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Measurements of infiltration through different size entrances of a cold store at two different cold store temperatures were taken and compared against established analytical models and computational fluid dynamics (CFD) models. The analytical and CFD models generally tended to over predict the infiltration. The analytical model developed by Gosney et al provided the closest comparison with the various experiments. The CFD models were more accurate than the fundamental analytical models but less accurate than those based on a semiempirical approach. For the experimental configurations examined, CFD offered no real advantage over these empirical analytical models. If the conditions were such that the infiltration rate changed with time or if door protection devices (e.g. air curtains) were used, CFD would become much more advantageous in predicting infiltration.

The aim of this study was to compare the measured effectiveness of an air curtain device at different jet velocities against a three-dimensional (3-D) computational fluid dynamics (CFD) model. The air curtain device was not as wide as the entrance and had a geometry that encouraged 3-D flow. By carefully setting up the air curtain an effectiveness of 0.71 was achieved compared to the initial value of only 0.31 as set by the air curtain device installer. The 3-D CFD model predicted the infiltration through the entrance with no air curtain to an accuracy of within 20-32%. The predicted effectiveness, E, of the air curtain at different jet velocities was 0.10-0.15 lower than measured. The shape of the effectiveness curve against jet velocity was well predicted. CFD has shown that the flow from this air curtain cannot be considered as 2-D. The central part of the jet is deflected away from the cold store by the Coanda effect caused by the air curtain device's fan body. The edges of the jet are deflected into the cold store by the stack pressures and turn into the void caused by the deflected central jet. (c) 2006 Elsevier Inc. All rights reserved

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