Journal of Technology in Aerospace Engineering

Journal of Technology in Aerospace Engineering

Investigation of the Role of Convective Heat Transfer Coefficient Distribution in the Optimization ot Internal Cooling Passages of a Gas Turbine Blade

Document Type : Research Article

Authors
Amin valizade pasha 1
seyyed salman Norazar 1
Hamed Safikhani 2
1 Faculty of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran
2 Department of Mechanical Engineering, Faculty of Engineering, Arak University, Arak, Iran
10.22034/jtae.2026.10.3.1
Abstract
In this study, the geometry of internal cooling passages in a gas turbine blade is redesigned and optimized with the aim of reducing the maximum surface temperature. A three-dimensional coupled flow and heat-transfer model is solved in STAR-CCM+. To reduce computational cost, a hybrid approach combining single-variable optimization and the Taguchi method is used to determine the number, location, and diameter of the cooling holes, subject to non-interference constraints and a constant total coolant mass flow rate. The boundary conditions for the hot-gas and coolant streams are selected based on the experiments of Hilton et al. [24], and the Reynolds number is defined consistently with those laboratory conditions. Specifically, the external-flow boundary conditions are tuned to the experimental dataset in [24], with an inlet Mach number of approximately 0.16 and an inlet Reynolds number in the range (3.4–6.4) ×10^5, defined based on the axial chord and the true chord, respectively, in the validation dataset. The results show that increasing the number of holes from one to ten reduces the maximum surface temperature from 811.3 to 728.9K; however, the marginal temperature reduction decreases noticeably beyond six holes. Accordingly, a six-hole configuration is proposed as an industrially practical option, providing a 65 K reduction relative to the baseline case, improved thermal uniformity, and a more balanced coolant distribution. In addition, the external convective heat-transfer coefficient map over the blade surface is extracted and validated against experimental data, and then used to place holes more effectively in regions of high heat transfer
Keywords
Cooling channel geometry optimization
gas turbine blade
external convective heat transfer coefficient
Taguchi algorithm
convective heat transfer
Subjects
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Journal of Technology in Aerospace Engineering
Volume 10, Issue 3
Autumn 2026
Pages 1-16

  • Receive Date 18 February 2026
  • Revise Date 27 February 2026
  • Accept Date 12 May 2026
  • First Publish Date 06 June 2026