Influence of gas thermal radiation on heat transfer characteristics of different cooling structures

In aero-engines, as the pre-turbine temperature continues to rise, radiation effects become increasingly prominent, and the proportion of radiation heat flux in the total thermal load of high-temperature components keeps increasing—posing severe challenges to their cooling design. Current relevant research mostly focuses on convective heat transfer optimization but generally neglects the critical impact of thermal radiation on cooling performance, and rarely conducts systematic comparisons of radiation responses across multiple cooling structures. To address this gap, the study employs numerical-experimental approach to systematically investigate the flow and heat transfer characteristics of three typical cooling structures under thermal radiation. Results indicate that the presence of thermal radiation reduces the cooling effectiveness, with the film cooling, impingement film cooling, and effusion cooling structures experiencing decreases of 11.24 %, 15.24 %, and 11.56 %, respectively. The variation of radiation heat flux density follows the Stefan-Boltzmann law and exhibits a fourth-power decreasing trend, compared with film cooling structure, the average radiation heat flux density of the impingement film cooling and effusion cooling structures increased by 55.06 % and 94.71 %, respectively. Additionally, this study identifies the optimal blowing ratio around 1 under radiative loads, which enables balancing cooling effectiveness and coolant consumption. The findings of this study provide quantitative support for the design of radiation-adapted cooling structures for high-temperature components in aero-engines, and hold significant engineering value for improving the operational reliability and energy efficiency of engines under extreme high-temperature environments.