A Study of Particle Deposition in Ventilation Ducts with Convex or Con-cave Wall Cavity

Abstract

This article numerically investigates particle deposition in the ventilation ducts with convex or concave wall cavity. The utilized models can accurately reproduce the related data in the previous studies. Characteristics of the airflow and particles tracks are also investigated. Compared with that in the smooth duct, the particle deposition velocity increases greatly in the ducts with various wall cavities. Mechanisms of the enhancement of particle deposition are further analyzed. The interception by the cavities, the expanded deposition area, and the enhanced flow turbulence are conducive to the particle deposition. Ventilation ducts with convex/concave wall cavity can be considered as an efficient method to reduce PM2.5. In addition, Vd+ increases more quickly in the duct with the convex cavity than that with the concave cavity.