PARTICLE DETACHMENT FROM ROUGH SURFACES IN TURBULENT FLOWS

Two how structure-based models for particle resuspension from rough su rfaces in turbulent streams are developed. It is assumed that the real area of contact is determined by elastic deformation of asperities an d the effect of topographic properties of surfaces are included. The J KR adhesion model is used to analyze the behaviour of individual asper ities. The theories of rolling and sliding detachment are used and the flow-induced resuspension is studied. The effects of the near-wall co herent eddies, and turbulence urst/inrush motion are included in the m odel development. The critical shear velocities needed to detach diffe rent sized particles from rough surfaces under various conditions are evaluated and discussed. The model predictions are compared with the a vailable experimental data and good agreement is obtained.