Effects of Film Cooling Hole Shape on Heat Transfer

The Effects of hole shapes,secondary flow Reynolds numbers,and blowing ratio on the heat transfer downstream of film cooling holes have been investigated.Experiments on dust-pan shaped holes,cone-shaped holes and round holes have been conducted with secondary flow Reynolds number ranging from 10,000 to 25,000 and blowing rate ranging from 0 3 to 2 0.Measurements are taken for 26 conditions.Results show that the critical blowing ratio is 1 3 for the dust-pan shaped holes and cone-shaped holes,0 7 for the round holes.The turbulence provided by jet from round holes is greater than that from dust-pan shaped holes and cone-shaped holes.