Film cooling of leading edge on the vane with a row of CO₂ injection holes

Purpose. Refs.1 to 4 applied air as second flow to obtain a density ratio of 1, we apply CO₂ as second flow to obtain a density ratio of about 1.5 so as to be closer to the real situation in an engine. In the full paper, we explain in detail two things: (1) how to carry out such an experiment; (2) what the experimental results are. In the abstract, we first explain how to carry out such an experiment: The model is blunt body with a half cylinder leading edge and two flat plates. One row of holes is located at two hole diameters from the stagnation line of the leading edge. CO₂ is used to obtain a density of approximately 1.5. High turbulence intensity is produced by a passive grid. Momentum flux ratios varies from 0.5 to 4. The thermocouples are used to measure the temperature of the surface. Then, we give the experimental results and their corresponding analysis presented as Nu/Re^0.5, cooling effectiveness and heat load. On the basis of the experimental result and analysis, we give the following three conclusions: (1) Nu/Re^0.5 with film cooling is much greater than that without film cooling. Nu/Re^0.5 increases with the increase of momentum flux ratios in the case of film cooling. (2) Cooling effectiveness decreases with the increase of momentum flux ratios. Along the mainstream flow direction, cooling effectiveness first increases and then decreases. (3) Heat load reduces when the low momentum flux ratios are low and increases when the momentum flux ratios are high.