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Large Eddy Simulation of Particle Resuspension During a Foot Step
Choi, J., J. R. Edwards, J. A. ROSATI, AND A. D. Eisner. Large Eddy Simulation of Particle Resuspension During a Foot Step . AEROSOL SCIENCE AND TECHNOLOGY. Taylor & Francis, Inc., Philadelphia, PA, 46(7):767-780, (2012).
Re-suspension of particulate matter by human activity can have a significant impact on particle concentrations in indoor environments. The removal of surface-bound particulates as a person’s foot contacts a substrate and the subsequent transport of such particulates through wake entrainment effects and through deposition is an important mechanism for particle dispersion. To study aspects of this event, we perform high-fidelity simulations of particle transport due to the heel-to-toe contact of a foot with a particle-laden carpet. For this purpose, an immersed boundary method is extended to account for particle transport, re-suspension and deposition near the surface of the foot. Particle deposition is modeled as a combination of gravitational settling, Brownian diffusion and convective impaction, while a dynamic re-suspension model is used to model particle re-suspension from the surfaces. We demonstrate details of transient transport phenomena of re-suspended particles during a heel-to-toe foot-motion event. The effects of the thickness of carpet layer, the foot penetration depth into the carpet layer, the foot speed, and particle sizes on the mass re-suspended are investigated. Parametric studies show that a deeper foot penetration into a thinner carpet layer increases particle re-suspension and a faster foot motion also increases the re-suspension. Particles in a size range of 1−10m have higher re-suspension rates than larger particles (20m) as the latter are more affected by gravitational settling. Predicted re-suspension rates are compared with those obtained in recent experiments.
Record Details:Record Type: DOCUMENT (JOURNAL/PEER REVIEWED JOURNAL)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL HOMELAND SECURITY RESEARCH CENTER
DECON AND CONSEQUENCE MANAGEMENT DIVISION