Effect of Aspect Ratio on Heat Transfer of Triangular Internal Cooling Channel of Gas Turbine Blade

This study investigated the flow and heat transfer characteristics of the triangular internal passage of the leading edge of a gas turbine blade with respect to the aspect ratio. Aspect ratios of 1:0.5, 1:1, and 1:2 were compared using numerical simulations. The simulations were conducted under the condition of Re = 10,000. The results demonstrated that the 1:0.5 aspect ratio case exhibited higher strength of the secondary flow. Therefore, relatively high heat transfer distributions were observed near the leading edge region. However, the 1:1 aspect ratio case exhibited higher average heat transfer distributions owing to the complex effect of the main flow by the rib and secondary flow. Therefore, the thermal performance ratio is the highest at the 1:1 aspect ratio channel, and we conclude that the 1:1 aspect ratio is suitable for the internal passage of the blade leading edge.