Computational Fluid Dynamics (CFD) modeling is effectively coupled with the experi-

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Air curtains are created in open refrigerated vertical display cases for creating an invisible barrier between the cold air inside and the warm air outside the case. A systematic approach is developed to minimize the entrainment and infiltration of warm air into the case by optimizing the performance of an air curtain through adjusting pertinent flow parameters and case geometry. A modular display case was manufactured for the parametric studies. In this modular display case the geometry and flow parameters were changed and the infiltration rate was measured using a new technique, tracer gas method, which could be performed noticeably faster than the conventional methods. This apparatus is referred to as the proof-of-concept air curtain (POCAC). A matrix of all possible permutations was constructed with the infiltration rate being the outcome of this matrix. This matrix was populated by actual experimental measurements as well as using validated Computational Fluid Dynamics (CFD) computer programs as a tool to acquire better resolution of the input and output datasets. All the problem variables are referred to as the input vector of all parameters that can be altered, and the output is the infiltration rate. An artificial neural network (ANN) program was used to provide the linkage between the input vector (problem variables) and the problem outcome (infiltration). This program can also be used by industry as a tool to estimate the infiltration rate for all existing open vertical display cases.

If you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information. About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation. AbstractPurpose -To address the effects of velocity profile at the discharge air grille (DAG) on the amount of entrained air into an open refrigerated display case (ORDC). Design/methodology/approach -The performance of an ORDC was studied by CFD, DPIV and LDV. The actual measured velocity profile at the DAG and total flow rate of the display case at its nominal operating conditions are used as guidelines throughout the CFD modeling. Findings -It was found that a skewed parabolic profile with the peak shifted towards the inner section of the case generates the minimum entrainment and demonstrates that with simple changes to the geometry of the DAG, a significant reduction in the entrainment rate could be achieved. Research limitations/implications -This study finds the optimum infiltration rate of a manufactured ORDC. A fundamental study is currently being done to address all the effective parameters that can affect the infiltration rate of any ORDCs. Originality/value -This paper presents this fact that the velocity profile at the DAG has a significant impact on the infiltration rate and electricity consumption of ORDCs. In turn, the velocity profile is dependent on the geometry and shape of the air passage before DAG. Thus, the analysis of the effect of the geometry on the velocity should seriously be taken into consideration by the case manufacturers.

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