论文标题
腹细菌的壁夹：一项中尺度流体动力学研究
Wall entrapment of peritrichous bacteria: A mesoscale hydrodynamics simulation study
论文作者
论文摘要
大肠杆菌细菌等微晶状体会积累并在墙壁附近表现出有趣的动力学，受水动力和空间相互作用的控制。深入了解潜在机制和主要相互作用，需要对夹带过程进行详细的表征。我们采用中尺度的流体动力学模拟方法来研究无滑壁的大肠杆菌细胞的夹层。该细胞由带有几个显式螺旋鞭毛的球形体体建模。可以区分陷阱过程的三个阶段：接近的机制，其中一个细胞在几乎直轨道上向墙游动；散射状态，细胞触摸墙壁，并以重新定位；和表面降低的制度。我们的模拟表明，空间相互作用可能主导着捕集过程，但是，流体动力相互作用减慢了靠近边界的吸附动力学，并暗示壁上的圆形运动。细胞的运动的特征是强烈的摇摆动力学，细胞优先指向壁。
Microswimmers such as E. Coli bacteria accumulate and exhibit an intriguing dynamics near walls, governed by hydrodynamic and steric interactions. Insight into the underlying mechanisms and predominant interactions demand a detailed characterization of the entrapment process. We employ a mesoscale hydrodynamics simulation approach to study entrapment of a E. coli-type cell at a no-slip wall. The cell is modeled by a spherocylindrical body with several explicit helical flagella. Three stages of the entrapment process can be distinguished: the approaching regime, where a cell swims toward the wall on a nearly straight trajectory; a scattering regime, where the cell touches the wall, with an reorientation; and a surface-swimming regime. Our simulations show that steric interactions may dominate the entrapment process, yet, hydrodynamic interactions slow down the adsorption dynamics close to the boundary and imply a circular motion on the wall. The locomotion of the cell is characterized by a strong wobbling dynamics, with cells preferentially pointing toward the wall.
