Heat transfer and flow structure characteristics of film-cooled leading edge model with sweeping and normal jets

Abstract

The heat transfer and flow structure characteristics of a film-cooled leading edge model with sweeping and normal jets were numerically investigated using the conjugate heat transfer method. The leading edge model is a simplified obtuse body model that has three rows of traditional cylindrical film holes, each with three holes inclined at 25° with respect to the surface and three angles oriented at 0° and ± 30° with respect to the axial direction. A normal jet has one row of cylindrical impingement nozzles, and a sweeping jet has only one fluidic oscillator. Three blowing ratios (M = 1.05, 2.07, and 4.11) and three temperature ratios (TR = 0.5, 0.625, and 0.75) are considered in the study. The shear stress transport k–ω turbulence model and an extremely fine structured grid were validated and applied to all simulations. The results indicate that the total pressure loss coefficient and heat transfer performance increase internally and externally, respectively, with the blowing ratio. However, they are insensitive to the temperature ratio in all cooling configurations. The sweeping jet and film (SJF) composite cooling exhibits 1.6162, 2.1195, and 2.1766 times the total pressure loss coefficient of the normal jet and film composite cooling when the blowing ratio increases from 1.05 to 4.11. However, the SJF offers the advantages of uniform Nusselt number distribution on the impinging surface and high overall cooling effectiveness on the external surface.