Experimental and numerical investigations on film cooling characteristics and hole shape improvement of turbine vane at one engine inoperative condition

This study investigates the film cooling characteristics of four cooling schemes of a gas turbine vane at various mass flux ratios (8.0%, 8.5% and 9.0%) using the Pressure Sensitive Paint (PSP) technology. The improved cooling scheme involves the alteration from cylindrical holes to laid-back fan-shaped holes and laid-back holes on the pressure surface and the leading edge. Considering the complex fluctuations of the real engine operating environment, the one engine inoperative (OEI) situation is numerically simulated to explore the turbine vane's cooling performance at varying operating conditions. Experimental and numerical results indicate significantly enhanced film cooling effectiveness of vane with shaped holes (improved cooling schemes) compared to the cylindrical hole (baseline), particularly at higher mass flux ratio (MFR = 9.0%). At three OEI conditions, the film coverage of improved cooling schemes is significant compared to the baseline on the pressure side. When the OEI condition is increased from 100% to 120%, the area-averaged cooling effectiveness of the shaped hole vane decreases by 4.3%, due to the interaction between the freestream and lift-off cooling jet.