Film Cooling Comparison of Full-Scale Turbine Vanes Using the Pressure Sensitive Paint Technique

This work is an experimental study of film cooling effectiveness on two real-scale turbine vanes in a three-vane annular cascade. The cascade is connected to a high-flow steady compressor to provide the mainstream flow. The inlet velocity is maintained at 35 m/s at the centerline of the annular cascade. Two heavily cooled, real-scale turbine vanes are tested with cooling holes on the pressure (PS) and suction (SS) surfaces. Vane 1 has 645 cooling holes distributed around the vane. Vane 2 has an additional two rows of holes at the near leading edge SS of the vane. The mass flow ratio (MFR) is varied from 3.12% to 4.82%. Increasing the MFR increases film effectiveness. The introduction of additional rows of cooling holes resulted in the re-distribution of coolant from the pressure surface to the suction surface. The re-distribution of coolant is primarily due to the additional coolant supplied to the suction surface for vane 2. This study provides designers with more insight into how to place rows of cooling holes to have improved effectiveness.