Recently, film cooling has been continuously studied to increase the efficiency of gas turbines. A turbine inlet temperature increase occurs as a way to improve the efficiency. However, it is essential to improve the cooling performance of the blade surface because of the melting point of the part. In this paper, a side hole shape wherein a general cylinder hole and two auxiliary holes are combined, is proposed to improve the film cooling efficiency, and the blowing ratio was set to 0.4, 0.8, 1.2, and 2.0. When side hole was applied, the vortex interference at the hole entrance occurred less than that of the cylinder hole. That is, the flow rate of the coolant adsorbed to the surface increased to improve the cooling performance. In conclusion, compared to the cylinder hole, the cooling efficiency of the shape to which the side hole was applied was excellent, and in particular, the average area cooling efficiency with spanwisely designed side holes improved by 83%.

Research on advanced cooling system design is significant in achieving a high turbine inlet temperature in the gas turbine industry. The higher turbine inlet temperature of the gas turbine increases thermal efficiency. However, it also aggravates the gas turbine deterioration, lifespan, and efficiency. In this study, a numerical model is developed for simulating the cooling performance of the gas turbine vane with the turbine inlet temperature of 1528 K. The impact of the coolant air flow rate and hole-shape were investigated. The expanded hole shape had better cooling performance than the general cylindrical shape, and showed higher cooling efficiency. We suggest that there is a relationship between the shape of the film cooling holes and the cooling air flow rate that achieves the desired cooling effectiveness.