Marine Physical Laboratory, Scripps Institution of Oceanography, La Jolla, California 92093-0238, USA.
J Acoust Soc Am. 2011 Jan;129(1):74-84. doi: 10.1121/1.3514416.
Understanding the formation and evolution of bubble populations is important in a wide range of situations, including industrial processes, medical applications, and ocean science. Passive acoustical techniques can be used to track changes in the population, since each bubble formation or fragmentation event is likely to produce sound. This sound potentially contains a wealth of information about the fragmentation process and the products, but to fully exploit these data it is necessary to understand the physical processes that determine its characteristics. The focus of this paper is binary fragmentation, when turbulence causes one bubble to split into two. Specifically, the effect that bubble-bubble coupling has on the sound produced is examined. A numerical simulation of the acoustical excitation of fragmenting bubbles is used to generate model acoustic signals, which are compared with experimental data. A frequency range with a suppressed acoustic output which is observed in the experimental data can be explained when coupling is taken into account. In addition, although the driving mechanism of neck collapse is always consistent with the data for the larger bubble of the newly formed pair, a different mechanism must be driving the smaller bubble in some situations.
理解气泡群的形成和演化在广泛的情况下都很重要，包括工业过程、医疗应用和海洋科学。被动声学技术可用于跟踪种群的变化，因为每个气泡的形成或破碎事件都可能产生声音。这种声音可能包含关于破碎过程和产物的大量信息，但要充分利用这些数据，就必须了解决定其特征的物理过程。本文的重点是二元破碎，即当湍流导致一个气泡分裂成两个时。具体来说，研究了气泡-气泡耦合对产生声音的影响。使用破碎气泡的声学激励数值模拟来产生模型声学信号，并将其与实验数据进行比较。当考虑耦合时，可以解释在实验数据中观察到的在一个受抑制的声学输出频率范围内。此外，尽管颈部坍塌的驱动机制始终与新形成的对中大气泡的数据一致，但在某些情况下，小气泡的驱动机制必须不同。
