Role of Correlations in the Collective Behavior of Microswimmer Suspensions.
Role of Correlations in the Collective Behavior of Microswimmer Suspensions.
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相关性在微型游泳者悬浮液集体行为中的作用。
DOI：
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发表时间：
2017
影响因子：
8.6
通讯作者：
A. Morozov
中科院分区：
文献类型：
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作者：
Joakim Stenhammar;C. Nardini;R. Nash;D. Marenduzzo;A. Morozov
在这封信中，我们研究了大量的自我推进的微型游泳者浸没在流体中的集体行为。使用前所未有的大规模格子玻尔兹曼模拟，我们再现了细菌湍流的过渡。我们发现，即使低于过渡，游泳运动在一个相关的方式，不能描述的平均场方法。我们开发了一种新的动力学理论，捕捉这些相关性，是非微扰的游泳者密度。为了提供一个实验上可访问的相关措施，我们计算被动示踪剂的扩散，并揭示其非平凡的密度依赖性。该理论是在定量协议与格子玻尔兹曼模拟，并捕捉不对称的推和拉游泳下面的过渡到湍流。
In this Letter, we study the collective behavior of a large number of self-propelled microswimmers immersed in a fluid. Using unprecedentedly large-scale lattice Boltzmann simulations, we reproduce the transition to bacterial turbulence. We show that, even well below the transition, swimmers move in a correlated fashion that cannot be described by a mean-field approach. We develop a novel kinetic theory that captures these correlations and is nonperturbative in the swimmer density. To provide an experimentally accessible measure of correlations, we calculate the diffusivity of passive tracers and reveal its nontrivial density dependence. The theory is in quantitative agreement with the lattice Boltzmann simulations and captures the asymmetry between pusher and puller swimmers below the transition to turbulence.