Directional Effects of Human and Door Motions on the Transport of Aerosols Across a Doorway

Human movement across a doorway and associated door opening and closing motions is an important mechanism of containment failure in protective rooms. Detailed information regarding the 3D, time‐dependent air flow field and aerosol concentration field induced by the motions is of pivotal importance for the development of effective intervention strategies. This study used boundary‐conformal moving mesh techniques to simulate air and aerosol transport from a contaminated room into a pressure‐equilibrium clean room. The simulations were conducted with different directions of manikin movement and door swinging in order to analyze their individual and combined effects on aerosol transport. The results showed that the net transport of air was dominated by the door swinging motion. The volume of air exchange caused by an opening door was around 47% of the volume displaced by the door as it swinged open, while the passage of a human‐sized manikin across the doorway only added a few small fluctuations (< 10%) in the curve of air exchange rate. The net transport of aerosol was always associated with an outward motion, either an out‐swinging door or an out‐moving manikin from the contaminated room toward the clean room. An out‐swinging door caused 44% of the aerosols in a volume equal to the displaced volume near the door to escape, with a further 28% added by an out‐moving manikin. Comparatively, the amount of aerosol escape induced by an in‐swinging door or in‐moving making was very small. The study revealed that the vortex flows in the wake regions played a key role in aerosol transport, therefore proposing that destroying the wake flow regions of out‐moving objects may be an effective method to mitigate containment failure induced by swinging doors and moving human occupants.