Air flow characteristics of a room with square cone diffusers

Abstract

A computational fluid dynamics model with radiant exchange between surfaces is developed to examine the air flow characteristics of a room with square cone diffusers. As an input to the full-scale 3-D room model, a 2-D diffuser model that supplies direction and magnitude of air flow into the room is developed and evaluated using infrared visualization. The room air flow model is assessed using several previously documented problems with various geometries and boundary conditions. Simulations are conducted for heating and cooling of the room with one or two supply air diffusers. The results show that the offset and lips of the diffuser work together to determine the discharge air angles, which play an important role in determining the room air flow patterns. For a certain discharge angle in the heating case, the air flows along the ceiling. The results indicate that, for the same supply air flow, operating only a single diffuser initiates more mixing of the room air flow, which results in enhanced temperature uniformity compared to that for two diffusers. Radiant exchange between the exterior window and interior surfaces causes a significant change in the window temperature. © 2004 Elsevier Ltd. All rights reserved.