Indoor coated particle resuspension due to human walking

A practical model was used for low density, silica-coated particle resuspension due to human walking. The foot stepping down and up processes were treated as the motion of an effective circular disk toward or away from a stationary surface. The squeezing flow or suction flow generated from the foot motions was assumed to be laminar and the corresponding gas velocity inside the foot was evaluated. The flow outside the foot was also evaluated based on the radial wall jet theory. The adhesion and drag forces exerted on particles were taken into account. The determination of critical radii for particle detachment was evaluated. The particle concentration and resuspension rate coefficients were also estimated. The results show that compared to Arizona Road Dust with same size, silica-coated particles show much larger resuspension rate coefficients.