingly. Further analysis implies that the stability of cavitation structures is closely related to the number of bubbles in the cavitation bubble cloud. There are two mechanisms acting simultaneously in the cavitation bubble cloud evolution, one "bubble production" and the other "bubble disappearance". We propose that the two mechanisms acting together constitute the most likely explanation for the stability of cavitation structures and their transformation.
利用高速摄影技术对不同条件和扰动下薄液层中声空化结构的产生与演化进行了实验研究。通过图像分析方法对空化结构的稳定性和特征进行了量化。研究发现，在未改变的实验条件下，空化结构（气泡云形状和气泡数量）是稳定的，即使面对较大扰动，空化气泡云也会恢复到原始结构并保持稳定。当实验条件改变时（例如，声强、空化核、边界），空化结构会相应变化。进一步分析表明，空化结构的稳定性与空化气泡云中的气泡数量密切相关。在空化气泡云演化过程中，有两种机制同时起作用，一种是“气泡产生”，另一种是“气泡消失”。我们认为，这两种机制共同作用最有可能解释空化结构的稳定性及其转变。
