The investigation of groove geometry effect on heat transfer for internally grooved tubes

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Bilen K., Çetin M., Gul H., Balta T.

APPLIED THERMAL ENGINEERING, vol.29, pp.753-761, 2009 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 29
  • Publication Date: 2009
  • Doi Number: 10.1016/j.applthermaleng.2008.04.008
  • Journal Name: APPLIED THERMAL ENGINEERING
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.753-761
  • Keywords: Grooves, Ribs, Grooved tube, Heat transfer enhancement/augmentation, Convective heat transfer, Heat exchanger, SPIRALLY CORRUGATED TUBES, TURBULENT-FLOW, PRESSURE-DROP, TRANSFER COEFFICIENT, FRICTION, CONDENSATION, ENHANCEMENT, PERFORMANCE, TRANSVERSE, CHANNELS
  • Ataturk University Affiliated: Yes

Abstract

An experimental study of surface heat transfer and friction characteristics of a fully developed turbulent air flow in different grooved tubes is reported. Tests were performed for Reynolds number range 10,000-38,000 and for different geometric groove shapes (circular, trapezoidal and rectangular). The ratio of tube length-to-diameter is 33. Among the grooved tubes, heat transfer enhancement is obtained up to 63% for circular groove, 58% for trapezoidal groove and 47% for rectangular groove, in comparison with the smooth tube at the highest Reynolds number (Re = 38,000). Correlations of heat transfer and friction coefficient were obtained for different grooved tubes. In evaluation of thermal performance, it is seen that the grooved tubes are thermodynamically advantageous (Ns, a < 1) up to Re = 30,000 for circular and trapezoidal grooves and up to Re = 28,000 for rectangular grooves. It is observed that there is an optimum value of the entropy generation number at about Re = 17,000 for all investigated grooves. (C) 2008 Elsevier Ltd. All rights reserved.