论文标题
小蠕虫在小雷诺数上以时间依赖的速度移动的小蠕动器上的流体动力
Hydrodynamic force on a small squirmer moving with a time-dependent velocity at small Reynolds numbers
论文作者
论文摘要
我们在扰动理论中考虑了对流和不稳定的液体惯性效应，在静止状态下以时间依赖性速度移动的小球形，不稳定的蠕动器上的流体动力。我们的结果将Lovalenti和Brady（1993）的结果从被动到活跃的球形粒子概括。我们发现对流惯性将历史归因变为流体动力，就像被动颗粒一样。我们确定流体动力如何取决于不稳定的蠕动者的游泳步态。由于游泳打破了问题的球形对称性，因此力不完全由渐近匹配问题的外溶液确定，因为它是用于被动球的。由于内部问题的不均匀解决方案，还有其他贡献。我们还计算了干扰流量，说明了当粒子突然开始时突然停止时，对流和不稳定的效果。
We calculate the hydrodynamic force on a small spherical, unsteady squirmer moving with a time-dependent velocity in a fluid at rest, taking into account convective and unsteady fluid inertia effects in perturbation theory. Our results generalise those of Lovalenti and Brady (1993) from passive to active spherical particles. We find that convective inertia changes the history-contribution to the hydrodynamic force, as it does for passive particles. We determine how the hydrodynamic force depends on the swimming gait of the unsteady squirmer. Since swimming breaks the spherical symmetry of the problem, the force is not completely determined by the outer solution of the asymptotic matching problem, as it is for passive spheres. There are additional contributions due to the inhomogeneous solution of the inner problem. We also compute the disturbance flow, illustrating convective and unsteady effects when the particle experiences a sudden start followed by a sudden stop.
