Numerical simulation of inter-floor airflow and impact on pollutant transport in high-rise buildings due to buoyancy-driven natural ventilation

Abstract

The purpose of this study is to numerically investigate vertical flow interaction and air pollutant transport in multiple adjoined ventilated enclosures. The flow is driven by buoyancy effect due to temperature/ concentration difference between the heat/pollutant sources and the ambient fluid. Attention was given to analyse the effect of the main factors – the strength of pollutant source, the presence of heat source and the strategies of window openings – on the pollutant transport among different enclosures. The study has found that air pollutant can spread from lower floors to upper floors due to the inter-floor airflow through open windows caused by the buoyancy force. The stronger the pollutant source, the higher the pollutant concentration would be in the adjacent apartments on upper floors. The results also show that the pollutant transport could be affected by the heat source, which would aid the transport of pollutants to upper floors when the heat source is located at the enclosure on the same floor as the pollutant source. The enclosure with two openings on single side would be more susceptible to the pollutants from the lower floor than an enclosure with one opening. The study concluded that the airflow interaction between different floors due to buoyancy has an important effect on the vertical transport of air pollutants in buildings.