Absolute and convective instabilities of a film flow down a vertical fiber subjected to a radial electric field.
Absolute and convective instabilities of a film flow down a vertical fiber subjected to a radial electric field.
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DOI：
10.1103/physreve.97.013109
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发表时间：
2018-01
期刊：
影响因子：
--
通讯作者：
Rong Liu;Xue Chen;Zijing Ding
中科院分区：
文献类型：
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作者：
Rong Liu;Xue Chen;Zijing Ding
我们考虑了在径向电场作用下沿垂直纤维的重力驱动流的运动。这种流动表现出丰富的动力学，包括液滴或珠粒的形成，由瑞利-高原机制驱动，该机制由重力的存在以及界面处的麦克斯韦应力修改。通过时空稳定性分析，研究了电场对绝对对流不稳定（AI-CI）特性的影响。我们对薄膜的非线性演化进行了数值模拟，以研究从CI到AI制度的转变。数值结果与时空稳定性分析吻合得很好。非线性模拟的爆破行为预示了由于电场的影响，界面触地奇点的形成。我们试图将爆炸行为与AI-CI特征联系起来。结果表明，奇异性主要发生在AI区域。结果表明，由于电场增强了薄膜的绝对不稳定性，薄膜可能有形成非常尖锐尖端的趋势。我们进行了理论分析，研究的奇异性的行为。结果表明，奇点的时空距离存在自相似性。
We consider the motion of a gravity-driven flow down a vertical fiber subjected to a radial electric field. This flow exhibits rich dynamics including the formation of droplets, or beads, driven by a Rayleigh-Plateau mechanism modified by the presence of gravity as well as the Maxwell stress at the interface. A spatiotemporal stability analysis is performed to investigate the effect of electric field on the absolute-convective instability (AI-CI) characteristics. We performed a numerical simulation on the nonlinear evolution of the film to examine the transition from CI to AI regime. The numerical results are in excellent agreement with the spatiotemporal stability analysis. The blowup behavior of nonlinear simulation predicts the formation of touchdown singularity of the interface due to the effect of electric field. We try to connect the blowup behavior with the AI-CI characteristics. It is found that the singularities mainly occur in the AI regime. The results indicate that the film may have a tendency to form very sharp tips due to the enhancement of the absolute instability induced by the electric field. We perform a theoretical analysis to study the behaviors of the singularities. The results show that there exists a self-similarity between the temporal and spatial distances from the singularities.