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arXiv · 2111.03102

Electrically-controlled self-similar evolution of viscous fingering patterns in radial Hele-Shaw flows

Pedro H. A. Anjos·Meng Zhao·John Lowengrub·Shuwang Li
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Abstract

Time-dependent injection strategies are commonly employed to control the number of viscous fingers emerging at the interface separating two fluids during radial displacement in Hele-Shaw flows. Here we demonstrate theoretically that such a usual controlling method is significantly improved by taking advantage of an electro-osmotic flow generated by applying an external electric field. More specifically, under the coupled action of time-varying electric currents and injection rates, we design a strategy capable of controlling not only the number of fingers emerging at the interface but also when (and if) the self-similar evolution occurs. In addition, the level of instability of the $n$-fold fingered patterns can also be tuned. This improved control over the interfacial features cannot be realized by the sole consideration of a time-varying injection rate. Perturbative second-order mode-coupling analysis and boundary integral simulations confirm that the validity and effectiveness of the controlling protocol go beyond the linear regime.

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Pedro H. A. Anjos, Meng Zhao, John Lowengrub, Shuwang Li. 2021-11-04. Electrically-controlled self-similar evolution of viscous fingering patterns in radial Hele-Shaw flows. https://arxiv.org/abs/2111.03102

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