Investigation of particle resuspension from a garment using different turbulence dispersion models

Abstract

One of the most important sources of aerosol production in a controlled space is the human. The flow around the individual and the particles on the garment play an essential role in aerosol distribution in the environment. Such spaces are simulated from a Lagrangian or Eulerian point of view. In this research, particle resuspension from a user’s garment under horizontal and vertical unidirectional systems was studied. For this purpose, a computer program was developed and used for examination of the impacts of different particle turbulence dispersion models, such as Discrete Random Walk, in a controlled space. Moreover, the effects of flow direction, velocity, and particle density on the probability of resuspension of particles with different diameters were investigated. The results demonstrated that the vertical unidirectional system had advantages over its horizontal variant, and that increased flow velocity provided positive feedback in the vertical system but negative feedback in the horizontal one. In the horizontal system, the resuspension probability for the sizes of 5 and 0.5 microns has increased by 177 and 355 percent, respectively, compared to the vertical system. It is worth noting that the results of the isotropic and non-isotropic models for particles size below 5 microns were quite the same. For the particles size over 5 microns, the maximum percentage discrepancy of 138 in resuspension probability between the non-isotropic and isotropic models is obtained.

Keywords

• particle turbulence dispersion model
• particulate matter
• resuspension
• controlled space
• eulerian-lagrangian approach
• resuspension probability