BEHAVIOR OF A SINGLE BUBBLE IN A NONUNIFORM D.C. ELECTRIC FIELD
BEHAVIOR OF A SINGLE BUBBLE IN A NONUNIFORM D.C. ELECTRIC FIELD
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DOI：
10.1080/00986445.2010.493103
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发表时间：
2010-10
影响因子：
2.5
通讯作者：
M. Jalaal;B. Khorshidi;E. Esmaeilzadeh;F. Mohammadi
中科院分区：
文献类型：
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作者：
M. Jalaal;B. Khorshidi;E. Esmaeilzadeh;F. Mohammadi
实验和数值模拟研究了非均匀电场对介电液体中单个惰性气泡的形成、脱离和破碎的影响。在实验中，气泡以恒定的流速通过测试池底壁处的孔注入煤油中。将液体置于水平和垂直电极之间的非均匀电场中。在实验过程中，气泡的行为被连续记录，并且借助图形软件从连续帧中数字化地提取气泡的位置、形状和体积偏离。实验结果表明，在非均匀电场作用下，气泡呈扁长形，并向与接地电极相反的方向倾斜。随着电势的增加，气泡的生长时间和脱离体积将不断减小。在足够高的电压下也观察到气泡破裂。作为进一步的研究，进行了3-D数值模拟，使用商业有限元代码（Comsol Multiphysics），以确定电应力沿着气泡表面的分布。数值结果表明，非均匀电场在气泡表面产生了不均匀应力。气泡在水平分量的作用下被压缩和偏转，在垂直分量的作用下被拉长。数值结果证实了实验中观察到的气泡的物理行为。
The effects of a nonuniform electric field on the formation, detachment, and breakup of a single inert bubble surrounded by a dielectric liquid were studied experimentally and numerically. In experiments, air bubbles were injected into kerosene at a constant flow rate through an orifice at the bottom wall of the test cell. The liquid was subjected to a nonuniform electric field, applied between the horizontal and vertical electrodes. During the experiments, the behavior of bubbles was recorded continuously, and the position, shape, and volume departure of the bubbles were digitally extracted from the sequential frames with the aid of graphical software. The experimental results show that in the presence of the nonuniform electric field, bubbles take a prolate shape and skew to the opposite direction of the ground electrode. With an increase in the electric potential, the bubble growth time and departure volume will decrease continuously. Bubble breakup is also observed at high enough voltages. As a further study, a 3-D numerical simulation was performed, using a commercial finite element code (Comsol Multiphysics) to determine the distribution of electric stresses along the bubble surface. The numerical results show that the nonuniform electric field generates some inhomogeneous stresses at the bubble surface. The bubble is compressed and deviated by the horizontal component and elongated by the vertical component. Numerical outcomes prove the physical behavior of the bubble observed in the experiments.