KU Leuven, Department of Chemical Engineering, Celestijnenlaan 200F, 3001 Leuven, Belgium.
KU Leuven, Department of Chemical Engineering, Celestijnenlaan 200F, 3001 Leuven, Belgium.
Ultrason Sonochem. 2023 Feb;93:106300. doi: 10.1016/j.ultsonch.2023.106300. Epub 2023 Jan 18.
In this work, we characterize acoustic resonance phenomena occurring between gas bubbles in a segmented gas-liquid flow in a microchannel irradiated with a frequency around 500 kHz. A large acoustic amplitude can be reached, leading to gas-liquid interface deformation, atomization of micrometer sized droplets, and cavitation. A numerical approach combining an acoustic frequency-domain solver and a Lagrangian Surface-Evolver solver is introduced to predict the acoustic deformation of gas-liquid interfaces and the dynamic acoustic magnitude. The numerical approach and its assumptions were validated with experiments, for which a good agreement was observed. Therefore, this numerical approach allows to provide a description and an understanding of the acoustic nature of these phenomena. The acoustic pressure magnitude can reach hundreds of kPa to tens of MPa, and these values are consistent with the observation of atomization and cavitation in the experiments. Furthermore, volume of fluid simulations were performed to predict the atomization threshold, which was then related to acoustic resonance. It is found that dynamic acoustic resonance gives rise to atomization bursts at the gas bubble surface. The presented approach can be applied to more complex acoustic fields involving more complex channel geometries, vibration patterns, or two-phase flow patterns.
在这项工作中，我们研究了在微通道中分段气液流动中，气泡之间在 500kHz 左右频率下发生的声共振现象。可以达到较大的声幅，导致气液界面变形、微米大小的液滴雾化和空化。引入了一种结合声学频域求解器和拉格朗日曲面演化求解器的数值方法，以预测气液界面的声学变形和动态声学幅度。数值方法及其假设通过实验进行了验证，观察到了良好的一致性。因此，这种数值方法可以提供对这些现象的声学性质的描述和理解。声压幅度可达数百 kPa 到数十 MPa，这些值与实验中观察到的雾化和空化一致。此外，还进行了流体体积法模拟以预测雾化阈值，然后将其与声共振相关联。结果发现，动态声共振会在气泡表面引发雾化爆发。所提出的方法可应用于涉及更复杂通道几何形状、振动模式或两相流模式的更复杂声场。
