论文标题
在层流和动荡的kolmogorov流中的细长游泳者对齐
Alignment of elongated swimmers in a laminar and turbulent Kolmogorov flow
论文作者
论文摘要
许多水生微生物都可以游泳。在自然环境中，他们通常在流量存在下这样做。近年来，已经表明，游泳和流的相互作用会引起有趣且与生物学相关的现象，例如在特定流动区域中微生物的积累以及与流量特性的局部对齐。在这里，我们考虑了在稳定和湍流条件下的Kolmogorov流动流的伸长微晶状体的机械模型。通过在简化的随机环境中分析计算支持的直接数值模拟，我们发现游泳方向与局部速度的比对是一种普遍现象。我们还探讨了通常在稳定流中观察到的微生物的积累如何通过不稳定波动的存在来改变。
Many aquatic microorganisms are able to swim. In natural environments they typically do so in the presence of flows. In recent years it has been shown that the interplay of swimming and flows can give rise to interesting and biologically relevant phenomena, such as accumulation of microorganisms in specific flow regions and local alignment with the flow properties. Here, we consider a mechanical model for elongated microswimmers in a Kolmogorov flow, a prototypic shear flow, both in steady and in turbulent conditions. By means of direct numerical simulations, supported by analytical calculation in a simplified stochastic setting, we find that the alignment of the swimming direction with the local velocity is a general phenomenon. We also explore how the accumulation of microorganisms, typically observed in steady flows, is modified by the presence of unsteady fluctuations.
