A cooled turbine airfoil performance prediction method with two-dimensional CFD computation and loss models

Abstract The role of turbine blade cooling and coolants are significant factors in modern gas turbine aerodynamic design. This paper presents an effective and rapid airfoil design method based on CFD computation of the S1 surface and the existing loss correlations. The method can assess the coolant mixing loss by identifying each cooling hole separately and obtain the overall mainflow aerodynamic loss for cooled airfoil. The CFD computation code of the S1 surface is powered by a two-dimensional Euler equation, which is inviscid. Typical Kacker–Okapuu empirical correlations are then used to assess the airfoil friction loss, trailing edge loss, and shock loss. A novel form of the Hartsel model for coolant mixing loss is developed and employed in the CFD codes. In the reformed model, the mixing loss coefficient is directly associated with the blowing ratio and the total pressure/temperature ratio of mainstream-to-coolant, making it more convenient than the original model in the airfoil design process. Based on a transonic turbine vane airfoil, the influences of the film outflow location and outflow Mach number on the coolant mixing loss are investigated using the above prediction method and the cascade blowing test.