Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5752873 | Atmospheric Environment | 2017 | 24 Pages |
Abstract
Studying the scavenging of aerosol particle by drops has been a key topic of atmospheric science since the late seventies, given its relationships with atmospheric depollution, with the physics of clouds and precipitations and with global warming. However, the efficiency with which falling droplets capture aerosol particles is still imprecisely known for a wide range of drop Reynolds number, Weber numbers, aerosol particles inertia and Brownian Schmidt number. In this paper, microphysical modeling is used to compute precisely the drop collection efficiency for aerosol particles around the Greenfield gap which are submitted to both drag force and Brownian motion, for droplets falling in quiescent air at moderate Reynolds number (Redâ¤100). Depending on the impactional or diffusional parameters, the collection regions on the drop surface are highlighted. The results are then compressed by a correlation which extends the field of use of the theoretical model of Wang et al. (1978) by taking inertial capture into account. The proposed correlation is suitable to estimate the aerosol scavenging efficiency for a non-evaporating, non-deforming drop with Redâ¤100 and particle Stokes number Stpâ[0;+â]. In case of evaporating or condensing droplets, the effect of thermophoresis and diffusiophoresis are also taken into account through an extension of the formulation proposed by Wang et al. (1978) and hence with similar accuracy.
Keywords
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Atmospheric Science
Authors
Gaël Cherrier, Emmanuel Belut, Fabien Gerardin, Anne Tanière, Nicolas Rimbert,