Effects of Electrostatic and Capillary Forces and Surface Deformation on Particle Detachment in Turbulent Flows

摘要

In this work the rolling detachment of particles from surfaces in the presence of electrostatic and capillary forces based on the maximum adhesion resistance was studied. The effective thermodynamic work of adhesion, including the effects of electrostatic and capillary forces, was used in the analysis. The Johnson, Kendall and Roberts (JKR) and Derjaguin, Muller and Toporov (DMT) models for elastic interface deformations and the Maugis-Pollock model for plastic deformation were extended to include the effect of electrostatic and capillary forces. Under turbulent flow conditions, the criteria for incipient rolling detachment were evaluated. The turbulence burst model was used to evaluate the airflow velocity near the substrate. The critical shear velocities for removal of particles of different sizes were evaluated, and the results were compared with those without electrostatic and capillary forces. The model predictions were compared with the available experimental data and good agreement was observed.