Film cooling performance of fan-shaped film hole on blade pressure side in linear transonic cascade

Film cooling performance of blade pressure side was tested in a linear transonic cascade. The film cooling effectiveness of the fan-shaped film hole on blade pressure side was measured at different mainstream inlet Reynolds numbers of 17×105, 37×105，57×105, different mainstream exit Mach numbers of 081, 091，101 and different blowing ratios of 05-30. Results showed that the mainstream exit Mach number had no distinct effect on the film cooling effectiveness at downstream film hole; however, the mainstream inlet Reynolds number had a significant effect on the film cooling effectiveness. The blowing ratio corresponding to distinguish the film’s lifting off increased with the added mainstream inlet Reynolds number, the film began to lift off at blowing ratio of 10 at mainstream inlet Reynolds number of 17×105 while these corresponding to mainstream inlet Reynolds number of 37×105 and 57×105 were blowing ratios of 20 and 25. At small blowing ratios, the case with higher mainstream inlet Reynolds number had a lager film cooling effectiveness at the region adjacent to the hole and a lower film cooling effectiveness at downstream area; however, at high blowing ratios, higher mainstream inlet Reynolds number resulted in lower film cooling effectiveness.