Characterization of adhesion force in aerodynamic particle resuspension (vol 28, pg 89, 2019)

Microparticle adhesion and resuspension are critical in studies of surface contamination, non-contact sampling, environmental and occupational health assessments, and surface cleaning. Direct adhesion measurement methods that evaluate the pull-out force are often limited to a range of operational conditions. The established analytical models need additional terms to account for roughness, morphology, and environmental conditions. The proposed aerodynamic method offers a non-contact evaluation of particle-surface adhesion force. In this work, aerodynamic detachment of silica microspheres in the 12–26 µm range from a smooth glass surface is studied experimentally. Computational fluid dynamics (CFD) calculates the drag and lift forces acting on the particles. The adhesion force is derived from the moment balance required to initiate the rolling motion of the particle. The aerodynamic forces acting on the particle, calculated by the CFD, agree with the theoretical values for a spherical particle in the shear flow in the Stokes regime (Re<1). The aerodynamic force calculations are extended to Re = 1–1000. The aerodynamic method shows a monotonically increasing dependency of the adhesion force with particle diameter; the results are consistent with the theoretical models and the published experimental data. The approach can be extended to more complex systems, including the effects of roughness, particle morphology and aging, and a range of environmental conditions.