Session: Student Poster Competition

Submission Number: 187143

Heat Transfer Characteristics of Additively Manufactured Pin-Fins With Flow-Guiding Structures for Enhanced Turbine Vane Trailing-Edge Cooling 

Turbine inlet temperature has steadily increased to improve gas-turbine thermal efficiency. Consequently, thermal loads on hot-section components such as blades and vanes continue to rise, making effective cooling essential for reliable operation. Among these components, the trailing edge is particularly vulnerable to heat penetration because its thin geometry is dictated by aerodynamic requirements, leading to a higher risk of thermal damage than other regions. Pin-fin arrays are therefore widely used in trailing-edge cooling passages to enhance heat transfer; however, conventional pin-fin designs face limitations under increasingly severe thermal environments. In pin-fin channels, endwall heat transfer can be elevated upstream of a pin by horseshoe vortices, whereas relatively low heat transfer often persists downstream due to wake formation.

In this study, a flow-guiding structure was integrated with pin-fins to (i) accelerate the near-wall flow upstream of each pin and (ii) mitigate downstream wake effects, thereby enhancing endwall heat transfer both upstream and downstream of the pins. Heat transfer and flow characteristics were quantified and compared with those of a baseline pin-fin configuration. Both cases were evaluated at H/D = 2. Local endwall heat transfer was obtained using the naphthalene sublimation method (heat/mass transfer analogy) over Re = 10,000–30,000 using scaled-up pin-fin specimens. In addition, full-scale metal AM specimens were tested to assess the integrated thermal performance including both convection and conduction, with the convective heat conductance (hA) reported over Re = 7,500–17,500. Flow physics were analyzed using ANSYS CFX 2022R2 with an approximately 18 million-cell structured hexahedral mesh and y⁺ < 1, under conditions matched to the naphthalene experiments.

The naphthalene sublimation results showed that the guide-integrated pin-fins increased endwall heat transfer by up to ~78% relative to the baseline, attributed to guide-induced upstream acceleration and downstream wake control. In the metal AM tests, the increased heat-transfer area provided by the guide further increased hA by up to ~92%. Moreover, at Re = 15,000, the heat transfer per unit pumping power (based on pressure-loss-derived pumping power) improved by 8.42% compared with the baseline.

Overall, the AM-enabled flow-guide–integrated pin-fin concept (at H/D = 2 and within the present Reynolds-number range) enhances endwall heat transfer while improving thermal-hydraulic performance, providing a practical design option for strengthening turbine vane trailing-edge thermal integrity.

Presenting Author: Gyeongryun Kim Yonsei University

Presenting Author Biography: Gyeongryun Kim is a Ph.D. candidate in the Heat Transfer Laboratory at Yonsei University, Seoul, Republic of Korea. His research focuses on internal and external cooling technologies for gas turbine blades and vanes.

Authors:

Gyeongryun Kim Yonsei University
Jaehyeong Kim Yonsei University
Hee Jae Lee Yonsei University
Ho Seop Song Yonsei University
Chang Yong Lee Doosan Enerbility
Hyung-Hee Cho Yonsei University