Heat transfer augmentation using a rib-dimple compound cooling technique

Eun Yeong Choi, Yong Duck Choi, Won Suk Lee, Jin Teak Chung, Jae Su Kwak

Research output: Contribution to journalArticlepeer-review

106 Citations (Scopus)


Detailed distributions of the heat transfer coefficients in the channel with both angled ribs and dimples were measured using the transient liquid crystal technique. For comparison, heat transfer coefficients for dimpled and angle ribbed channels were also presented. The channel aspect ratio was designed to be 2 and 4 in order to simulate the internal coolant passage of a gas turbine blade. The rib pitch, rib angle, dimple diameter, and dimple center-to-center distance were 6 mm, 60°, 6 mm, and 7.2 mm, respectively. The Reynolds number based on the channel hydraulic diameter ranged between 30,000 and 50,000. Results show that the distribution of heat transfer coefficient was asymmetric due to the secondary flow induced by the angled ribs. Also, dimples fabricated between the ribs increased the heat coefficient with an acceptable increase in pressure drop. Thus, the compound cooling technique with angled rib sand dimples should be considered as a candidate for improving the heat transfer performance of a gas turbine blade internal cooling technique.

Original languageEnglish
Pages (from-to)435-441
Number of pages7
JournalApplied Thermal Engineering
Issue number1-2
Publication statusPublished - 2013

Bibliographical note

Funding Information:
This work was supported by a National Research Foundation of Korea grant funded by the Korean Government ( 2010-0016747 ).


  • Compound cooling
  • Dimple cooling
  • Gas turbine blade cooling
  • Internal cooling
  • Rib turbulated cooling

ASJC Scopus subject areas

  • Energy Engineering and Power Technology
  • Industrial and Manufacturing Engineering


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