Jet entrainment minimization in an air curtain of open refrigerated display case

Purpose - 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.