Paper Conference

Proceedings of Building Simulation 2011: 12th Conference of IBPSA


Large-eddy simulation of indoor dispersion of expiratory aerosol

Takamasa Hasama

Abstract: This paper presents the decay characteristics of expiratory aerosol in indoor large-eddy simulations (LES) coupling with Lagrangian particle tracking in terms of preventing ability evaluation to the pathogen infection in a typical indoor environment. A Lagrangian method, which is able to simulate water droplet behaviour with seven particle diameters, was adopted simultaneously. Five enclosed-room cases with different diffuser-induced airflow patterns were investigated, all under the same air change per hour (ACH) condition. In particular, we focus on the decay characteristics of a typical office environment, unlike hospital isolation rooms to control airborne spores. The results show that for particles about 10.0 pm in diameter, which closely approximates the mean diameter of expiratory aerosol generated when coughing or speaking, the decay characteristics of the floor-supplied displacement type proved most efficient, followed by the ceiling-mounted breezeline diffuser, third is the floor-mounted diffuser, fourth is the ceiling-mounted square diffuser, and least effective was the ceiling-mounted four-way cassette-type HVAC unit, under the same ACH.
Pages: 1966 - 1972