| The selection of diffusers used for room ventilation and cooling has been based on isothermal jet throw, but with the advent of colder supply air temperatures a more comprehensive methodology is needed because of the greater potential for jet separation and the difficulties mixing the room air with a lower supply volume. Standard diffuser selection tools are quite crude and do not consider factors such as jet buoyancy, enclosure effects, or the influences of heat sources.;The objective of this dissertation is to address these issues by applying computational fluid dynamic techniques to the problem of a negatively buoyant ceiling jet in a room with secondary convective flows induced by the room heat sources. The computations employ a k-;The localized loads change the mixing and spreading rate of the cold air jet, the room air flow patterns, and the separation behavior of the supply jet. Heat load location can influence the distance from the diffuser to the separation point by as much as a factor of two and should be considered, if possible, in the design of room air distribution systems. The technique developed in this dissertation for sizing diffusers provides acceptable ADPI. |
