Numerical investigation on flow and heat transfer characteristics of vortex cooling in actual film-cooled leading edge

Abstract This paper numerically investigates the flow and heat transfer characteristics of vortex cooling in an actual film-cooled leading edge. Two cases called Case P and Case S with coolant injection nozzles arranged on the side of leading edge pressure surface and suction surface are involved. Results indicate that the practical mainstream flow generated by the actual blade affects the vortex flow structures and brings about an endwall secondary flow. For internal vortex cooling, the large-scale vortex flow structures in Case P skew off while flow structures in Case S are not distinctly influenced. Two type of flow regimes form near the film hole due to the suction effect, and bring about different local heat transfer augmentation intensity. For film cooling, the endwall secondary flow forces the coolant film move towards or away from the endwall thus decreases the film cooling efficiency. The film hole blowing ratio distribution is affected due to the different influence of mainstream flow on internal vortex flow of Case P and Case S, which results in different film cooling efficiency distribution. The film cooling efficiency of Case S on the pressure surface increases by up to 59.8% compared with Case P.