Numerical study on the cooling characteristics of cat-ear-shaped film-cooling holes on turbine blades

The turbine blade cooling technology is developing rapidly, with film cooling being the focus of research. To address the problems of poor cooling performance and low cooling efficiency of existing film holes, this paper proposes a hole structure of cat-ear-shaped films on the basis of hyperbola. The structural parameters of the proposed structure, such as inclination angle, expansion angle, length-to-diameter ratio, aperture, and cooling air inlet speed, were simulated and optimised using the finite-volume method and standard k-E model. Furthermore, to meet the requirements of practical applications, the distribution of the film holes on a planar model was optimised numerically. The results revealed that at a hole pitch and row spacing of 5 and 20 mm, respectively, the cooling air flow exhibited patch-shaped coverage and reasonable distribution. This configuration improved the uniformity of air flow coverage and achieved a cooling efficiency of 80.12%, which was 13.12% higher than the average cooling efficiency of previously reported film holes. The cat-ear-shaped film hole demonstrated a remarkable cooling effect, which can provide a reference for optimising and selecting film hole structures on high-temperature turbine blades.