Particle Detachment from Rough Surfaces in Turbulent Flows

Abstract

Two flow structure-based models for particle resuspension from rough surfaces in turbulent streams are developed. It is assumed that the real area of contact is determined by elastic deformation of asperities and the effect of topographic properties of surfaces are included. The JKR adhesion model is used to analyze the behaviour of individual asperities. The theories of rolling and sliding detachment are used and the flow-induced resuspension is studied. The effects of the near-wall coherent eddies, and turbulence urst/inrush motion are included in the model development. The critical shear velocities needed to detach different sized particles from rough surfaces under various conditions are evaluated and discussed. The model predictions are compared with the available experimental data and good agreement is obtained.

Key Words:

• adhesion
• detachment
• roughness
• turbulent flow
• resuspension