Asymmetrical Compound-Angle on Combined-Hole Film Cooling

Abstract

In a modern gas turbine, a film cooling system was applied to provide thermal protection on the turbine components due to high turbine inlet temperatures. Enhanced film cooling effectiveness was formed through the combined-hole film cooling with various parameters. Due to limited research on the asymmetrical compound-angle, ?1 / ?2 on the combined-hole film cooling, the present work was worked on it. The effect of distance between two combined-holes in mainstream direction, LoD and different blowing ratio, M also covered in this work. All considered cases were simulated and the best arrangement of combined-hole film cooling will be determined. Based on different geometrical parameters; LoD and ?1 / ?2 applied, insignificant changes were observed. Meanwhile, a huge change was observed as the blowing ratio increase. As been observed, lateral coverage film cooling effectiveness was spread wider as blowing ratio increase but a drastic decrease of film cooling effectiveness was occurred at further downstream due to early separation and lift-off of the cooling air.