Numerical analysis of particle behaviors in indoor air using Lagrangian method

As particles in room air can cause lung diseases, it is important to study how they are transported and dispersed in buildings. This investigation numerically studied particle dispersion by using the Lagrangian approach. The turbulent airflow is solved by the RNG k-e model; and a discontinuous random walk (DRW) model is applied to account for the stochastic effect of particle movement in turbulent flow. The computed results agree reasonably well with the experimental data for particle dispersion in a wind tunnel. This paper also studied particle dispersion in a floor displacement ventilated room. Results showed that particle movement may be very different from the airflow pattern, and a high exposure risk of the occupants to particles has been found when they are generated in a recirculation area.