Aerodynamic Effects on Heat Transfer for Vane With Shaped Film Holes

Abstract In a low-speed wind tunnel facility, experimental research is conducted to investigate the heat transfer coefficient (hf) distribution on the surface of a full-film vane with shaped holes using the transient liquid crystal (LC) thermography technique. The experiment explores the variation of hf on the vane surface with several aerodynamic variables, including mass flow ratio (MFR), turbulence intensity (Tu), Reynolds (Re) number, and density ratio (DR). MFR varies from 5.5% to 12.5%, Tu varies from 2% to 15%, Re varies from 300,000 to 500,000, and DR varies from 1.0 to 1.5. Eighteen rows of film holes, some of which are shaped holes, are located on the vane surface. The experimental results indicate that the outflow of coolant significantly alters and enhances the hf distribution on the suction surface, with the highest hf observed at the exit of the pressure-side film holes, gradually decreasing along the flow direction. Increasing MFR and Tu enhances the mixing of the mainstream with the coolant, thereby enhancing hf. Moreover, the enhancing effect of Tu on hf diminishes with increasing MFR. Increasing Re significantly enhances the hf due to increased flow velocity. The impact of increased DR on hf varies across different regions of the vane.