The effect of main flow orientation angle on the film cooling characteristics of single row of cylindrical film cooling holes was numerically studied. With the same distance between the centers of film cooling holes when the blowing ratio was 1.0

results were compared with two other reference flow configurations of single row of cooling holes. Main flow orientation angle was 0 degree and the hole compound angle was 0 degree in one reference configuration

while main flow orientation angle was 0 degree and the hole compound angle was 45 degree in the other reference configuration. The results show that compared with the reference configuration with 0 degree main flow orientation angle and 0 degree hole compound angle

the film cooling effectiveness of the configuration with 45 degree orientation angle is more uniform and its average cooling effectiveness is higher; compared with the reference configuration with 45 degree compound angle

the average cooling effectiveness of the configuration with 45 degree orientation angle is lower in the region near the holes but higher in the region far away from the holes. Numerical simulations were also conducted when blowing ratios were 0.5 and 1.5. It is found that the distributions of film cooling effectiveness in the three flow configurations are obviously different from each other. So it is necessary to further investigate numerically and experimentally the effect of main flow orientation angle on the film cooling.