FILM-COOLING PERFORMANCE OF CYLINDRICAL AND CRATERED HOLES FED BY A PERPENDICULAR CROSSFLOW

Recent studies have proven that a coolant crossfl ow infl uences the cooling performance of fi lm-cooling gas turbine holes. The present paper evaluates the cooling performance for several innovative cratered fi lm-cooling holes fed by a perpendicular crossfl ow channel. The fl ow fi elds, discharge coeffi cients, and the cooling eff ectiveness are analyzed and compared based on the results predicted by the methods of computational fl uid dynamics (CFD) for cylindrical, concentric cratered, and contoured cratered holes. The investigated blowing ratio varies from 0.5 to 2.0. The ratio of the velocity at the crossfl ow channel inlet to the mainstream fl ow velocity is equal to 0.6. The study indicates that the character of the vortex pair and the velocity distribution depend on the specifi c hole shape and blowing ratio. A contoured cratered hole is shown to provide a higher cooling eff ectiveness than cylindrical and concentric cratered holes. In addition, it exhibits the highest discharge coeffi cients everywhere over the range of the blowing ratios studied.
   
Author:  Y. C. Shi, C. Zhang, Z. Sun, Y. X. He
Keywords:  fi lm cooling, cylindrical hole, cratered hole, cooling eff ectiveness, discharge coeffi cient, numerical computation
Page:  482