论文标题
细菌和被动物体的主动悬浮液：近场对动力学的模型
Active suspensions of bacteria and passive objects: a model for the near field pair dynamics
论文作者
论文摘要
近场流体动力相互作用对于确定在主动悬浮液中观察到的许多重要的紧急行为至关重要，但迄今尚未成功建模。在这项工作中，我们提出了一个有效的模型，能够有效捕获近场流体动力相互作用的本质，该模型通过由大肠杆菌和球形示踪剂组成的教学模型系统进行数值验证。提出的模型仅通过一种抗电阻系数有效地捕获了近场流体动力学的所有细节，该系数与保守性质的有效相互作用从根本上不同，因此无法取代。在研究细菌追踪对动力学的散射角的关键测试案例中，基于提议的模型的计算揭示了参数空间中的一个区域，其中细菌被球形示踪剂捕获，这种现象在实验中定期观察到，但任何现有模型都无法解释。
Near field hydrodynamic interactions are essential to determine many important emergent behaviors observed in active suspensions, but have not been successfully modeled so far. In this work we propose an effective model capable of efficiently capturing the essence of the near field hydrodynamic interactions, validated numerically by a pedagogic model system consisting of an E. coli and a spherical tracer. The proposed model effectively captures all the details of near field hydrodynamics through only a tensorial coefficient of resistance, which is fundamentally different from, and thus cannot be replaced by, an effective interaction of conservative nature. In a critical test case that studies the scattering angle of the bacterium-tracer pair dynamics, calculations based on the proposed model reveals a region in parameter space where the bacterium is trapped by the spherical tracer, a phenomenon that is regularly observed in experiments but cannot be explained by any existing model.
