Quantitative observations of cavitation activity in a viscoelastic medium
Quantitative observations of cavitation activity in a viscoelastic medium
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DOI：
10.1121/1.3626156
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发表时间：
2011-11-01
影响因子：
2.4
通讯作者：
Coussios, Constantin C.
中科院分区：
文献类型：
--
作者：
Collin, Jamie R. T.;Coussios, Constantin C.
目前缺乏粘弹性介质中单泡空化的定量实验观察，这将使现有模型得到验证。本研究使用1.15 MHz高强度聚焦超声换能器在琼脂凝胶中诱导单泡空化，并使用聚焦单元件被动空化检测（PCD）换能器观察。为了实现定量观测，通过使用嵌入式球形散射器和水听器的双稳态散射替代技术，对球形聚焦PCD系统进行了完整的接收校准。通过接收传递函数和琼脂凝胶的频率相关衰减来调整PCD接收的模拟压力，可以将测量的声发射与使用改进的Keller-Miksis方法对单泡空化进行数值模拟预测的声发射进行直接比较，该方法考虑了周围介质的粘弹性。在接近空化阈值的入射峰分压处，实验和数值模型均观察到周期倍增现象。通过对两组结果的比较，可以对实验观测中的平衡气泡半径进行估计，并有可能推广到材料参数的估计。这些估计值的使用使模型和实验之间有很好的一致性。(C) 2011声学，美国声学学会(DOI: 10.1121/1.3626156)
Quantitative experimental observations of single-bubble cavitation in viscoelastic media that would enable validation of existing models are presently lacking. In the present work, single bubble cavitation is induced in an agar gel using a 1.15 MHz high intensity focused ultrasound transducer, and observed using a focused single-element passive cavitation detection (PCD) transducer. To enable quantitative observations, a full receive calibration is carried out of a spherically focused PCD system by a bistatic scattering substitution technique that uses an embedded spherical scatterer and a hydrophone. Adjusting the simulated pressure received by the PCD by the transfer function on receive and the frequency-dependent attenuation of agar gel enables direct comparison of the measured acoustic emissions with those predicted by numerical modeling of single-bubble cavitation using a modified Keller-Miksis approach that accounts for viscoelasticity of the surrounding medium. At an incident peak rarefactional pressure near the cavitation threshold, period multiplying is observed in both experiment and numerical model. By comparing the two sets of results, an estimate of the equilibrium bubble radius in the experimental observations can be made, with potential for extension to material parameter estimation. Use of these estimates yields good agreement between model and experiment. (C) 2011 Acoustical,Society of America. [DOI: 10.1121/1.3626156]