Session: 12-03: Film Cooling Computational Studies (I)

Paper Number: 153185

Effect of Hydrogen Combustion on Film Cooling Characteristics in Gas Turbines 

This study numerically investigates the effect of hydrogen blending combustion on the film cooling performance at the turbine side. Hydrogen combustion in the gas turbine not only changes the combustion characteristics but also impacts the thermophysical properties of the flue gas, resulting in altered aerodynamics and heat transfer at the turbine stage. By combining numerical analyses of combustion and flow fields, the effect of hydrogen blending on turbine-side film cooling was revealed. This study utilized a spanwise-scaled version of the C3X linear cascade model to investigate the film cooling effectiveness using RANS simulations. The key film cooling parameters investigated were blowing ratio and pressure ratio, which were compared across the full range of hydrogen blending ratios (HBR). Due to the altered flue gas composition induced by hydrogen combustion, carefully chosen mixing rules indicated that mainstream density decreased while specific heat capacity increased with increasing HBR. As film cooling is sensitive to mainstream conditions, these changes affected coolant behavior, including coolant trajectory and heat transfer. The dominant flow phenomenon influencing film cooling performance was coolant liftoff caused by reduced mainstream density. The analysis revealed relatively small differences on the suction side, and for both blowing ratio and pressure ratio variations, the suction side was less prone to liftoff due to the highly accelerated mainstream. As a result, area-averaged film cooling effectiveness gradually decreased with increasing HBR. From these results, it can be concluded that film cooling efficiency slightly degrades when the gas turbine operates with higher HBR, necessitating a more sophisticated cooling design for hydrogen gas turbines.

Presenting Author: Yoonhyeong Jeong Korea University

Presenting Author Biography: Yoonhyeong Jeong is a Ph.D. student in the Computational Fluid Dynamics Lab at Korea University. He holds a bachelor's degree in Mechanical Engineering from Chung-Ang University, Korea, and is currently pursuing his Ph.D. degree. His research focuses on the aero-thermal characteristics of gas turbines, including performance, aerodynamics, and cooling performance. Yoonhyeong has authored and co-authored several papers related to gas turbine film cooling and hydrogen combustion in gas turbines. He is particularly interested in the effect of hydrogen combustion on turbine performance. Beyond his specific research focus, he actively engages in solving gas turbine-related engineering problems using numerical methods, leveraging both commercial software as well as in-house and open-source code.

Authors:

Yoonhyeong Jeong Korea University
Duy-Tan Vo Korea University
Jaiyoung Ryu Korea University