The behavior of microparticle assemblage moving through the saturated pores in a fibrous layer has been investigated numerically. We adopted a particle model to express the straight and tortuous fibrous layers and calculated the velocities of individual microparticles using the Stokesian dynamics approach assuming the Stokes flow. The simulation results showed that the particles spread as they moved through the layer. This is interpreted as hydrodynamic diffusion caused by the hydrodynamic interaction dominant in the Stokes flow. More pronounced diffusion was observed in the tortuous fibrous layer than in the straight one. It was found that the velocity of each particle deviated more from the ensemble average velocity of the assemblage in the tortuous fibrous layer. It was also observed that the tortuous fibrous layers exhibited greater variation in the size of the pores where particles passed. Our results quantitatively indicated that the tortuous fibrous layer consisted of a wide variety of pore sizes, which affects the velocity of the particles passing through it. Consequently, the difference in each particle velocity causes the hydrodynamic diffusion. It was also revealed that the subtle difference in the fiber shape substantially influences the hydrodynamic behavior of the particles moving inside.

已经对微粒组合在纤维层中的饱和孔隙中移动的行为进行了数值研究。我们采用粒子模型来表达笔直和曲折的纤维层，并使用斯托克斯动力学方法计算单个微粒的速度，假设斯托克斯流。模拟结果表明，粒子在穿过层时会扩散。这被解释为由斯托克斯流中占主导地位的流体动力学相互作用引起的流体动力学扩散。在曲折的纤维层中观察到比在直的纤维层中更明显的扩散。发现每个粒子的速度与曲折纤维层中集合的集合平均速度的偏差更大。还观察到，曲折的纤维层在颗粒通过的孔的尺寸上表现出更大的变化。我们的结果定量地表明，曲折的纤维层由多种孔径组成，这会影响颗粒通过它的速度。因此，每个粒子速度的差异导致流体动力学扩散。研究还表明，纤维形状的细微差别会显着影响内部移动的颗粒的流体动力学行为。