Interplay between particulate fouling and its flow disturbance: Numerical and experimental studies

In this study, we examine the complex interplay between particulate fouling and flow disturbance via particle simulation and microfluidic experiments. From the experiment, it is found that a particle is transported and deposited following the streamline, which is affected by the existing particle deposit. Inspired by this microfluidic observation, we develop a novel coarse-grained particle simulation, which continuously updates the flow field by considering the particle deposits, to investigate particulate fouling more intensively. Four physical factors are proposed to describe quantitatively the particulate fouling: effective collision, hydrodynamic boundary layer, inaccessible zone, and high shear stress region. In the initial stage of fouling, a number of particles are deposited within the growing hydrodynamic boundary layer, where effective collisions are readily achieved. In the latter stage of fouling, the inaccessible zone and high shear stress region are expanded, which causes the particle deposition rate to decrease. This result provides a comprehensive understanding of the particulate fouling through the combination of the four physical factors.