论文标题
粒子运动附近的粗糙表面
Particle motion nearby rough surfaces
论文作者
论文摘要
我们研究颗粒与固体，粗糙边界之间的流体动力耦合，其特征在于随机表面纹理。使用Lorentz倒数定理，我们得出球形粒子的大迁移率张量的分析表达式，发现粗糙度诱导的速度与表面的特征波长无单声道变化。与平面壁附近的沉积相反，我们的理论预测了连续的粒子翻译横向和垂直于施加力。最突出的是，这种运动以粒子位移的差异表现出来，这些粒子位移在沿力方向上二次生长。通过表面粗糙度产生粒子沉积的表面粗糙度更靠近或离表面，这是合理的，这需要沉降速度的显着差异。
We study the hydrodynamic coupling between particles and solid, rough boundaries characterized by random surface textures. Using the Lorentz reciprocal theorem, we derive analytical expressions for the grand mobility tensor of a spherical particle and find that roughness-induced velocities vary nonmonotonically with the characteristic wavelength of the surface. In contrast to sedimentation near a planar wall, our theory predicts continuous particle translation transverse and perpendicular to the applied force. Most prominently, this motion manifests itself in a variance of particle displacements that grows quadratically in time along the direction of the force. This increase is rationalized by surface roughness generating particle sedimentation closer to or farther from the surface, which entails a significant variability of settling velocities.
