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Article
Jet Entrainment Rate in Air Curtain of Open Refrigerated Display Cases
International Journal of Refrigeration
  • Homayun K. Navaz, Kettering University
  • Brenda S. Henderson
  • Ramin Faramarzi
  • Ahmad Pourmovahed, Kettering University
  • Frederic Taugwalder
Document Type
Article
Publication Date
3-1-2005
Abstract

Experimental and computational methods are used to address those parameters that have significant effects on the amount of entrained (warm) air in an open refrigerated display case. These parameters are identified, quantified, and the rate of entrainment is expressed as a function of these parameters. It is found that the turbulence intensity, the shape of the mean velocity profile at the discharge air grill, and the Reynolds number are mainly responsible for the amount of entrained air in a display case. It is also concluded that lower Reynolds numbers will reduce the amount of the entrained air in the display case, however, the trade off will be higher temperature of the food products on shelves. Digital particle image velocimetry (DPIV) was used to map the entire mean velocity flowfield and the turbulence intensity. The laser doppler velocimetry technique was also used to verify the mean velocity and turbulence intensity measurements made by DPIV. The results indicated an excellent agreement between both methods. Parametric studies for the rate of entrainment of the outside air into the display case were performed using a computational fluid dynamics tool. The results indicate that lowering the Reynolds number of the air curtain reduces the entrainment rate. However, sufficiently high momentum should still exist to enforce the integrity of the air curtain structure.

DOI
https://doi.org/10.1016/j.ijrefrig.2004.08.002
Rights

© 2004 Elsevier Ltd.

Citation Information
Homayun K. Navaz, Brenda S. Henderson, Ramin Faramarzi, Ahmad Pourmovahed, et al.. "Jet Entrainment Rate in Air Curtain of Open Refrigerated Display Cases" International Journal of Refrigeration Vol. 28 Iss. 2 (2005) p. 267 - 275 ISSN: 0140-7007
Available at: http://works.bepress.com/ahmad-pourmovahed/1/