Experiments were conducted to investigate the heat transfer characteristics of a typical cooling structure of blade tip clearance active control system with 45 degree inclined impingement.In experiments

jet Reynolds number Re(33297～83242) and the ratio of jet impingement distance to the diameter of the jet hole H/d(2～6) were changed.Heated foil and infrared thermal imaging technology were used to investigate the local Nu(Nusselt number) and Nu(average Nusselt number) by varying those parameters.It was found that there existed two peaks of heat transfer coefficient along the jet line

located at the main and secondary stagnation points respectively.The two peaks were more evident in larger Re and smaller H/d cases.The experimental results show that the flow characteristics are significantly strengthened with the increase of Re increasing

which results in much larger Nu and Nu.With H/d decrease

the local heat transfer at the main stagnation point increases faintly

meanwhile

the local heat transfer at the secondary stagnation point is enhanced greatly.