Joshi Chaitanya, Zarei Zahra, Norton Michael M, Fraden Seth, Baskaran Aparna, Hagan Michael F
Department of Physics and Astronomy, Tufts University, 574 Boston Avenue, Medford, Massachusetts 02155, USA.
Martin Fisher School of Physics, Brandeis University, 415 South Street, Waltham, Massachusetts 02453, USA.
Soft Matter. 2023 Jul 26;19(29):5630-5640. doi: 10.1039/d3sm00477e.
Confinement can be used to systematically tame turbulent dynamics occurring in active fluids. Although periodic channels are the simplest geometries to study confinement numerically, the corresponding experimental realizations require closed racetracks. Here, we computationally study 2D active nematics confined to such a geometry-an annulus. By systematically varying the annulus inner radius and channel width, we bridge the behaviors observed in the previously studied asymptotic limits of the annulus geometry: a disk and an infinite channel. We identify new steady-state behaviors, which reveal the influence of boundary curvature and its interplay with confinement. We also show that, below a threshold inner radius, the dynamics are insensitive to the presence of the inner hole. We explain this insensitivity through a simple scaling analysis. Our work sheds further light on design principles for using confinement to control the dynamics of active nematics.
限制作用可用于系统地驯服活性流体中出现的湍流动力学。尽管周期性通道是在数值上研究限制作用最简单的几何形状，但相应的实验实现需要封闭的跑道。在此，我们通过计算研究二维活性向列相限制在这样一种几何形状——环形区域中的情况。通过系统地改变环形区域的内半径和通道宽度，我们弥合了在先前研究的环形区域几何形状的渐近极限中观察到的行为：圆盘和无限通道。我们识别出了新的稳态行为，这些行为揭示了边界曲率的影响及其与限制作用的相互作用。我们还表明，在内半径低于阈值时，动力学对内孔的存在不敏感。我们通过简单的标度分析解释了这种不敏感性。我们的工作进一步阐明了利用限制作用来控制活性向列相动力学的设计原则。
