Hydrogen combustion effects on turbine vane aerodynamics and heat transfer

초록

Hydrogen-fueled gas turbines experience changes not only in the combustion chamber but also in turbine aerodynamics and heat transfer, owing to differences in combustion products. Variations in the thermophysical properties of the combustion gases, which serve as the working gas in the turbine section, can modify the aerodynamic and thermal response of turbine components. In this study, a coupled combustion and computational fluid dynamics framework was employed to investigate the effects of hydrogen combustion on turbine-side aerodynamics and heat transfer under fixed energy input and turbine inlet temperature constraints. Combustion gas properties corresponding to varying hydrogen blending ratios were obtained from combustion simulations, revealing reduced density and increased specific heat and thermal conductivity, along with a decrease in the mass flow rate entering the turbine section. Based on these working gas conditions, the aerodynamics and heat transfer characteristics of the NASA C3X turbine vane were analyzed. The hydrogen combustion gases exhibited weaker expansion through the vane passage, resulting in higher downstream pressure and reduced pressure loading, which were accompanied by decreases in lift and drag coefficients and in total pressure loss. Dynamic pressure normalization effectively distinguished density-driven aerodynamic scaling, while the normalized aerodynamic characteristics remained largely unchanged. Meanwhile, the heat transfer coefficient increased because of altered thermal properties, with a localized enhancement near the suction peak associated with thermal boundary layer compression. These results show that hydrogen combustion moderately modifies turbine aerodynamics and heat transfer, highlighting the importance of turbine-side investigations of hydrogen gas turbines.

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