Effect of the relative position between film cooling holes and ribs on the film cooling effectiveness and heat transfer in a channel with cross-flow and ribs was investigated numerically.The effect of position where film cooling holes were close to upstream ribs

downstream ribs and in the middle region of ribs on the cooling effect was studied with blowing ratio of 0.5

1 and 2

with cross-flow ratio of 0.39

0.585 and 0.78.The results show that

in the case of the film cooling hole entrance in the middle of two ribs

the flow in the hole are influenced heavily by the entrance jet

the heat transfer coefficient and film cooling effectiveness are higher.In the case of the film cooling hole entrance near the up-stream rib

the heat transfer coefficient and film cooling effectiveness are lower.