Numerical modelling is performed for three-dimensional turbulent buoyant flows emerging from an air diffuser in an air-conditioned, ventilated room. The velocity and temperature distributions of air in the room are calculated, and the calculated results are found to be in reasonable agreement with published experimental observations. Calculations of Air Diffusion Performance Index (ADPI) for a sidewall grille are carried out for different flow rates of air supply. The predicted ADPI values are found generally to be consistent with the corresponding experimental values.
A new visual method is yielded by a particular application of Mollier's h,x-diagram. Point fields (temperature and humidity) lead to a significant improvement upon previous graphic methods. Flats with mechanical balanced ventilation are drier and more influenced by the exterior climate than are with shaft ventilation system ventilated flats ("Berlin ventilation"). The evaluation of the graphic representation of the experimental results in the form of curves permits rapid assessment of the experimental results.
It is particularly important to be aware of the air flow pattern in a building when determining indoor air quality problems or calculating space conditioning loads for energy consumption. Correct sizing of space conditioning equipment is also dependent upon accurate air flow information. A number of infiltration models have been developed to calculate infiltration-related energy losses and the resulting air flow distribution in both single-zone and multizone buildings.
Contains a brief description of 14 mathematical models of air infiltration with bibliography of relevant papers. The theory behind mathematical modelling is outlined and the advantages and disadvantages of the various types of models are described. Comments are given on the range of applicability of the models reviewed. (Out of Print)
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