Share

Enhancement of laminar and transitional flow heat transfer in tubes by means of wire coil inserts.

Author(s) : GARCÍA A., SOLANO J. P., VICENTE P. G., et al.

Type of article: Article

Summary

This work presents an extensive experimental study on three wire coils of different pitch inserted in a smooth tube in laminar and transition regimes. Isothermal pressure drop tests and heat transfer experiments under uniform heat flux conditions have been carried out. The friction factor increases lie between 5 and 40% in the fully laminar region. The transition from laminar flow to turbulent flow is continuous, without the instabilities and the pressure drop fluctuations that a smooth tube presents. At Reynolds numbers below 200, wire coils do not enhance heat transfer with respect to a smooth tube. For Reynolds numbers between 200 and 1000, wire coils remarkably increase heat transfer. At Reynolds numbers above Re about 1000-1300, transition from laminar to turbulent flow takes place. At Reynolds number around 1000, wire inserts increase the heat transfer coefficient up to eight times with respect to the smooth tube. A performance comparison between wire coils and twisted tape inserts has shown that wire inserts perform better than twisted tapes in the low Reynolds number range: Re= 700-2500. [Reprinted with permission from Elsevier. Copyright, 2007].

Details

  • Original title: Enhancement of laminar and transitional flow heat transfer in tubes by means of wire coil inserts.
  • Record ID : 2007-1972
  • Languages: English
  • Source: International Journal of Heat and Mass Transfer - vol. 50 - n. 15-16
  • Publication date: 2007/07

Links


See other articles in this issue (10)
See the source

Indexing