Abstract
Particle dispersion in a room under stratum ventilation and under displacement ventilation have been investigated by numerical simulation. In addition, an experiment was carried out involving the newer stratum ventilation. The agreements between simulated velocity, temperature by the RNG k-ε turbulent model and the measured data were quite good. A discrete trajectory model was adopted to simulate the particle movement in a room. The results showed that the flow patterns created by different ventilation modes have great influence on the fates of particles. The particle concentrations for the entire room and for the breathing zone under stratum ventilation are less than that under displacement ventilation, which implies that the risk of particle inhalation under stratum ventilation is less than that under displacement ventilation. The deposited particle mass on room walls and furniture surfaces under stratum ventilation is greater than that under displacement ventilation. The particle mass deposited on the floor plays an important role in the process of particle deposition. The mass of particles that escaped under stratum ventilation was less than that under displacement ventilation. Moreover, the influence of particle diameter on particle dispersion is also considered in the present paper.