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Experimentation research was conducted for studying the effect of blowing ratio ( M) as well as cross flow Reynolds number ( Rec) on distribution characteristics in film cooling effectiveness and heat transfer coefficient ( h) on compound angle hole configuration with applying transient liquid crystal (TLC) technology. The distribution characteristics of discharge coefficient ( Cd) were measured by the flow resistance experiment. The net heat flux reduction (NHFR) is applied for assessing the film cooling performance. Numerical simulation was carried out to present the flow features for analyzing the film cooling mechanism. Results demonstrate that the measured Cd shows upward tendency with the increase of M and is almost no change until M increases to a certain extent. At small M, the measured film cooling effectiveness is higher and descends with the increase of Rec. At the large M, the measured film cooling effectiveness is lower and presents the slight influence on the rises with the increase of Rec. The increase of M makes the measured h descend. The increase of Rec makes the measured h rise. And the NHFR shows the decreasing tendency with the increasing M. A The NHFR decreases in the increase of Rec at M=0.5 and M=2.0. The increase of Rec presents the slight influence on the NHFR under the condition of M =1.0.

To verify the applicability of upstream ribs in film cooling, the present numerical study examines heat transfer characteristics and flow field for ribs located upstream of the film hole. Five ribs including bilaterally truncated ribs, centrally truncated ribs, and continuous ribs are explored with the smooth case at two blowing ratios and fixed crossflow Reynolds number. The results show that the film cooling effectiveness of cases with ribs outperforms the case without rib at a low blowing ratio. Centrally truncated ribs and continuous ribs provide superior cooling effectiveness than bilaterally truncated ribs and smooth cases. The introduction of ribs makes the distribution of the heat transfer coefficient (HTC) uneven after the hole. Among these, centrally truncated ribs increased the HTC, while bilaterally truncated ribs reduce the HTC in the far hole area at a high blowing ratio. It is found that anti-kidney-shaped vortex pairs are generated between two adjacent jets for centrally truncated rib cases, while they are generated in front of the jets for bilaterally truncated rib cases. For continuous rib, the impingement of the mainstream gas on the jet leads to a reduction in strength of the kidney-shaped vortex, which allows the coolant to form a better coverage.

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