Resuspension of particulates from surfaces to turbulent flows—Review and analysis

The paper reviews the state of the art of aerosol resuspension research. Five different theoretical models of particle reentrainment are described. Accordingly, the expressions for resuspension from a surface exposed 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 velocity as a universal parameter which determines the flow character. The advantages and limitations of the existing models of aerosol resuspension are assessed by means of a comparison between theory and experiments, recast in terms of dimensionless groups. Critical analysis shows that, in general, presently available experimental data do not support the existing theoretical models. Models of adhesion of small particles to solid surfaces are also reviewed. The role of van der Waals and electrical interactions in formation of contact with a surface is analyzed, together with the influence of elastic and plastic deformations. The effects of surface roughness, particle type and system history are discussed. The work analyzes the application of boundary-layer turbulence, especially the presence of quasi-periodic repeating patterns of coherent motion, to resuspension. Various mechanisms for generating the hydrodynamic force in turbulent and shear flows at different Reynolds numbers are discussed. Dimensionless expressions for hydrodynamic and surface forces and moments are developed allowing comparison and evaluation of their relative importance. Possible mechanisms of resuspension are proposed.