Liquid jet directionality and droplet behavior during emulsification of two liquids due to acoustic cavitation
Liquid jet directionality and droplet behavior during emulsification of two liquids due to acoustic cavitation
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DOI：
10.1016/j.ultsonch.2019.104874
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发表时间：
2020-04-01
影响因子：
8.4
通讯作者：
Komarov, Sergey, V
中科院分区：
文献类型：
--
作者：
Yamamoto, Takuya;Komarov, Sergey, V
本研究数值研究了水/镓/空气和水/硅油/空气系统中乳化过程中声空化的液体射流特性。研究发现，当一种液体在另一种液体中的微小液滴附近发生声空化时，会产生高速液体射流。液体射流的速度很大程度上取决于超声波压力，随着压力幅度的增加单调增加。此外，空化气泡和液滴之间的初始距离显着影响射流速度。结果表明，当液滴与空化泡之间的初始距离适中时，速度取最大值。令人惊讶的是，发现液体喷射方向取决于液滴特性。具体而言，在水/镓/空气系统的情况下，液体射流的方向是朝向液滴，反之亦然，在水/硅油/空气系统的情况下，射流从液滴引导。射流方向性可以通过气泡收缩过程中产生的高压点的位置来解释。
The present study numerically investigates liquid-jet characteristics of acoustic cavitation during emulsification in water/gallium/air and water/silicone oil/air systems. It is found that a high-speed liquid jet is generated when acoustic cavitation occurs near a minute droplet of one liquid in another. The velocity of liquid jet significantly depends on the ultrasonic pressure monotonically increasing as the pressure amplitude increases. Also, the initial distance between cavitation bubble and liquid droplet affects the jet velocity significantly. The results revealed that the velocity takes maximum values when the initial distance between the droplet and cavitation bubble is moderate. Surprisingly, the liquid jet direction was found to depend on the droplet properties. Specifically, the direction of liquid jet is toward the droplet in the case of water/gallium/air system, and vice versa the jet is directed from the droplet in the case of water/silicone oil/air system. The jet directionality can be explained by location of the high-pressure spot generated during the bubble contraction.