ON PARTICLE ADHESION AND REMOVAL MECHANISMS IN TURBULENT FLOWS

Particle removal mechanisms in a turbulent flow am examined and two models which are based on the structure of turbulence near wall flow are described. The theory of critical moment, along with the sliding detachment models, is used, and the effects of the near-wall coherent vortices, as well as turbulence burst/inrush phenomena, are included. The down sweep flow patterns are modeled as viscous stagnation point flows. The hydrodynamic force and torque acting on a spherical particle attached to a wall are used in the model developments. For different adhesion models, the minimum critical shear velocities for removing particles of different sizes am evaluated. The model predictions are compared with the available data and discussed.