Air-side heat transfer enhancement of a refrigerator evaporator using vortex generation

A. D. Sommers, A. M. Jacobi

Research output: Contribution to journalArticlepeer-review


In most domestic and commercial refrigeration systems, frost forms on the air-side surface of the air-to-refrigerant heat exchanger. Frost-tolerant designs typically employ a large fin spacing in order to delay the need for a defrost cycle. Unfortunately, this approach does not allow for a very high air-side heat transfer coefficient, and the performance of these heat exchangers is often air-side limited. Longitudinal vortex generation is a proven and effective technique for thinning the thermal boundary layer and enhancing heat transfer, but its efficacy in a frosting environment is essentially unknown. In this study, an array of delta-wing vortex generators is applied to a plain-fin-and-tube heat exchanger with a fin spacing of 8.5 mm. Heat transfer and pressure drop performance are measured to determine the effectiveness of the vortex generator under frosting conditions. For air-side Reynolds numbers between 500 and 1300, the air-side thermal resistance is reduced by 35-42% when vortex generation is used. Correspondingly, the heat transfer coefficient is observed to range from 33 to 53 W m-2 K -1 for the enhanced heat exchanger and from 18 to 26 W m -2 K-1 for the baseline heat exchanger.

Original languageEnglish (US)
Pages (from-to)1006-1017
Number of pages12
JournalInternational Journal of Refrigeration
Issue number7
StatePublished - Nov 2005


  • Air
  • Display cabinet
  • Domestic refrigeration
  • Evaporator
  • Finned tube
  • Heat transfer
  • Improvement
  • Vortex

ASJC Scopus subject areas

  • Building and Construction
  • Mechanical Engineering


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