Emergent rheotaxis of shape-changing swimmers in Poiseuille flow
Emergent rheotaxis of shape-changing swimmers in Poiseuille flow
复制标题
泊肃叶流中变形游泳者的突现趋变性
DOI：
10.1017/jfm.2022.474
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发表时间：
2022
影响因子：
3.7
通讯作者：
Dalwadi M.P.
中科院分区：
文献类型：
--
作者：
Walker B.J.;Ishimoto K.;Moreau C.;Gaffney E.A.;Dalwadi M.P.
Omori 等人最近提出了一个简单的泊肃叶流中变形游泳者运动的模型，并进行了数值探索。 （《流体力学杂志》，第 930 卷，2022 年，A30）。这些探索表明，少数相互作用的力学可以驱动该模型中的长期行为，这些行为是在充分研究的藻类衣藻及其在这种流动中的流变行为的背景下进行的。在这里，我们通过多尺度渐近分析来分析该模型，寻求正式确定影响泊肃叶流中这些游泳者行为的因果因素。通过捕获类似哈密顿量的演化，我们揭示了单个游泳者相关常数的长期漂移的起源，该常数的符号决定了游泳者的最终行为。该常数捕获了变形游泳者的振荡速度和有效流体动力学形状之间的非线性相互作用，驱动朝向或远离趋变性的漂移。
A simple model for the motion of shape-changing swimmers in Poiseuille flow was recently proposed and numerically explored by Omori et al. (J. Fluid Mech., vol. 930, 2022, A30). These explorations hinted that a small number of interacting mechanics can drive long-time behaviours in this model, cast in the context of the well-studied alga Chlamydomonas and its rheotactic behaviours in such flows. Here, we explore this model analytically via a multiple-scale asymptotic analysis, seeking to formally identify the causal factors that shape the behaviour of these swimmers in Poiseuille flow. By capturing the evolution of a Hamiltonian-like quantity, we reveal the origins of the long-term drift in a single swimmer-dependent constant, whose sign determines the eventual behaviour of the swimmer. This constant captures the nonlinear interaction between the oscillatory speed and effective hydrodynamic shape of deforming swimmers, driving drift either towards or away from rheotaxis.