Aerothermal performance analysis and knowledge discovery of film holes on the squealer tip of a gas turbine blade

Abstract

This paper aims to explore the effects of the size/location of film holes on gas turbine rotor tips and improve tip aerothermal performance by establishing a knowledge discovery platform. The study is conducted on the squealer tip of the GE_E3 rotor. Firstly, the effects of the size/location parameters of the single film hole at the different regions on the tip are investigated. Under the same working conditions, detailed flow structure and cooling analysis reveal the size/location parameters of a single hole have an effect on local film cooling effectiveness but little effect on aerodynamic loss, especially for the leading edge hole. Then, a knowledge discovery platform is established, which includes optimization design, aerothermal analysis, and data mining. On the squealer tips, by optimizing the size and location parameters of all film holes, the average film cooling effectiveness is increased from 1.301% to 6.132% while the total pressure recovery coefficient almost remains at 91.395%. Further, the analysis of variance (ANOVA) method uncovers that the size/location of the holes on the leading edge have the most important effect on the film cooling performance, and hole diameter exerts a more significant effect than the location. These results indicate that the cooling performance of tips can be improved by expanding the diameter of the film hole and moving forward the holes to the leading edge.