Acoustic power dependences of sonoluminescence and bubble dynamics

作者：Lee Hyang Bok; Choi Pak Kon^*

来源：Ultrasonics Sonochemistry, 2014, 21(6): 2037-2043.

DOI：10.1016/j.ultsonch.2014.02.008

• Sonoluminescence
• Sonochemiluminescence
• Bubble streamer
• Bubble cluster
• High-speed photography
• Acoustic emission

The decreasing effect of sonoluminescence (SL) in water at high acoustic powers was investigated in relation to bubble dynamics and acoustic emission spectra. The intensity of SL was measured in the power range of 1-18W at 83.8 kHz for open-end (free liquid surface and film-covered surface) and fixed-end boundaries of sound fields. The power dependence of the SL intensity showed a maximum and then decrease to zero for all the boundaries. Similar results were obtained for sonochemiluminescence in luminol solution. The power dependence of the SL intensity was strongly correlated with the bubble dynamics captured by high-speed photography at 64k fps. In the low-power range where the SL intensity increases, bubble streamers were observed and the population of streaming bubbles increased with the power. At powers after SL maximum occurred, bubble clusters came into existence. Upon complete SL reduction, only bubble clusters were observed. The subharmonic in the acoustic emission spectra increased markedly in the region where bubble clusters were observed. Nonspherical oscillations of clustering bubbles may make a major contribution to the subharmonic.

• 出版日期2014-11