Large eddy simulation and zonal modeling of human-induced contaminant transport

An immersed boundary method for particulate flow in an Eulerian framework is utilized to examine the effects of complex human motion on the transport of trace contaminants. The moving human object is rendered as a level set in the computational domain, and realistic human walking motion is implemented using a human kinematics model. A large eddy simulation (LES) technique is used to simulate the fluid and particle dynamics induced by human activity. Parametric studies are conducted within a Room-Room and a Room-Hall configuration, each separated by an open doorway. The effects of the average walking speed, initial proximity from the doorway, and the initial mass loading on room-to-room contaminant transport are examined. The rate of mass transport increases as the walking speed increases, but the total amount of material transported is more influenced by the initial proximity of the human from the doorway. The Room-Hall simulations show that the human wake transports material over a distance of about 8 m. Time-dependent data extracted from the simulations is used to develop a room-averaged zonal model for contaminant transport due to human walking motion. The model shows good agreement with the LES results.