Investigation on heat transfer of a rotor blade tip with various film cooling holes arrangements and groove depths

In this article, the effects of film cooling holes arrangement and groove depth on the heat transfer and film cooling performance of blade tip are investigated. For this numerical research, a high-pressure turbine blade with the squealer tip is applied, and the tip clearance is given to be 0.8 mm (1% of the blade span). Simultaneously, a typical tip cooling technology of film holes in the groove floor is used. The number of film holes is fixed at 10, and two kinds of holes arrangements are considered: (1) equidistance distribution and (2) dense distribution near the leading edge. Three groove depths are studied with the values of 1.5, 2.0, and 2.5 mm (1.875%, 2.5%, and 3.125% of the blade span, respectively). The results show that the area-averaged film cooling effectiveness is higher when the holes distribute densely near the leading edge, and the cooling effect of the groove depth with 2.0 mm is obviously high compared with the other two depths.