A preliminary study on wind tunnel simulations of the explosive growth and dissipation of fine particulate matter in ambient air

摘要

This study, for the first time, investigated the explosive growth and dissipation of fine particulate matter (PM) in Nanjing based on simulations using a closed-circuit boundary-layer wind tunnel. The effects of relative humidity (RH) and liquid water content (LWC) on PM2.5 growth were examined. It was found that increasing moisture led to explosive growth of PM2.5 mass concentrations (average growth rate of 12.35 mu g/m(3).min) and the pollution levels. Winds were found to significantly aid the dissipation of fine PM, and high concentrations of fine PM only persisted for a very short time and dissipated after several hours. LWC was found to correlate more strongly with fine PM concentrations than did RH. This work underlines the effect of moisture on explosive growth in fine PM, and provides a new approach for the simulation of fine PM growth and dissipation in ambient air.