| In recent years, indoor air quality has gained more and more attention as people begin to realize that indoor air quality is very important to their health and comfort. In this study, the investigation of indoor airflows in a full-scale ventilated room was conducted using two approaches: experimental measurements and numerical simulations.;The Volumetric Particle Streak-Tracking Velocimetry (VPSTV) was used to measure the three spatial components of air velocities in a full-scale room at three ventilation rates: 3 ACH, 8.6 ACH and 19.5 ACH (Air Change Per Hour). It was observed that one primary central recirculation vortex was formed in the middle of the room and one secondary small vortex existed near the left bottom corner. The sizes and positions of the two vortices varied with the ventilation rates: the central vortex became fuller and moved towards the center of the room with increasing ventilation rates; on the other hand, the secondary vortex became smaller and moved toward the left bottom corner. The reattachment length and jet penetration measured at seven different ventilation rates ranging from 3 ACH to 100 ACH showed a strong dependence on the ventilation rates and became relatively constant once the ventilation rate reached a threshold value of 19.5 ACH.;Different turbulence models based on the Reynolds-Averaged Navier-Stokes (RANS) method and the Large Eddy Simulation (LES) with dynamical subgrid model were evaluated with the experimental data from the VPSTV measurements. The LES provided the best predictions for the three ventilation rates while RSM predictions were closest to measurements among the RANS models. The results from LES at seven different ventilation rates ranging from 0.1 ACH to 27.9 ACH showed that airflows inside the room were fully developed when the ventilation rates were equal or higher than 19.5 ACH. This was demonstrated by use of the maximum velocities decaying along the ceiling and the floor, flow topologies (including flow patterns, separation and reattachment points, positions of vortices, etc.), vorticity and turbulent kinetic energy spatial distributions. In addition, the maximum velocity decay and the airflow boundary layer growth along both the ceiling and floor behaved like those of plane turbulent wall jets as proposed by other studies. |
