AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Identifying the Indoor Particle Resuspension Mechanism for Human Walking
KYUNG SUL, Iman Goldasteh, Pooya Kabiri, Douglas Bohl, Goodarz Ahmadi, Andrea R. Ferro, Clarkson University
Abstract Number: 401 Working Group: Indoor Aerosols
Abstract Resuspension of settled particles via human walking is known to be a significant source of indoor particulate matter (PM). Previous studies found that resuspension rates from carpet are higher than those from hard floorings. However, the reason is not fully understood. In this paper, airflows around a shoe for different types of floorings were studied in order to understand the differences in the associated aerodynamics. A mechanical foot experimental setup was used as a standardized resuspension device to study the resuspension mechanism during the gait cycle. The device replicates the motion of the shoe during the walking, and repeats identical cycles so that the data are reproducible. Particle image velocimetry (PIV) was used to evaluate the instantaneous airflow around the shoe during the gait cycle. Olive oil was used to seed airflow for PIV measurements. A plane of particle-laden airflow around the shoe was illuminated by a laser light sheet and consecutive images of the plane were captured while the mechanical foot device was operating. Synchronization and phase averaging approach were used for generating the instantaneous airflow velocity for different shoe configurations in the gait cycle. The PIV experiments were conducted for two types of floorings (hard flooring and carpet). The resulting airflow velocities were compiled and analyzed and the effects of different floorings were studied. In addition, a three dimensional computational model of the airflow around the shoe was developed using the FLUENT$^(TM) computational fluid dynamics (CFD) package. A RANS approach with the RNG k-epsilon turbulence model was used for simulating the airflow field during the gait cycle. The induced airflow during the shoe motion was investigated numerically using the dynamic mesh approach. The PIV data for different case were compared with the CFD model results, and good agreement was found.