Effect of film hole diameter and attack angle on the film cooling performance of leading edge with double swirl chamber under crossflow condition

Abstract

The film cooling characteristics of the blade leading edge with a double swirl chamber are studied experimentally under crossflow(CF) conditions. Aerodynamic and structural parameters such as CF intensity, blowing ratio(BR, 0.5–1.5), film hole diameter(df, 2–4 mm), and attack angle(αa, 0-16°) are considered comprehensively in the experiment. The computational simulation method was introduced to reveal the mechanism of CF affecting the cooling performance. The results present that introducing the CF condition at the same BR condition led to BR redistribution in the film holes, significantly improving the cooling protection near the C1 film holes for the df=3 mm and df=4 mm cases. Unlike the adverse effects of CF on the heat transfer in previous studies, the results present that CF under low BR conditions can help avoid the mainstream intrusion of the film holes. In the case of αa=8° and 16°, The film cooling effectiveness performs the highest in the CF0-BR1.0 condition at s/df>8, and the equivalent film coverage can be obtained under the CF1-BR0.5 condition. CF at αa=8° similarly avoids the mainstream intrusion under the small BR, but the CF reduces η near the C2– film holes. In contrast, the CF has little effect on the cooling performance around the C2– film holes in the case of αa=16° under BR=0.5. The area-averaged film cooling effectiveness of CF2-BR0.5 improves by 85 % relative to CF0-BR0.5 at df=3 mm case. When df=4 mm, the area-averaged film cooling effectiveness enhancement of the CF1-BR1.0 condition is about 87.43 % higher than that of CF0-BR1.0.