Describing Hydrodynamic Particle Removal from Surfaces Using the Particle Reynolds Number

The fundamental processes related to the removal of fine particles from surfaces in a hydrodynamic flow field are not adequately understood. A critical particle Reynolds number approach is proposed to assess these mechanisms for fine particles when surface roughness is small compared to particle diameter. At and above the critical particle Reynolds number, particle removal occurs, while below the critical value, particles remain attached to a surface. The system under consideration consists of glass particles adhering to a glass surface in laminar channel flow. Our results indicate rolling is the removal mechanism, which is in agreement with the literature. Theoretical results of the critical particle Reynolds number model for rolling removal are in general agreement with experimental data when particle size distribution, particle and surface roughness, and system Hamaker constant are taken into account.