The characteristics of the film cooling system with double-jet

round and shaped holes were investigated under the condition of mainstream turbulence 6% and blowing ratio 0.5

0.8

1.0

1.2

1.5 in the study.The pressure sensitive paint (PSP) was implemented in the tests as the main measurement technique.The film cooling effectiveness decreases between blowing ratio 0.8 and 1.5 in the case of round holes

but increases in the whole experimental blowing ratio in the case of shaped holes and double-jet.It indicates that the double-jet restrains the lift-off of the cooling jet.The film cooling effectiveness of double-jet is better than that of the round holes

but poor than that of the shaped holes in the same conditions.Meanwhile

the vortex structures near the three focused holes obtained from the corresponding computations are major causes of the characteristics of the investigated film cooling systems.