Abstract:

Effects of hole shapes on film cooling effectiveness downstream of film cooling holes were 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 ratio ranging from 0.3 to 2.0. Measurements are taken for 26 conditions. Results show that the optimal blowing ratio is 1.0 for the cone shaped holes, 0.7 for the dust pan shaped holes and 0.5 for the round holes. The film cooling effectiveness and cooled area of dust pan shaped holes and cone shaped holes are evidently superior to those of round holes in cases of blowing ratios greater than 0.7.

Key words: dust-pan shaped hole, cone-shaped hole, film cooling effectiveness, optimal blowing ratio