Radiation influence mechanism and coupled heat transfer characteristics of turbine blades in hydrogen fuel environment

Aircraft engines fueled by hydrogen are considered a promising solution for future aviation, owing to their zero carbon emissions, high energy density, and sustainable sourcing. However, hydrogen combustion occurs at higher temperatures than conventional hydrocarbon fuels and produces exhaust gases rich in water vapor (a strong radiative participant). These conditions markedly intensify the radiative heat load on turbine blades, fundamentally altering the heat transfer characteristics and imposing unprecedented cooling challenges. This study investigates the radiation effects on heat transfer and cooling characteristics in turbine blade under hydrogen combustion. Results found that: in the gas core region, the net radiative flux divergence strongly depends on fuel type and combustion products. The highest net radiative flux divergence occurs under hydrogen combustion with high H 2 O concentration, and a reduction in H 2 O content leads to a corresponding decrease in net radiative flux divergence. The increase in Nu is most significant under hydrogen combustion conditions. In contrast, Nu increases are relatively modest in kerosene and pure air environments. In the case with a 35% H 2 O volume fraction, the radiation-induced Nu increase is approximately 15, while the average cooling effectiveness decreases by 0.079, which corresponds to 24.68% of the average cooling effectiveness in the absence of radiation. This decrease is 3.66% and 13.59% higher than those observed under aviation kerosene and pure air conditions, respectively. As an additional energy transfer mechanism, radiation homogenizes the temperature field and mitigates local temperature gradients.