Bumpy Particle Adhesion and Removal in Turbulent Flows Including Electrostatic and Capillary Forces

Abstract

The effect of electrostatic and capillary forces on bumpy particle adhesion and removal in turbulent flows is studied. We use the JKR theory and account for the increase of adhesion by capillary force. The effects of electrostatic forces and nonlinear hydrodynamic drag are included in the analyses. The criteria for incipient rolling and sliding detachments and electrostatic lifting removal are evaluated. A turbulence burst model is used for evaluating the peak air velocity near the substrate. The critical shear velocities for detaching particles of different sizes under different conditions are evaluated. The electric field strength needed for electrostatic removal of particles with different charges is also estimated. The results are compared with those obtained in the absence of the capillary force. Comparisons of the model predictions with the available experimental data are also presented.

Keywords:

• Adhesion and removal
• Bumpy particle
• Capillary force
• Electrostatics

ACKNOWLEDGMENT

The financial support of the Environmental Protection Agency (EPA) and the NYSTAR Center of Excellence is gratefully acknowledged.