RESUSPENSION OF PARTICULATES FROM SURFACES TO TURBULENT FLOWS - REVIEW AND ANALYSIS

The paper reviews the state of the art of aerosol resuspension researc h. Five different theoretical models of particle reentrainment are des cribed. Accordingly, the expressions for resuspension from a surface e xposed to fluid flow are explained. The advantages and shortcomings of the models are compared. Experimental results from the literature are summarized and presented in the form of tables. Dimensional analysis is applied to the experimental results, introducing the wall shear vel ocity as a universal parameter which determines the flow character. Th e advantages and limitations of the existing models of aerosol resuspe nsion are assessed by means of a comparison between theory and experim ents, recast in terms of dimensionless groups. Critical analysis shows that, in general, presently available experimental data do not suppor t the existing theoretical models. Models of adhesion of small particl es to solid surfaces are also reviewed. The role of van der Waals and electrical interactions in formation of contact with a surface is anal yzed, together with the influence of elastic and plastic deformations. The effects of surface roughness, particle type and system history ar e discussed. The work analyzes the application of boundary-layer turbu lence, especially the presence of quasi-periodic repeating patterns of coherent motion, to resuspension. Various mechanisms for generating t he hydrodynamic force in turbulent and shear flows at different Reynol ds numbers are discussed. Dimensionless expressions for hydrodynamic a nd surface forces and moments are developed allowing comparison and ev aluation of their relative importance. Possible mechanisms of resuspen sion are proposed.