论文标题
流体流体界面上微武器的重新定位动力学
Reorientation dynamics of microswimmers at fluid-fluid interfaces
论文作者
论文摘要
我们根据其流场的力偶极子和源偶极组成分研究了被困在流体界面上的球形微晶状体的定向和翻译动力学。使用数值模拟和分析计算，我们表明，力偶极子施加了平行于界面的扭矩，定向推动器，并朝着正常方向施加。源偶极子仅导致粒子旋转与以前的研究一致两种流体之间的有限粘度对比。这两种贡献的叠加导致旋转动力学，其稳态方向取决于力和源偶极子的相对大小。在一般情况下，观察到具有较弱的力偶极子和强力拉杆的游泳者会垂直于界面并固定，而强的推动器则具有有限的倾斜角度，倾向于较低的粘度流体，并沿界面游泳。
We study the orientational and translational dynamics of spherical microswimmers trapped at fluid interfaces, in terms of the force dipole and source dipole components of their flow field. Using numerical simulations and analytical calculations, we show that the force dipole exerts a torque, orienting pushers parallel to the interface, and pullers in normal direction. The source dipole results in particle rotation only for a finite viscosity contrast between the two fluids, in agreement with previous studies. The superposition of these two contributions leads to an rotational dynamics with a steady-state orientation that depends on the relative magnitudes of the force and source dipoles. In the general case, swimmers with weak force dipoles and strong pullers are observed to align perpendicular to the interface and become stationary, while strong pushers have a finite inclination angle towards the lower viscosity fluid and swim along the interface.
