A minimal model for a hydrodynamic fingering instability in microroller suspensions
A minimal model for a hydrodynamic fingering instability in microroller suspensions
复制标题
微滚子悬架中流体动力指法不稳定性的最小模型
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
P. Chaikin
中科院分区：
文献类型：
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作者：
Blaise Delmotte;M. Driscoll;A. Donev;P. Chaikin
我们推导出一个最小连续模型，以研究最近在地板附近的微辊悬浮液中发现的指进不稳定性背后的流体动力学机制[Drivel et al. Nature Physics，2016]。我们的模型，由两条连续的线的rotlets，表现出线性不稳定性驱动的流体动力学相互作用，并再现在大尺度粒子模拟和实验中观察到的lengthscale选择。通过调整只有一个参数，两条线之间的距离，我们的色散关系表现出定量的模拟和定性的实验测量协议。我们的线性稳定性分析表明，这种不稳定性是由附近的无滑动表面的微辊产生的平流和横向流的组合。我们简单的模型提供了一个有趣的形式主义，以表征其他流体动力学不稳定性，尚未得到很好的理解，如尺寸尺度的选择，在悬浮液中的颗粒附近的壁沉积，或最近观察到的形成的旅行声子在系统中的限制驱动粒子。
We derive a minimal continuum model to investigate the hydrodynamic mechanism behind the fingering instability recently discovered in a suspension of microrollers near a floor [Driscoll et al. Nature Physics, 2016]. Our model, consisting of two continuous lines of rotlets, exhibits a linear instability driven only by hydrodynamics interactions, and reproduces the lengthscale selection observed in large scale particle simulations and in experiments. By adjusting only one parameter, the distance between the two lines, our dispersion relation exhibits quantitative agreement with the simulations and qualitative agreement with experimental measurements. Our linear stability analysis indicate that this instability is caused by the combination of the advective and transverse flows generated by the microrollers near a no-slip surface. Our simple model offers an interesting formalism to characterize other hydrodynamic instabilities that have not been yet well understood, such as size scale selection in suspensions of particles sedimenting adjacent to a wall, or the recently observed formations of traveling phonons in systems of confined driven particles.
影响因子：
44.1
作者：
Marchetti, M. C.;Joanny, J. F.;Simha, R. Aditi
通讯作者：
Simha, R. Aditi