Scientific Research and Essays

  • Abbreviation: Sci. Res. Essays
  • Language: English
  • ISSN: 1992-2248
  • DOI: 10.5897/SRE
  • Start Year: 2006
  • Published Articles: 2755

Full Length Research Paper

Effects of holes placed on perforated finned heat exchangers at different angles on the Nusselt and Reynolds numbers

Gulay Yakar* and Rasim Karabacak
Department of Mechanical Engineering Pamukkale University, 20070 Kinikli, Denizli, Turkey.
Email: [email protected]

  •  Accepted: 17 December 2009
  •  Published: 31 January 2010

Abstract

In this study, 6 mm diameter holes were opened on each circular fin on a heating tube in order to increase convective heat transfer. This is different from other studies in the literature. These holes were placed on the circular fins in such a way as to follow each other at the same chosen angle. The holes created turbulence in a region near the heating tube surface on the bottom of the fin. Experiments were performed to analyze the effect of this turbulence on heat transfer and pressure drop. These experiments were performed at six different angular positions in order to determine the best angular positioning. In addition, a perforated finned heater was compared with an imperforate finned heater to observe the differences. When Nud values were considered for the same air flow rate and the same , the Nudvalue of the heater with holes was found to be 2.43% higher than the Nuvalue of the heater without holes. However, there was a 3.84% decrease in pressure.

 

Key words: Heat exchanger, heat transfer, convection.