Numerical Study on the Effect of Air Diffuser Angle on the Flow Field and Contaminant Dispersion in a Ventilated Room

Due to increasing application of air conditioning systems in various industries including cleanrooms, the optimized use of the applied equipment for less energy consumption and better contaminant distribution is essential. This paper investigates the effect of four-way ceiling diffuser angle effect on the ventilation system performance numerically using Eulerian-Lagrangian approach. In this study, the initial contaminant distribution is assumed to be uniform in the ventilated space and the room assumed to be without diffuser and with diffusers of 30, 90 and 30-90 blade angles is investigated. This work shows that the diffuser with 30 and 30-90 blade angles decrease the contaminant faster than 90° and without blade configurations. It is also shown that the 90° diffuser and without diffuser cases which shoot air vertically leads to less deposition and higher exit to deposition ratio. Based on flow field pattern, the flow field of cases with 30 and 30-90 degree could sweep particles from corners of the room better than W/O diffuser and 90° cases while their flow field role is less in sweeping corners and the main role is on central locations.