Dynamic simulation of contaminant inleakage produced by human walking into control room

Abstract

Human walking-induced transport can be a significant mechanism during entry from a contaminated region into a protective enclosure, such as a control room. The passage through the door gives the outside air the opportunity to leak into the control room, endangering the staff inside. The objective of this study is to simulate contaminant transport induced by human walking motion in simplified situations – the person moving from the corridor into the anteroom, with various entrance times (from 2 to 8s). The CFD simulations were made by using the RANS solver with dynamic meshes techniques. The inleakage airflow through the doorway and the inleakage air volume can be both quantified with tracer gas measurements. The simulation results illustrated that the whole inleakage process can be divided into four stages: door draws in air; person entrains the air; door closing cuts short the wake; and door pushes the air in the final movement. It was found that the total inleakage volume is affected by the entrance time, and can be as much as 1.192m3 for an 8.0s entrance time. The data measured in our previous experimental study were employed to validate with the simulation result. The comparison result indicated an agreement when the entrance time was 3–8s, but as the entrance time increased, the simulation values were significantly higher than those measured experimentally. The simulation results can therefore be considered as a conservative estimate, which can guide the prevention of inleakage in future engineering applications.