Direct numerical simulation of contaminant removal in presence of underfloor air distribution system.

Indoor contaminant removal over 0.5 ≤  ≤ 5.0, 0.5 ≤  ≤ 5.0, and 50 ≤  ≤ 500 was investigated numerically, wherein refers to the Froude number, refers to the buoyancy ratio, and Re refers to the Reynolds number. As demonstrated, the ventilation effectiveness increased with increasing contaminant source intensity and air supply intensity at a constant air temperature, indicating that increase the fresh air can effectively eliminate contaminants in this case. At high air supply temperatures, the heat retention time and contaminant transport was extremely short, and the fresh air induced by strong natural convection floating lift was rapidly discharged. Additioanlly, the air supply intensity had significant effects on contaminant removal. Quantification of the ventilation effectiveness under the combined effects of air supply intensity, air supply temperature and contaminant source intensity was determined based on the results of direct numerical simulations.