Hole arrangement effect to film cooling performance on leading edge region of rotating blade

The effect of relative position of two rows of film holes on film cooling performance was experimentally and numerically investigated on each side (suction side and pressure side) of rotating blade leading edge. The film cooling performance was measured by pressure sensitive paint and phase-locked techniques. The numerical simulation was also employed to improve the understanding of flow filed. The first row of film holes is fixed at alpha 1 = +/- 10 degrees downstream of stagnation line and is followed by the second row of holes with staggered arrangement. The span-wise relative positions between two rows of holes, P2/P1, are ranged from 1/4 to 3/4. Meanwhile, the stream-wise location of second row of holes is varied from alpha 2 = +/- 25 degrees; to +/- 40 degrees Five blowing ratios ranged from 0.5 to 2.0 are also employed. The results indicate that the effect of relative position of two rows on film cooling is different on the two sides of leading edge. On the suction side, the relative position between two rows of holes significantly affects the interaction between the adjacent jets from two rows, which determines the distribution and value of film cooling effectiveness. When it comes to the leading edge pressure side, closer distance between two adjacent holes in two rows produces better film cooling performance. Meanwhile, the effect of relative position between two rows of holes is mainly located in the near hole region.