Contributions to the acoustic excitation of bubbles released from a nozzle.
Contributions to the acoustic excitation of bubbles released from a nozzle.
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对从喷嘴释放的气泡的声学激励的贡献。
DOI：
10.1121/1.3484087
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
G. Deane
中科院分区：
文献类型：
--
作者：
H. Czerski;G. Deane
最近已经证明，从喷嘴释放的气泡通过在气泡分离的时刻形成的空气颈部的塌陷而被激发成体积模式振荡。这些呼吸模式振荡引起了声音脉冲，而空气夹带流的声音是由许多气泡产生时发出的脉冲组成的。本文是对JASA-EL论文的详细阐述，该论文研究了从喷嘴释放的气泡的声激励。在这里，进一步的细节，在气泡形成的时刻形成的空气的颈部的崩溃和它的影响，由新形成的气泡的声音发射。使用高速摄影研究了流体表面张力的作用，发现与颈部塌陷的简单模型一致。一个再入流体射流内的气泡形成后，脱离，并评估其在声激励的作用。结果发现，对于缓慢增长的气泡的射流确实使颈部塌陷期间的总体积减少的显着差异，但它不是在整体声激励的主导作用。
It has recently been demonstrated that air bubbles released from a nozzle are excited into volume mode oscillations by the collapse of the neck of air formed at the moment of bubble detachment. A pulse of sound is caused by these breathing mode oscillations, and the sound of air-entraining flows is made up of many such pulses emitted as bubbles are created. This paper is an elaboration on a JASA-EL paper, which examined the acoustical excitation of bubbles released from a nozzle. Here, further details of the collapse of a neck of air formed at the moment of bubble formation and its implications for the emission of sound by newly formed bubbles are presented. The role of fluid surface tension was studied using high-speed photography and found to be consistent with a simple model for neck collapse. A re-entrant fluid jet forms inside the bubble just after detachment, and its role in acoustic excitation is assessed. It is found that for slowly-grown bubbles the jet does make a noticeable difference to the total volume decrease during neck collapse, but that it is not a dominant effect in the overall acoustic excitation.