Session: Poster Session

Paper Number: 151743

Effect of U-Shaped Pedestal on Overall Cooling Effectiveness in Double Wall Impingement/effusion Cooling 

The thermal efficiency of a gas turbine increases as the turbine inlet temperature increases, which is why cooling technologies for gas turbine systems have been developed for decades. The impingement/effusion cooling method is a highly effective cooling system that integrates array impingement jet cooling with effusion (film) cooling Since double wall cooling is proposed as an advanced thermal design for gas turbine blades, impingement/effusion cooling is adjusted on blades with improved cooling designs. The present study investigates the effects of U-shaped pedestal in double wall structured impingement/effusion cooling systems on overall cooling effectiveness. Double wall configuration includes two perforated walls, specifically a jet wall and an effusion wall, which feature a staggered hole arrangement. The diameter of the hole (d) is 5 mm, the Reynolds number of the jet is 3,000, and the blowing ratio between the secondary coolant and mainstream is 0.3. The gap between two walls is defined by a 1d, and the wall thicknesses of the effusion and jet walls are 2.4d and 1d, respectively. The U-shaped pedestals have been used to support wall gap and induce conduction effects for actual turbine components. A numerical analysis was performed using SST turbulence model in the commercial CFD program Ansys CFX 2022 R2 to investigate the overall cooling effectiveness. The results suggest that the U-shaped pedestals lead to an increase in overall cooling effectiveness by enhancing the conduction effect and the impingement jet heat transfer on the stagnation region. This results in an overall cooling effectiveness on the external surface of effusion wall that is approximately 20% higher than the baseline.

Presenting Author: Yumin Kim Yonsei University

Presenting Author Biography: Ph.D. student

Authors:

Yumin Kim Yonsei University
Gyeongryun Kim Yonsei University
Hee Jae Lee Yonsei University
Jeonghun Heo Yonsei University
Hyung Hee Cho Yonsei University