The stability of a bubble in a weakly viscous liquid subject to an acoustic traveling wave
The stability of a bubble in a weakly viscous liquid subject to an acoustic traveling wave
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DOI：
10.1063/1.3076932
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发表时间：
2009-02
影响因子：
4.6
通讯作者：
S. Shaw
中科院分区：
文献类型：
--
作者：
S. Shaw
考虑了声行波中气泡的体积振荡、平移和轴对称变形。假设气泡的平移和变形是小的，但放置没有限制的体积振荡，瑞利耗散函数和扰动分析的组合来考虑粘性的影响，在没有涡量的情况下，在三阶的小相互作用项。从声场的贡献也被确定为这个顺序，而自由振荡项是从先前导出的模型正确的分析相同的顺序。为了研究大振幅的声强迫，适当的压缩性条款唯象地添加到体积脉动方程。给出了驱动压力随驱动频率和驱动压力随平衡气泡半径变化的稳定性图。一个主要的结果是微米大小的气泡在超声制度驱动，但在千赫范围内的频率驱动的较大的气泡的行为也被认为是。在所有情况下，气泡驱动高于其各自的体积振荡的自然频率是显着更稳定的声学驱动振幅，与以前的观察结果一致。在这些相应的固有频率值以下，稳定性/不稳定性锋显示出复杂得多的结构。考虑形状模式粘性阻尼会导致气泡稳定性的普遍增加，以及稳定性/不稳定性前沿复杂性的降低。在微米尺寸的气泡的情况下，这种稳定是显着更显着的气泡驱动的固有频率以上的相应的体积模式振荡;驱动在千赫范围内的较大的气泡，形状模式阻尼的影响是不太显着的。
The volume oscillations, translation, and axisymmetric deformation of a bubble in an acoustic traveling wave are considered. Assuming the bubble translation and deformation is small, but placing no restriction on the volume oscillations, a combination of the Rayleigh dissipation function and perturbation analysis is employed to account for the effects of viscosity in the absence of vorticity to third order in the small interaction terms. Contributions from the acoustic field are also determined to this order, while the free oscillation terms are drawn from a previously derived model correct to the same order of analysis. To permit the study of large amplitude acoustic forcing, appropriate compressibility terms are phenomenologically added to the volume pulsation equation. Stability maps of driving pressure versus driving frequency and driving pressure versus the equilibrium bubble radius are presented. A predominant number of results are for micron-sized bubbles driven in the ultrasonic regime, but the behavior of larger bubbles driven at frequencies in the kilohertz range is also considered. In all cases, bubbles driven above the natural frequency of their respective volume oscillations are markedly more stable with regard to the acoustic driving amplitude, consistent with previous observations. Below these respective natural frequency values, the stability/instability fronts display a much more complex structure. Accounting for shape mode viscous damping causes a general increase in bubble stability, together with a reduction in the stability/instability front complexity. In the case of micron-sized bubbles this stabilization is markedly more significant for bubbles driven above the natural frequency of the respective volume mode oscillations; for larger bubbles driven in the kilohertz range, the influence of shape mode damping is less significant.